/**
 * File: app-style.css
 * Description: Mobile-Only Stylesheet cho ứng dụng học tập Luc Sensei.
 * Version: 5.0 (Mobile-First Architecture)
 * Features: Mobile-optimized, Touch-friendly, Performance-focused
 */

:root {
  --bottom-nav-height: 80px;
  --top-header-height: 50px;
  --primary-color: #0d6efd;
  --text-color: #6c757d;
  --text-color-active: #0d6efd;
  --flashcard-back-bg: #2c3e50;
}
html,
body {
  min-height: 100%;
  background-color: #f8f9fa;
}
body {
  padding-top: var(--top-header-height);
  padding-bottom: var(--bottom-nav-height);
  -webkit-tap-highlight-color: transparent;
}

/* ==================================================================== */
/* Bố cục Header Trái - Giữa - Phải */
/* ==================================================================== */

.top-header {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  height: var(--top-header-height);
  background-color: #ffffff;
  border-bottom: 1px solid #dee2e6;
  z-index: 1030;
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 0 1rem;
  gap: 1rem;
}

.header-side-left,
.header-side-right {
  flex: 1;
  display: flex;
  align-items: center;
}
.header-side-left {
  justify-content: flex-start;
}
.header-side-right {
  justify-content: flex-end;
}
.header-center {
  flex-grow: 1;
  text-align: center;
}
.app-title {
  font-weight: 600;
  font-size: 1.2rem;
  color: var(--primary-color);
  white-space: nowrap;
}
.btn-header-action {
  border: none;
  background: none;
  font-size: 1.5rem;
  padding: 0.5rem;
  color: #6c757d;
  transition: color 0.2s ease;
  line-height: 1;
}
.btn-header-action:hover {
  color: var(--primary-color);
}
.user-profile .user-avatar {
  border-radius: 50%;
  border: 2px solid #dee2e6;
  object-fit: cover;
  transition: border-color 0.2s ease;
}
.user-profile a:hover .user-avatar {
  border-color: var(--primary-color);
}
.login-button {
  padding: 0.375rem 0.8rem;
  font-weight: 500;
  font-size: 0.9rem;
  white-space: nowrap;
}
.dropdown-menu {
  --bs-dropdown-link-active-bg: var(--primary-color);
}

.gamify-stats-container {
  display: flex;
  align-items: center;
  gap: 0.75rem;
}
.gamify-stat {
  display: flex;
  align-items: center;
  background-color: #f1f3f5;
  padding: 0.25rem 0.6rem;
  border-radius: 20px;
  font-weight: 500;
  color: #495057;
  font-size: 0.9rem;
}
.gamify-stat i {
  font-size: 1.1em;
  margin-right: 0.25rem;
}
[data-bs-theme="dark"] .gamify-stat {
  background-color: #2d2d2d;
  color: #dee2e6;
}
[data-bs-theme="dark"] .btn-header-action {
  color: #adb5bd;
}

/* Course Switcher */
.course-switcher-container {
  display: flex;
  align-items: center;
}

.course-switcher-container select {
  background-color: #f8f9fa;
  border: 1px solid #dee2e6;
  border-radius: 6px;
  padding: 0.25rem 0.5rem;
  font-size: 0.85rem;
  color: #495057;
  min-width: 120px;
  max-width: 180px;
}

.course-switcher-container select:focus {
  border-color: var(--primary-color);
  box-shadow: 0 0 0 0.2rem rgba(13, 110, 253, 0.25);
  outline: none;
}

.course-switcher-container select option {
  padding: 0.25rem;
}

[data-bs-theme="dark"] .course-switcher-container select {
  background-color: #2d2d2d;
  border-color: #495057;
  color: #dee2e6;
}

/* ==================================================================== */
/* NEW DASHBOARD STYLES */
/* ==================================================================== */

.dashboard-container {
  max-width: 1200px;
  margin: 0 auto;
  padding: 0.25rem 1rem 2rem 1rem;
}

/* Progress Section */
.progress-section {
  margin-bottom: 2rem;
}

.progress-section .card {
  border: none;
  border-radius: 16px;
  box-shadow: 0 4px 20px rgba(0, 0, 0, 0.08);
  transition: all 0.3s ease;
}

.progress-section .card:hover {
  transform: translateY(-2px);
  box-shadow: 0 8px 30px rgba(0, 0, 0, 0.12);
}

.progress-section .card-header {
  background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
  color: white;
  border: none;
  border-radius: 16px 16px 0 0;
  padding: 1rem 1.5rem;
  font-weight: 600;
  display: flex;
  align-items: center;
  gap: 0.75rem;
}

.progress-section .card-header i {
  font-size: 1.25rem;
}

.progress-section .card-body {
  padding: 1.5rem;
}

.progress-item {
  display: flex;
  justify-content: space-between;
  align-items: center;
  padding: 0.75rem 0;
  border-bottom: 1px solid #f1f3f4;
}

.progress-item:last-child {
  border-bottom: none;
}

.progress-label {
  font-weight: 500;
  color: #495057;
  flex: 1;
}

.progress-value {
  font-weight: 600;
  color: #667eea;
  margin-left: 1rem;
}

.progress-bar-custom {
  height: 8px;
  background-color: #e9ecef;
  border-radius: 4px;
  overflow: hidden;
  margin-top: 0.5rem;
}

.progress-bar-fill {
  height: 100%;
  background: linear-gradient(90deg, #667eea, #764ba2);
  border-radius: 4px;
  transition: width 0.8s ease;
}

/* Actions Section - Extra bottom margin */
.actions-section {
  margin-bottom: 3rem;
}

.actions-section .card {
  border: none;
  border-radius: 16px;
  box-shadow: 0 4px 20px rgba(0, 0, 0, 0.08);
  transition: all 0.3s ease;
}

.actions-section .card:hover {
  transform: translateY(-2px);
  box-shadow: 0 8px 30px rgba(0, 0, 0, 0.12);
}

.actions-section .card-header {
  background: linear-gradient(135deg, #51cf66 0%, #40c057 100%);
  color: white;
  border: none;
  border-radius: 16px 16px 0 0;
  padding: 1rem 1.5rem;
  font-weight: 600;
  display: flex;
  align-items: center;
  gap: 0.75rem;
}

.actions-section .card-header i {
  font-size: 1.25rem;
}

.actions-section .card-body {
  padding: 1.5rem;
}

.action-item {
  display: flex;
  align-items: center;
  gap: 1rem;
  padding: 1rem;
  border: 1px solid #e9ecef;
  border-radius: 12px;
  margin-bottom: 0.75rem;
  transition: all 0.3s ease;
  cursor: pointer;
  text-decoration: none;
  color: inherit;
}

.action-item:hover {
  background-color: #f8f9fa;
  border-color: #667eea;
  transform: translateX(4px);
  text-decoration: none;
  color: inherit;
}

.action-item:last-child {
  margin-bottom: 0;
}

.action-icon {
  width: 48px;
  height: 48px;
  background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
  border-radius: 12px;
  display: flex;
  align-items: center;
  justify-content: center;
  color: white;
  font-size: 1.25rem;
  flex-shrink: 0;
}

.action-content {
  flex: 1;
}

.action-title {
  font-weight: 600;
  color: #495057;
  margin-bottom: 0.25rem;
}

.action-description {
  font-size: 0.875rem;
  color: #6c757d;
  margin: 0;
}

/* Welcome Section - Enhanced with Animated Wave */
.welcome-section {
  margin-bottom: 1rem;
  position: relative;
}

.welcome-card {
  background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
  border: none;
  border-radius: 20px;
  padding: 1.5rem 2rem;
  color: white;
  box-shadow: 0 8px 32px rgba(102, 126, 234, 0.3);
  transition: all 0.4s cubic-bezier(0.4, 0, 0.2, 1);
  position: relative;
  overflow: hidden;
}

.welcome-card::before {
  content: "";
  position: absolute;
  top: -50%;
  right: -20%;
  width: 200px;
  height: 200px;
  background: radial-gradient(
    circle,
    rgba(255, 255, 255, 0.1) 0%,
    transparent 70%
  );
  border-radius: 50%;
  animation: float 6s ease-in-out infinite;
}

.welcome-card::after {
  content: "";
  position: absolute;
  bottom: -30%;
  left: -10%;
  width: 150px;
  height: 150px;
  background: radial-gradient(
    circle,
    rgba(255, 255, 255, 0.05) 0%,
    transparent 70%
  );
  border-radius: 50%;
  animation: float 8s ease-in-out infinite reverse;
}

.welcome-card:hover {
  box-shadow: 0 12px 40px rgba(102, 126, 234, 0.4);
  transform: translateY(-3px) scale(1.02);
}

.welcome-content {
  display: flex;
  align-items: center;
  gap: 1.5rem;
  position: relative;
  z-index: 2;
}

.welcome-icon {
  font-size: 2.5rem;
  animation: wave 2s ease-in-out infinite;
  filter: drop-shadow(0 2px 4px rgba(0, 0, 0, 0.2));
}

.welcome-text {
  flex: 1;
}

.welcome-title {
  font-size: 1.6rem;
  font-weight: 700;
  margin: 0 0 0.5rem 0;
  color: white;
  text-shadow: 0 2px 4px rgba(0, 0, 0, 0.2);
  letter-spacing: -0.025em;
}

.welcome-subtitle {
  font-size: 1rem;
  opacity: 0.9;
  margin: 0;
  color: rgba(255, 255, 255, 0.9);
  font-weight: 500;
  text-shadow: 0 1px 2px rgba(0, 0, 0, 0.1);
}

/* Wave Animation */
@keyframes wave {
  0%,
  100% {
    transform: rotate(0deg);
  }
  25% {
    transform: rotate(-10deg);
  }
  75% {
    transform: rotate(10deg);
  }
}

/* Float Animation */
@keyframes float {
  0%,
  100% {
    transform: translateY(0px) rotate(0deg);
  }
  50% {
    transform: translateY(-20px) rotate(180deg);
  }
}

/* Course Selection Card */
.course-selection-card .card {
  border-radius: 15px;
  background: linear-gradient(135deg, #f8f9fa 0%, #e9ecef 100%);
  border: 1px solid #dee2e6;
}

.course-selection-card .card-body {
  padding: 1.5rem;
}

.course-selection-card .form-select-lg {
  border-radius: 10px;
  border: 2px solid #dee2e6;
  font-size: 1.1rem;
  padding: 0.75rem 1rem;
  transition: all 0.3s ease;
}

.course-selection-card .form-select-lg:focus {
  border-color: #0d6efd;
  box-shadow: 0 0 0 0.2rem rgba(13, 110, 253, 0.25);
}

.current-course-info {
  text-align: right;
}

/* Section Headers - Harmonious */
.section-header {
  text-align: left;
  margin-bottom: 1.5rem;
  padding: 0 0.5rem;
}

.section-title {
  font-size: 1.3rem;
  font-weight: 600;
  color: #495057;
  margin-bottom: 0.5rem;
  display: flex;
  align-items: center;
  gap: 0.5rem;
}

.section-subtitle {
  font-size: 1rem;
  margin: 0;
}

/* Stats Grid */
.stats-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
  gap: 1.5rem;
  margin-bottom: 2rem;
}

.stat-card {
  background: white;
  border-radius: 15px;
  padding: 1.5rem;
  box-shadow: 0 5px 15px rgba(0, 0, 0, 0.08);
  border: 1px solid #e9ecef;
  transition: all 0.3s ease;
  position: relative;
  overflow: hidden;
}

.stat-card:hover {
  transform: translateY(-5px);
  box-shadow: 0 10px 25px rgba(0, 0, 0, 0.15);
}

.stat-card::before {
  content: "";
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  height: 4px;
  background: linear-gradient(90deg, #667eea, #764ba2);
}

.vocab-card::before {
  background: linear-gradient(90deg, #4facfe, #00f2fe);
}

.questions-card::before {
  background: linear-gradient(90deg, #43e97b, #38f9d7);
}

.review-card::before {
  background: linear-gradient(90deg, #fa709a, #fee140);
}

.stat-icon {
  width: 60px;
  height: 60px;
  border-radius: 15px;
  display: flex;
  align-items: center;
  justify-content: center;
  margin-bottom: 1rem;
  font-size: 1.5rem;
  color: white;
}

.vocab-card .stat-icon {
  background: linear-gradient(135deg, #4facfe, #00f2fe);
}

.questions-card .stat-icon {
  background: linear-gradient(135deg, #43e97b, #38f9d7);
}

.review-card .stat-icon {
  background: linear-gradient(135deg, #fa709a, #fee140);
}

.stat-content {
  text-align: center;
}

.stat-number {
  font-size: 2rem;
  font-weight: 700;
  color: #2c3e50;
  margin-bottom: 0.5rem;
}

.stat-label {
  font-size: 1rem;
  color: #6c757d;
  margin-bottom: 1rem;
  font-weight: 500;
}

.stat-progress {
  height: 6px;
  background: #e9ecef;
  border-radius: 3px;
  overflow: hidden;
}

.progress-bar {
  height: 100%;
  background: linear-gradient(90deg, #667eea, #764ba2);
  border-radius: 3px;
  transition: width 0.8s ease;
}

/* Actions Grid */
.actions-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
  gap: 1.5rem;
}

.action-card {
  background: white;
  border-radius: 15px;
  padding: 1.5rem;
  text-decoration: none;
  color: inherit;
  box-shadow: 0 5px 15px rgba(0, 0, 0, 0.08);
  border: 1px solid #e9ecef;
  transition: all 0.3s ease;
  display: flex;
  align-items: center;
  gap: 1rem;
  position: relative;
  overflow: hidden;
}

.action-card:hover {
  transform: translateY(-3px);
  box-shadow: 0 10px 25px rgba(0, 0, 0, 0.15);
  text-decoration: none;
  color: inherit;
}

.action-card::before {
  content: "";
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  height: 3px;
  background: linear-gradient(90deg, #667eea, #764ba2);
}

.vocab-action::before {
  background: linear-gradient(90deg, #4facfe, #00f2fe);
}

.practice-action::before {
  background: linear-gradient(90deg, #43e97b, #38f9d7);
}

.test-action::before {
  background: linear-gradient(90deg, #fa709a, #fee140);
}

.action-icon {
  width: 50px;
  height: 50px;
  border-radius: 12px;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 1.3rem;
  color: white;
  flex-shrink: 0;
}

.vocab-action .action-icon {
  background: linear-gradient(135deg, #4facfe, #00f2fe);
}

.practice-action .action-icon {
  background: linear-gradient(135deg, #43e97b, #38f9d7);
}

.test-action .action-icon {
  background: linear-gradient(135deg, #fa709a, #fee140);
}

.action-content {
  flex: 1;
}

.action-title {
  font-size: 1.2rem;
  font-weight: 600;
  color: #2c3e50;
  margin-bottom: 0.5rem;
}

.action-description {
  font-size: 0.9rem;
  color: #6c757d;
  margin-bottom: 0.5rem;
}

.action-badge {
  display: inline-block;
  background: #f8f9fa;
  color: #6c757d;
  padding: 0.25rem 0.75rem;
  border-radius: 20px;
  font-size: 0.8rem;
  font-weight: 500;
}

.action-arrow {
  color: #6c757d;
  font-size: 1.2rem;
  flex-shrink: 0;
}

/* Dark Theme - Complete */
[data-bs-theme="dark"] .welcome-card {
  background: linear-gradient(135deg, #4a5568 0%, #2d3748 100%);
  box-shadow: 0 8px 32px rgba(74, 85, 104, 0.4);
}

[data-bs-theme="dark"] .welcome-card:hover {
  box-shadow: 0 12px 40px rgba(74, 85, 104, 0.5);
}

[data-bs-theme="dark"] .welcome-card::before {
  background: radial-gradient(
    circle,
    rgba(255, 255, 255, 0.05) 0%,
    transparent 70%
  );
}

[data-bs-theme="dark"] .welcome-card::after {
  background: radial-gradient(
    circle,
    rgba(255, 255, 255, 0.03) 0%,
    transparent 70%
  );
}

[data-bs-theme="dark"] .welcome-title {
  color: #f7fafc;
  text-shadow: 0 2px 4px rgba(0, 0, 0, 0.3);
}

[data-bs-theme="dark"] .welcome-subtitle {
  color: rgba(247, 250, 252, 0.8);
  text-shadow: 0 1px 2px rgba(0, 0, 0, 0.2);
}

[data-bs-theme="dark"] .stat-card,
[data-bs-theme="dark"] .action-card {
  background: #2d2d2d;
  border-color: #495057;
}

[data-bs-theme="dark"] .stat-card-mobile {
  background: #2d2d2d;
  border-color: #495057;
  color: #e9ecef;
}

[data-bs-theme="dark"] .action-card-mobile {
  background: #2d2d2d;
  border-color: #495057;
  color: #e9ecef;
}

[data-bs-theme="dark"] .section-title {
  color: #e9ecef;
}

[data-bs-theme="dark"] .stat-number {
  color: #e9ecef;
}

[data-bs-theme="dark"] .stat-label {
  color: #adb5bd;
}

[data-bs-theme="dark"] .action-title {
  color: #e9ecef;
}

[data-bs-theme="dark"] .action-description {
  color: #adb5bd;
}

[data-bs-theme="dark"] .course-selection-card .card {
  background: linear-gradient(135deg, #2d2d2d 0%, #343a40 100%);
  border-color: #495057;
  color: #e9ecef;
}

[data-bs-theme="dark"] .course-selection-card .form-select-lg {
  background-color: #343a40;
  border-color: #495057;
  color: #e9ecef;
}

[data-bs-theme="dark"] .current-course-info {
  color: #adb5bd;
}

[data-bs-theme="dark"] .current-course-link {
  color: #60a5fa;
}

/* Mobile Optimized Styles */
.stats-grid-mobile {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 0.5rem;
  margin-bottom: 1rem;
}

.stat-card-mobile {
  background: #f8f9fa;
  border-radius: 12px;
  padding: 1rem;
  box-shadow: 0 2px 8px rgba(0, 0, 0, 0.06);
  border: 1px solid #e9ecef;
  text-align: center;
  position: relative;
  overflow: hidden;
  transition: all 0.3s ease;
}

.stat-card-mobile:hover {
  transform: translateY(-2px);
  box-shadow: 0 4px 12px rgba(0, 0, 0, 0.1);
}

.stat-card-mobile::before {
  content: "";
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  height: 3px;
  background: linear-gradient(90deg, #6c757d, #adb5bd);
}

.vocab-card::before {
  background: linear-gradient(90deg, #0d6efd, #6f42c1);
}

.questions-card::before {
  background: linear-gradient(90deg, #198754, #20c997);
}

.review-card::before {
  background: linear-gradient(90deg, #fa709a, #fee140);
}

.stat-icon-mobile {
  width: 35px;
  height: 35px;
  border-radius: 8px;
  display: flex;
  align-items: center;
  justify-content: center;
  margin: 0 auto 0.5rem;
  font-size: 1rem;
  color: white;
}

.vocab-card .stat-icon-mobile {
  background: linear-gradient(135deg, #4facfe, #00f2fe);
}

.questions-card .stat-icon-mobile {
  background: linear-gradient(135deg, #43e97b, #38f9d7);
}

.review-card .stat-icon-mobile {
  background: linear-gradient(135deg, #fa709a, #fee140);
}

.stat-number-mobile {
  font-size: 1.5rem;
  font-weight: 700;
  color: #2c3e50;
  margin-bottom: 0.25rem;
}

.stat-label-mobile {
  font-size: 0.8rem;
  color: #6c757d;
  font-weight: 500;
}

.actions-grid-mobile {
  display: grid;
  grid-template-columns: 1fr;
  gap: 0.75rem;
}

.action-card-mobile {
  background: #f8f9fa;
  border-radius: 12px;
  padding: 1rem;
  text-decoration: none;
  color: inherit;
  box-shadow: 0 2px 8px rgba(0, 0, 0, 0.06);
  border: 1px solid #e9ecef;
  transition: all 0.3s ease;
  display: flex;
  align-items: center;
  gap: 0.75rem;
  position: relative;
  overflow: hidden;
}

.action-card-mobile:hover {
  transform: translateY(-2px);
  box-shadow: 0 4px 12px rgba(0, 0, 0, 0.12);
  text-decoration: none;
  color: inherit;
}

.action-card-mobile::before {
  content: "";
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  height: 3px;
  background: linear-gradient(90deg, #6c757d, #adb5bd);
}

.vocab-action::before {
  background: linear-gradient(90deg, #0d6efd, #6f42c1);
}

.practice-action::before {
  background: linear-gradient(90deg, #198754, #20c997);
}

.test-action::before {
  background: linear-gradient(90deg, #fa709a, #fee140);
}

.action-icon-mobile {
  width: 40px;
  height: 40px;
  border-radius: 10px;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 1.1rem;
  color: white;
  flex-shrink: 0;
}

.vocab-action .action-icon-mobile {
  background: linear-gradient(135deg, #4facfe, #00f2fe);
}

.practice-action .action-icon-mobile {
  background: linear-gradient(135deg, #43e97b, #38f9d7);
}

.test-action .action-icon-mobile {
  background: linear-gradient(135deg, #fa709a, #fee140);
}

.action-content-mobile {
  flex: 1;
}

.action-title-mobile {
  font-size: 1rem;
  font-weight: 600;
  color: #2c3e50;
  margin-bottom: 0.25rem;
}

.action-description-mobile {
  font-size: 0.8rem;
  color: #6c757d;
  margin: 0;
}

/* Responsive */
@media (max-width: 768px) {
  .welcome-card {
    padding: 1.25rem 1.5rem;
    border-radius: 16px;
  }

  .welcome-content {
    gap: 1.25rem;
  }

  .welcome-icon {
    font-size: 2.2rem;
  }

  .welcome-title {
    font-size: 1.5rem;
    margin-bottom: 0.4rem;
  }

  .welcome-subtitle {
    font-size: 0.95rem;
  }

  .welcome-card::before {
    width: 150px;
    height: 150px;
  }

  .welcome-card::after {
    width: 120px;
    height: 120px;
  }

  .section-title {
    font-size: 1.4rem;
  }

  .course-selection-card .row {
    flex-direction: column;
  }

  .current-course-info {
    text-align: center;
    margin-top: 1rem;
  }

  .course-selection-card .form-select-lg {
    font-size: 1rem;
    padding: 0.6rem 0.8rem;
  }
}

/* Mobile-Only Document Content */
.document-content-wrapper {
  background: white;
  border-radius: 16px;
  box-shadow: 0 4px 20px rgba(0, 0, 0, 0.08);
  border: 1px solid #f1f3f4;
  margin: 0 1rem 2rem 1rem;
  padding: 2rem;
}

.document-content {
  font-size: 1.05rem;
  line-height: 1.7;
}

.document-content p {
  margin-bottom: 1.4rem;
}

.document-content ul,
.document-content ol {
  padding-left: 2rem;
  margin-bottom: 1.4rem;
}

/* Mobile-Only Stats Grid */
.stats-grid-mobile {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 1rem;
  margin-bottom: 1rem;
}

.actions-grid-mobile {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 1rem;
}

/* Hide desktop grids on mobile */
.stats-grid {
  display: none;
}

.actions-grid {
  display: none;
}

#search-results-container {
  min-height: 50px;
  max-height: 60vh;
  overflow-y: auto;
}
#search-results-container .list-group-item {
  cursor: pointer;
}
#search-results-container .list-group-item .badge {
  font-size: 0.7rem;
}

/* ==================================================================== */

.bottom-nav {
  position: fixed;
  bottom: 0;
  left: 0;
  right: 0;
  height: var(--bottom-nav-height);
  background: linear-gradient(135deg, #ffffff 0%, #f8f9fa 100%);
  border-top: 1px solid rgba(0, 0, 0, 0.08);
  display: flex;
  justify-content: space-around;
  align-items: center;
  box-shadow: 0 -4px 20px rgba(0, 0, 0, 0.08);
  backdrop-filter: blur(10px);
  z-index: 1030;
  border-radius: 20px 20px 0 0;
}
.bottom-nav a {
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  flex-grow: 1;
  text-decoration: none;
  color: #8e8e93;
  padding: 12px 8px;
  transition: all 0.3s cubic-bezier(0.4, 0, 0.2, 1);
  border-radius: 12px;
  margin: 0 4px;
  position: relative;
  overflow: hidden;
}
.bottom-nav a::before {
  content: "";
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  bottom: 0;
  background: linear-gradient(135deg, var(--primary-color), #0056b3);
  opacity: 0;
  transition: opacity 0.3s ease;
  border-radius: 12px;
  z-index: -1;
}
.bottom-nav a:active {
  transform: scale(0.95);
}
.bottom-nav a i {
  font-size: 1.5rem;
  margin-bottom: 6px;
  transition: all 0.3s ease;
  position: relative;
  z-index: 1;
}
.bottom-nav a span {
  font-size: 0.7rem;
  font-weight: 500;
  transition: all 0.3s ease;
  position: relative;
  z-index: 1;
}
.bottom-nav a.active {
  color: #ffffff;
  font-weight: 600;
  transform: translateY(-2px);
}
.bottom-nav a.active::before {
  opacity: 1;
}
.bottom-nav a.active i {
  transform: scale(1.1);
}
.bottom-nav a:hover:not(.active) {
  color: var(--primary-color);
  transform: translateY(-1px);
}
.bottom-nav a:hover:not(.active) i {
  transform: scale(1.05);
}

/* Add subtle pulse animation for active tab */
@keyframes pulse {
  0% {
    box-shadow: 0 0 0 0 rgba(13, 110, 253, 0.4);
  }
  70% {
    box-shadow: 0 0 0 10px rgba(13, 110, 253, 0);
  }
  100% {
    box-shadow: 0 0 0 0 rgba(13, 110, 253, 0);
  }
}

.bottom-nav a.active::after {
  content: "";
  position: absolute;
  top: 50%;
  left: 50%;
  width: 4px;
  height: 4px;
  background: #ffffff;
  border-radius: 50%;
  transform: translate(-50%, -50%);
  animation: pulse 2s infinite;
  z-index: 2;
}

/* Smooth transitions for all states */
.bottom-nav a {
  will-change: transform, color;
}

/* Enhanced focus states for accessibility */
.bottom-nav a:focus {
  outline: 2px solid var(--primary-color);
  outline-offset: 2px;
}

/* Mobile-specific optimizations */
@media (max-width: 768px) {
  .bottom-nav {
    height: 85px;
    border-radius: 25px 25px 0 0;
  }

  .bottom-nav a {
    padding: 14px 6px;
  }

  .bottom-nav a i {
    font-size: 1.6rem;
    margin-bottom: 8px;
  }

  .bottom-nav a span {
    font-size: 0.75rem;
  }
}
.main-content {
  padding: 0.25rem 0 2rem 0;
  margin: 0;
  width: 100vw;
  max-width: 100vw;
}
#content-display {
  transition: opacity 0.2s ease-in-out;
  margin: 0;
  padding: 0;
  width: 100vw;
  max-width: 100vw;
}
.fade-out {
  opacity: 0 !important;
}

/* MỚI: CSS cho Tab cố định và Tìm kiếm từ vựng */
.vocab-sticky-header {
  position: -webkit-sticky;
  position: sticky;
  /* Dính vào ngay dưới thanh header chính */
  top: var(--top-header-height);
  background-color: var(--bs-body-bg);
  z-index: 1022; /* Cao hơn nội dung nhưng thấp hơn header chính */
  padding-top: 0.5rem;
  padding-bottom: 0.5rem;
  margin: -1rem -1rem 0 -1rem; /* Bù lại padding của .main-content */
  padding-left: 1rem;
  padding-right: 1rem;
}

.fab-container {
  position: fixed;
  bottom: calc(var(--bottom-nav-height) + 20px);
  right: 20px;
  z-index: 1020;
}

.fab-ai-button {
  width: 56px;
  height: 56px;
  border-radius: 50%;
  border: none;
  background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
  color: white;
  box-shadow: 0 8px 25px rgba(102, 126, 234, 0.4);
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 1.6rem;
  cursor: pointer;
  transition: all 0.3s cubic-bezier(0.4, 0, 0.2, 1);
  position: relative;
  overflow: hidden;
}

.fab-ai-button::before {
  content: "";
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  bottom: 0;
  background: linear-gradient(135deg, #764ba2 0%, #667eea 100%);
  opacity: 0;
  transition: opacity 0.3s ease;
  border-radius: 50%;
}

.fab-ai-button:hover {
  transform: scale(1.15) translateY(-2px);
  box-shadow: 0 12px 35px rgba(102, 126, 234, 0.6);
}

.fab-ai-button:hover::before {
  opacity: 1;
}

.fab-ai-button:active {
  transform: scale(1.05) translateY(-1px);
}

.fab-ai-button i {
  position: relative;
  z-index: 1;
  transition: all 0.3s ease;
}

.fab-ai-button:hover i {
  transform: scale(1.1) rotate(5deg);
}

/* AI Chat Pulse Animation */
@keyframes ai-pulse {
  0% {
    box-shadow: 0 8px 25px rgba(102, 126, 234, 0.4);
  }
  50% {
    box-shadow: 0 8px 25px rgba(102, 126, 234, 0.8),
      0 0 0 10px rgba(102, 126, 234, 0.1);
  }
  100% {
    box-shadow: 0 8px 25px rgba(102, 126, 234, 0.4);
  }
}

.fab-ai-button.pulse {
  animation: ai-pulse 2s infinite;
}

/* Floating particles effect */
@keyframes float {
  0%,
  100% {
    transform: translateY(0px);
  }
  50% {
    transform: translateY(-10px);
  }
}

.fab-ai-button::after {
  content: "✨";
  position: absolute;
  top: -3px;
  right: -3px;
  font-size: 0.6rem;
  animation: float 3s ease-in-out infinite;
  opacity: 0.8;
}

.skeleton {
  animation: skeleton-loading 1s linear infinite alternate;
}
@keyframes skeleton-loading {
  0% {
    background-color: hsl(200, 20%, 80%);
  }
  100% {
    background-color: hsl(200, 20%, 95%);
  }
}
.skeleton-card {
  background-color: #fff;
  border-radius: 12px;
  box-shadow: 0 4px 15px rgba(0, 0, 0, 0.08);
  margin-bottom: 1.5rem;
  padding: 1rem;
}
.skeleton-line {
  height: 1.2rem;
  border-radius: 4px;
  margin-bottom: 0.75rem;
}
.skeleton-line:last-child {
  margin-bottom: 0;
}
/* AI Chat Modal Styling */
#ai-chat-modal .modal-content {
  border: none;
  border-radius: 20px;
  box-shadow: 0 20px 60px rgba(0, 0, 0, 0.15);
  overflow: hidden;
  background: linear-gradient(135deg, #ffffff 0%, #f8f9fa 100%);
}

.chat-header {
  background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
  color: white;
  border: none;
  padding: 1.5rem;
  position: relative;
}

.chat-header::before {
  content: "";
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  bottom: 0;
  background: url('data:image/svg+xml,<svg xmlns="http://www.w3.org/2000/svg" viewBox="0 0 100 100"><defs><pattern id="grain" width="100" height="100" patternUnits="userSpaceOnUse"><circle cx="25" cy="25" r="1" fill="white" opacity="0.1"/><circle cx="75" cy="75" r="1" fill="white" opacity="0.1"/><circle cx="50" cy="10" r="0.5" fill="white" opacity="0.1"/><circle cx="10" cy="60" r="0.5" fill="white" opacity="0.1"/><circle cx="90" cy="40" r="0.5" fill="white" opacity="0.1"/></pattern></defs><rect width="100" height="100" fill="url(%23grain)"/></svg>');
  opacity: 0.3;
}

.chat-header .modal-title {
  position: relative;
  z-index: 1;
  font-weight: 600;
  font-size: 1.2rem;
}

.chat-header .modal-title i {
  background: rgba(255, 255, 255, 0.2);
  padding: 8px;
  border-radius: 12px;
  margin-right: 12px;
}

.chat-header .btn-close {
  filter: invert(1);
  opacity: 0.8;
  position: relative;
  z-index: 1;
}

.chat-header .btn-close:hover {
  opacity: 1;
  transform: scale(1.1);
}

.chat-body {
  padding: 1.5rem;
  display: flex;
  flex-direction: column;
  background: linear-gradient(135deg, #f8f9fa 0%, #ffffff 100%);
  min-height: 400px;
}

#chat-output {
  flex-grow: 1;
  overflow-y: auto;
  padding: 1rem 0;
  scroll-behavior: smooth;
}

#chat-output::-webkit-scrollbar {
  width: 6px;
}

#chat-output::-webkit-scrollbar-track {
  background: #f1f1f1;
  border-radius: 3px;
}

#chat-output::-webkit-scrollbar-thumb {
  background: linear-gradient(135deg, #667eea, #764ba2);
  border-radius: 3px;
}

.chat-footer {
  border: none;
  background: linear-gradient(135deg, #ffffff 0%, #f8f9fa 100%);
  display: flex;
  flex-direction: column;
  padding: 1.5rem;
  box-shadow: 0 -4px 20px rgba(0, 0, 0, 0.05);
}

.chat-input-bar {
  display: flex;
  width: 100%;
  gap: 0.75rem;
  align-items: center;
  background: white;
  border-radius: 25px;
  padding: 8px;
  box-shadow: 0 4px 20px rgba(0, 0, 0, 0.1);
  border: 1px solid rgba(102, 126, 234, 0.1);
}

.chat-input-bar .form-control {
  border: none;
  border-radius: 20px;
  padding: 12px 20px;
  background: transparent;
  font-size: 1rem;
  box-shadow: none;
}

.chat-input-bar .form-control:focus {
  box-shadow: none;
  border: none;
  outline: none;
}

.chat-input-bar .btn {
  border-radius: 50%;
  width: 50px;
  height: 50px;
  flex-shrink: 0;
  background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
  border: none;
  display: flex;
  align-items: center;
  justify-content: center;
  transition: all 0.3s ease;
}

.chat-input-bar .btn:hover {
  transform: scale(1.1);
  box-shadow: 0 4px 15px rgba(102, 126, 234, 0.4);
}

.chat-input-bar .btn:active {
  transform: scale(0.95);
}
/* Message Bubbles */
.message-bubble {
  max-width: 85%;
  padding: 15px 20px;
  border-radius: 20px;
  margin-bottom: 1rem;
  position: relative;
  animation: messageSlideIn 0.3s ease-out;
  box-shadow: 0 2px 10px rgba(0, 0, 0, 0.1);
  backdrop-filter: blur(10px);
}

@keyframes messageSlideIn {
  from {
    opacity: 0;
    transform: translateY(20px);
  }
  to {
    opacity: 1;
    transform: translateY(0);
  }
}

.user-bubble {
  background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
  color: white;
  margin-left: auto;
  border-bottom-right-radius: 8px;
}

.user-bubble::before {
  content: "";
  position: absolute;
  bottom: 0;
  right: -8px;
  width: 0;
  height: 0;
  border-left: 8px solid #764ba2;
  border-top: 8px solid transparent;
  border-bottom: 8px solid transparent;
}

.ai-bubble {
  background: linear-gradient(135deg, #f8f9fa 0%, #ffffff 100%);
  color: #2c3e50;
  margin-right: auto;
  border: 1px solid rgba(102, 126, 234, 0.1);
  border-bottom-left-radius: 8px;
}

.ai-bubble::before {
  content: "";
  position: absolute;
  bottom: 0;
  left: -8px;
  width: 0;
  height: 0;
  border-right: 8px solid #f8f9fa;
  border-top: 8px solid transparent;
  border-bottom: 8px solid transparent;
}

.ai-avatar {
  width: 32px;
  height: 32px;
  border-radius: 50%;
  background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
  color: white;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 0.9rem;
  margin-right: 10px;
  flex-shrink: 0;
  box-shadow: 0 2px 8px rgba(102, 126, 234, 0.3);
}

.message-container {
  display: flex;
  align-items: flex-end;
  margin-bottom: 1rem;
}

.message-container.user {
  justify-content: flex-end;
}

.message-container.ai {
  justify-content: flex-start;
}

/* Typing indicator */
.typing-indicator {
  display: flex;
  align-items: center;
  padding: 15px 20px;
  background: linear-gradient(135deg, #f8f9fa 0%, #ffffff 100%);
  border-radius: 20px;
  border-bottom-left-radius: 8px;
  margin-right: auto;
  max-width: 120px;
  border: 1px solid rgba(102, 126, 234, 0.1);
  box-shadow: 0 2px 10px rgba(0, 0, 0, 0.1);
}

.typing-indicator .ai-avatar {
  margin-right: 10px;
}

.typing-dots {
  display: flex;
  gap: 4px;
}

.typing-dots span {
  width: 8px;
  height: 8px;
  border-radius: 50%;
  background: linear-gradient(135deg, #667eea, #764ba2);
  animation: typingDot 1.4s infinite ease-in-out;
}

.typing-dots span:nth-child(1) {
  animation-delay: -0.32s;
}

.typing-dots span:nth-child(2) {
  animation-delay: -0.16s;
}

@keyframes typingDot {
  0%,
  80%,
  100% {
    transform: scale(0.8);
    opacity: 0.5;
  }
  40% {
    transform: scale(1);
    opacity: 1;
  }
}

/* Modal entrance animation */
#ai-chat-modal .modal-dialog {
  animation: modalSlideIn 0.3s ease-out;
}

@keyframes modalSlideIn {
  from {
    opacity: 0;
    transform: translateY(50px) scale(0.9);
  }
  to {
    opacity: 1;
    transform: translateY(0) scale(1);
  }
}

/* Chat suggestions styling */
#chat-suggestions {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
  margin-bottom: 1rem;
}

.chat-suggestion {
  background: linear-gradient(135deg, #f8f9fa 0%, #e9ecef 100%);
  border: 1px solid rgba(102, 126, 234, 0.1);
  border-radius: 20px;
  padding: 8px 16px;
  font-size: 0.9rem;
  color: #495057;
  cursor: pointer;
  transition: all 0.3s ease;
  user-select: none;
}

.chat-suggestion:hover {
  background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
  color: white;
  transform: translateY(-2px);
  box-shadow: 0 4px 15px rgba(102, 126, 234, 0.3);
}

/* Dark mode chat suggestions */
[data-bs-theme="dark"] .chat-suggestion {
  background: linear-gradient(135deg, #2d2d2d 0%, #3d3d3d 100%);
  color: #dee2e6;
  border: 1px solid rgba(102, 126, 234, 0.2);
}

[data-bs-theme="dark"] .chat-suggestion:hover {
  background: linear-gradient(135deg, #4a5568 0%, #2d3748 100%);
  color: white;
}

/* Enhanced focus states */
.chat-input-bar .form-control:focus {
  transform: scale(1.02);
}

/* Loading state for send button */
.chat-input-bar .btn.loading {
  pointer-events: none;
  opacity: 0.7;
}

.chat-input-bar .btn.loading i {
  animation: spin 1s linear infinite;
}

@keyframes spin {
  from {
    transform: rotate(0deg);
  }
  to {
    transform: rotate(360deg);
  }
}

/* ==================================================================== */
/* MOCK TEST MODERN UI */
/* ==================================================================== */

.mock-test-container {
  padding: 0;
  max-width: 600px;
  margin: 0 auto;
}

/* Modern Hero Section */
.mock-test-hero {
  position: relative;
  z-index: 2;
  padding: 2rem 1.5rem 2.5rem;
  text-align: center;
  background: linear-gradient(135deg, #667eea 0%, #764ba2 50%, #f093fb 100%);
  border-radius: 24px;
  margin: 0.5rem;
  margin-bottom: 1.5rem;
  color: white;
  overflow: hidden;
  box-shadow: 0 25px 50px rgba(102, 126, 234, 0.4),
    0 0 0 1px rgba(255, 255, 255, 0.1), inset 0 1px 0 rgba(255, 255, 255, 0.2);
  backdrop-filter: blur(20px);
  border: 1px solid rgba(255, 255, 255, 0.15);
  animation: slideInUp 0.6s ease-out;
  /* Center focus effect */
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  min-height: 220px;
}

.mock-test-hero::before {
  content: "";
  position: absolute;
  top: 50%;
  left: 50%;
  width: 250px;
  height: 250px;
  background: radial-gradient(
    circle,
    rgba(255, 255, 255, 0.1) 0%,
    rgba(255, 255, 255, 0.05) 30%,
    transparent 70%
  );
  border-radius: 50%;
  transform: translate(-50%, -50%);
  animation: centerPulse 4s ease-in-out infinite;
  z-index: 1;
}

.mock-test-hero::after {
  content: "";
  position: absolute;
  top: 50%;
  left: 50%;
  width: 180px;
  height: 180px;
  background: radial-gradient(
    circle,
    rgba(240, 147, 251, 0.15) 0%,
    rgba(240, 147, 251, 0.08) 40%,
    transparent 70%
  );
  border-radius: 50%;
  transform: translate(-50%, -50%);
  animation: centerPulse 6s ease-in-out infinite reverse;
  z-index: 1;
}

@keyframes centerPulse {
  0%,
  100% {
    transform: translate(-50%, -50%) scale(1);
    opacity: 0.3;
  }
  50% {
    transform: translate(-50%, -50%) scale(1.2);
    opacity: 0.6;
  }
}

@keyframes heroFloat {
  0%,
  100% {
    transform: translateY(0px) rotate(0deg) scale(1);
    opacity: 0.6;
  }
  50% {
    transform: translateY(-15px) rotate(180deg) scale(1.05);
    opacity: 1;
  }
}

.hero-icon {
  position: relative;
  z-index: 3;
  width: 110px;
  height: 110px;
  background: rgba(255, 255, 255, 0.25);
  border-radius: 32px;
  display: flex;
  align-items: center;
  justify-content: center;
  margin: 0 auto 1.5rem;
  backdrop-filter: blur(20px);
  border: 1px solid rgba(255, 255, 255, 0.4);
  box-shadow: 0 8px 32px rgba(0, 0, 0, 0.15),
    inset 0 1px 0 rgba(255, 255, 255, 0.3);
  transition: all 0.4s cubic-bezier(0.4, 0, 0.2, 1);
  animation: fadeInUp 0.8s ease-out 0.2s both;
}

.hero-icon:hover {
  transform: translateY(-4px) scale(1.05);
  box-shadow: 0 12px 40px rgba(0, 0, 0, 0.2),
    inset 0 1px 0 rgba(255, 255, 255, 0.4);
  border-color: rgba(255, 255, 255, 0.6);
}

.hero-icon i {
  font-size: 3.5rem;
  color: white;
  filter: drop-shadow(0 2px 4px rgba(0, 0, 0, 0.2));
}

.hero-title {
  position: relative;
  z-index: 3;
  font-size: 3.2rem;
  font-weight: 800;
  margin: 0 0 1rem 0;
  background: linear-gradient(135deg, #ffffff 0%, #f0f9ff 100%);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
  text-shadow: 0 2px 4px rgba(0, 0, 0, 0.3), 0 0 20px rgba(255, 255, 255, 0.1);
  animation: fadeInLeft 0.8s ease-out 0.4s both;
  letter-spacing: -0.025em;
  line-height: 1.2;
}

.hero-subtitle {
  position: relative;
  z-index: 3;
  font-size: 1.4rem;
  color: rgba(255, 255, 255, 0.95);
  margin: 0;
  animation: fadeInLeft 0.8s ease-out 0.6s both;
  text-shadow: 0 1px 2px rgba(0, 0, 0, 0.2), 0 0 10px rgba(255, 255, 255, 0.1);
  font-weight: 500;
  letter-spacing: 0.025em;
  line-height: 1.6;
  max-width: 400px;
  margin: 0 auto;
}

@keyframes slideInUp {
  from {
    opacity: 0;
    transform: translateY(30px);
  }
  to {
    opacity: 1;
    transform: translateY(0);
  }
}

@keyframes fadeInUp {
  from {
    opacity: 0;
    transform: translateY(20px);
  }
  to {
    opacity: 1;
    transform: translateY(0);
  }
}

@keyframes fadeInLeft {
  from {
    opacity: 0;
    transform: translateX(-30px);
  }
  to {
    opacity: 1;
    transform: translateX(0);
  }
}

.hero-subtitle {
  position: relative;
  z-index: 1;
  font-size: 1.1rem;
  opacity: 0.9;
  margin: 0;
  font-weight: 300;
}

/* Setup Card */
.mock-test-setup-card {
  background: white;
  border-radius: 20px;
  box-shadow: 0 10px 40px rgba(0, 0, 0, 0.1);
  overflow: hidden;
  border: 1px solid rgba(102, 126, 234, 0.1);
}

.setup-header {
  background: linear-gradient(135deg, #f8f9fa 0%, #e9ecef 100%);
  padding: 1.5rem;
  display: flex;
  align-items: center;
  gap: 1rem;
  border-bottom: 1px solid rgba(0, 0, 0, 0.05);
}

.setup-icon {
  width: 50px;
  height: 50px;
  background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
  border-radius: 12px;
  display: flex;
  align-items: center;
  justify-content: center;
  color: white;
  font-size: 1.2rem;
}

.setup-title {
  font-size: 1.4rem;
  font-weight: 600;
  color: #2c3e50;
  margin: 0;
}

.setup-content {
  padding: 0;
}

/* Question Count Section */
.question-count-section {
  margin-bottom: 2rem;
}

.section-label {
  display: flex;
  align-items: center;
  gap: 0.5rem;
  font-weight: 600;
  color: #495057;
  margin-bottom: 1rem;
  font-size: 1.1rem;
}

.section-label i {
  color: #667eea;
  font-size: 1.2rem;
}

/* Compact Question Options - Beautiful Modern Design */
.question-options-compact {
  display: flex;
  gap: 1.25rem;
  justify-content: center;
  flex-wrap: wrap;
  padding: 2rem 1rem;
  background: linear-gradient(
    135deg,
    rgba(255, 255, 255, 0.8) 0%,
    rgba(248, 250, 252, 0.6) 100%
  );
  border-radius: 32px;
  box-shadow: 0 20px 60px rgba(0, 0, 0, 0.08),
    0 0 0 1px rgba(255, 255, 255, 0.9), inset 0 1px 0 rgba(255, 255, 255, 0.8);
  backdrop-filter: blur(30px);
  position: relative;
  overflow: hidden;
  border: 1px solid rgba(255, 255, 255, 0.6);
}

.question-options-compact::before {
  content: "";
  position: absolute;
  top: -30%;
  right: -15%;
  width: 200px;
  height: 200px;
  background: radial-gradient(
    circle,
    rgba(99, 102, 241, 0.15) 0%,
    rgba(139, 92, 246, 0.1) 50%,
    transparent 70%
  );
  border-radius: 50%;
  animation: floatGentle 8s ease-in-out infinite;
}

.question-options-compact::after {
  content: "";
  position: absolute;
  bottom: -25%;
  left: -10%;
  width: 150px;
  height: 150px;
  background: radial-gradient(
    circle,
    rgba(59, 130, 246, 0.12) 0%,
    rgba(16, 185, 129, 0.08) 50%,
    transparent 70%
  );
  border-radius: 50%;
  animation: floatGentle 10s ease-in-out infinite reverse;
}

@keyframes floatGentle {
  0%,
  100% {
    transform: translateY(0px) rotate(0deg) scale(1);
    opacity: 0.7;
  }
  50% {
    transform: translateY(-20px) rotate(180deg) scale(1.1);
    opacity: 1;
  }
}

.option-item {
  position: relative;
  cursor: pointer;
  transition: all 0.5s cubic-bezier(0.25, 0.46, 0.45, 0.94);
  overflow: visible;
  z-index: 3;
}

.option-badge {
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  width: 100px;
  height: 100px;
  background: linear-gradient(135deg, #ffffff 0%, #f8fafc 100%);
  border: 3px solid rgba(99, 102, 241, 0.15);
  border-radius: 28px;
  position: relative;
  z-index: 2;
  transition: all 0.5s cubic-bezier(0.25, 0.46, 0.45, 0.94);
  box-shadow: 0 12px 40px rgba(0, 0, 0, 0.08),
    0 0 0 1px rgba(255, 255, 255, 0.9), inset 0 2px 0 rgba(255, 255, 255, 0.8),
    inset 0 -1px 0 rgba(0, 0, 0, 0.05);
  backdrop-filter: blur(25px);
}

.option-badge::before {
  content: "";
  position: absolute;
  top: -2px;
  left: -2px;
  right: -2px;
  bottom: -2px;
  background: linear-gradient(
    135deg,
    rgba(99, 102, 241, 0.2) 0%,
    rgba(139, 92, 246, 0.15) 100%
  );
  border-radius: 30px;
  opacity: 0;
  transition: all 0.4s ease;
  z-index: -1;
}

.option-badge::after {
  content: "";
  position: absolute;
  top: 50%;
  left: 50%;
  width: 0;
  height: 0;
  background: radial-gradient(
    circle,
    rgba(99, 102, 241, 0.3) 0%,
    transparent 70%
  );
  border-radius: 50%;
  transform: translate(-50%, -50%);
  transition: all 0.6s ease;
  z-index: -1;
}

.option-item:hover .option-badge {
  transform: translateY(-6px) scale(1.05);
  box-shadow: 0 20px 60px rgba(99, 102, 241, 0.2),
    0 0 0 1px rgba(99, 102, 241, 0.3), inset 0 2px 0 rgba(255, 255, 255, 1),
    inset 0 -1px 0 rgba(0, 0, 0, 0.1);
  border-color: rgba(99, 102, 241, 0.4);
}

.option-item:hover .option-badge::before {
  opacity: 1;
  transform: scale(1.05);
}

.option-item:hover .option-badge::after {
  width: 120px;
  height: 120px;
}

.option-item.active .option-badge {
  background: linear-gradient(135deg, #6366f1 0%, #8b5cf6 40%, #ec4899 100%);
  color: white;
  border-color: rgba(255, 255, 255, 0.3);
  transform: translateY(-4px) scale(1.08);
  box-shadow: 0 25px 70px rgba(99, 102, 241, 0.35),
    0 0 0 1px rgba(255, 255, 255, 0.2), inset 0 2px 0 rgba(255, 255, 255, 0.4),
    inset 0 -1px 0 rgba(0, 0, 0, 0.1);
}

.option-item.active .option-badge::before {
  opacity: 0;
}

.option-item.active .option-badge::after {
  width: 0;
  height: 0;
}

.option-number {
  font-size: 1.8rem;
  font-weight: 900;
  line-height: 1;
  margin-bottom: 0.4rem;
  color: inherit;
  text-shadow: 0 2px 4px rgba(0, 0, 0, 0.1);
  letter-spacing: -0.03em;
  background: linear-gradient(135deg, currentColor 0%, rgba(0, 0, 0, 0.1) 100%);
  -webkit-background-clip: text;
  background-clip: text;
}

.option-item.active .option-number {
  text-shadow: 0 2px 8px rgba(0, 0, 0, 0.2);
}

.option-time {
  font-size: 0.8rem;
  font-weight: 700;
  opacity: 0.95;
  color: inherit;
  background: rgba(99, 102, 241, 0.12);
  padding: 0.3rem 0.6rem;
  border-radius: 16px;
  backdrop-filter: blur(15px);
  border: 1px solid rgba(99, 102, 241, 0.25);
  text-shadow: 0 1px 2px rgba(0, 0, 0, 0.1);
  letter-spacing: 0.02em;
}

.option-item.active .option-time {
  background: rgba(255, 255, 255, 0.3);
  border-color: rgba(255, 255, 255, 0.4);
  text-shadow: 0 1px 3px rgba(0, 0, 0, 0.2);
}

/* Ripple Effect */
.option-ripple {
  position: absolute;
  top: 0;
  left: 0;
  width: 0;
  height: 0;
  background: rgba(255, 255, 255, 0.3);
  border-radius: 50%;
  transform: scale(0);
  pointer-events: none;
  z-index: 0;
}

.option-ripple.animate {
  animation: ripple-animation 0.6s ease-out;
}

@keyframes ripple-animation {
  0% {
    transform: scale(0);
    opacity: 1;
  }
  100% {
    transform: scale(1);
    opacity: 0;
  }
}

/* Pulse Effect for Active Item */
.option-item.active::before {
  content: "";
  position: absolute;
  top: -4px;
  left: -4px;
  right: -4px;
  bottom: -4px;
  background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
  border-radius: 24px;
  z-index: -1;
  animation: pulse-ring 2s infinite;
}

@keyframes pulse-ring {
  0% {
    transform: scale(0.8);
    opacity: 1;
  }
  100% {
    transform: scale(1.2);
    opacity: 0;
  }
}

/* Glow Effect */
.option-item.active::after {
  content: "";
  position: absolute;
  top: -2px;
  left: -2px;
  right: -2px;
  bottom: -2px;
  background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
  border-radius: 22px;
  z-index: -2;
  filter: blur(8px);
  opacity: 0.6;
  animation: glow-pulse 2s infinite alternate;
}

@keyframes glow-pulse {
  0% {
    opacity: 0.4;
    transform: scale(1);
  }
  100% {
    opacity: 0.8;
    transform: scale(1.05);
  }
}

/* Exam Info */
.exam-info {
  background: linear-gradient(135deg, #f8f9fa 0%, #e9ecef 100%);
  border-radius: 16px;
  padding: 1.5rem;
  margin-bottom: 2rem;
}

.info-item {
  display: flex;
  align-items: center;
  gap: 0.75rem;
  margin-bottom: 0.75rem;
  font-size: 0.95rem;
  color: #495057;
}

.info-item:last-child {
  margin-bottom: 0;
}

.info-item i {
  width: 20px;
  height: 20px;
  background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
  border-radius: 50%;
  display: flex;
  align-items: center;
  justify-content: center;
  color: white;
  font-size: 0.8rem;
  flex-shrink: 0;
}

/* Start Exam Button */
.start-exam-btn {
  width: 100%;
  background: linear-gradient(135deg, #e74c3c 0%, #c0392b 100%);
  border: none;
  border-radius: 16px;
  padding: 1.25rem 2rem;
  color: white;
  font-size: 1.2rem;
  font-weight: 600;
  cursor: pointer;
  position: relative;
  overflow: hidden;
  transition: all 0.3s cubic-bezier(0.4, 0, 0.2, 1);
  box-shadow: 0 8px 25px rgba(231, 76, 60, 0.3);
}

.start-exam-btn:hover {
  transform: translateY(-2px);
  box-shadow: 0 12px 35px rgba(231, 76, 60, 0.4);
}

.start-exam-btn:active {
  transform: translateY(0);
}

.btn-content {
  position: relative;
  z-index: 1;
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 0.75rem;
}

.btn-content i {
  font-size: 1.3rem;
}

.btn-shine {
  position: absolute;
  top: 0;
  left: -100%;
  width: 100%;
  height: 100%;
  background: linear-gradient(
    90deg,
    transparent,
    rgba(255, 255, 255, 0.2),
    transparent
  );
  transition: left 0.5s ease;
}

.start-exam-btn:hover .btn-shine {
  left: 100%;
}

/* Dark Mode Support */
[data-bs-theme="dark"] .mock-test-setup-card {
  background: #2d2d2d;
  border-color: rgba(102, 126, 234, 0.2);
}

[data-bs-theme="dark"] .setup-header {
  background: linear-gradient(135deg, #3d3d3d 0%, #2d2d2d 100%);
  border-color: rgba(255, 255, 255, 0.1);
}

[data-bs-theme="dark"] .setup-title {
  color: #dee2e6;
}

[data-bs-theme="dark"] .section-label {
  color: #adb5bd;
}

[data-bs-theme="dark"] .question-options-compact {
  background: linear-gradient(
    135deg,
    rgba(30, 41, 59, 0.8) 0%,
    rgba(15, 23, 42, 0.6) 100%
  );
  border-color: rgba(71, 85, 105, 0.5);
  box-shadow: 0 20px 60px rgba(0, 0, 0, 0.3), 0 0 0 1px rgba(71, 85, 105, 0.5),
    inset 0 1px 0 rgba(255, 255, 255, 0.1);
}

[data-bs-theme="dark"] .question-options-compact::before {
  background: radial-gradient(
    circle,
    rgba(99, 102, 241, 0.2) 0%,
    rgba(139, 92, 246, 0.15) 50%,
    transparent 70%
  );
}

[data-bs-theme="dark"] .question-options-compact::after {
  background: radial-gradient(
    circle,
    rgba(59, 130, 246, 0.18) 0%,
    rgba(16, 185, 129, 0.12) 50%,
    transparent 70%
  );
}

[data-bs-theme="dark"] .option-badge {
  background: linear-gradient(135deg, #334155 0%, #1e293b 100%);
  border-color: rgba(99, 102, 241, 0.3);
  color: #e2e8f0;
  box-shadow: 0 8px 32px rgba(0, 0, 0, 0.3), 0 0 0 1px rgba(71, 85, 105, 0.5),
    inset 0 1px 0 rgba(255, 255, 255, 0.1);
}

[data-bs-theme="dark"] .option-badge::before {
  background: linear-gradient(
    135deg,
    rgba(99, 102, 241, 0.1) 0%,
    rgba(139, 92, 246, 0.1) 100%
  );
}

[data-bs-theme="dark"] .option-item:hover .option-badge {
  border-color: rgba(99, 102, 241, 0.5);
  box-shadow: 0 16px 48px rgba(99, 102, 241, 0.2),
    0 0 0 1px rgba(99, 102, 241, 0.4), inset 0 1px 0 rgba(255, 255, 255, 0.15);
}

[data-bs-theme="dark"] .option-time {
  background: rgba(99, 102, 241, 0.2);
  border-color: rgba(99, 102, 241, 0.3);
  color: #cbd5e0;
}

[data-bs-theme="dark"] .option-item.active .option-time {
  background: rgba(255, 255, 255, 0.2);
  border-color: rgba(255, 255, 255, 0.3);
}

[data-bs-theme="dark"] .exam-info {
  background: linear-gradient(135deg, #3d3d3d 0%, #2d2d2d 100%);
}

[data-bs-theme="dark"] .info-item {
  color: #adb5bd;
}

/* Mobile Responsive */
@media (max-width: 768px) {
  .mock-test-container {
    padding: 0;
  }

  .mock-test-hero {
    padding: 1.5rem 1rem;
    margin-bottom: 1.5rem;
  }

  .hero-icon {
    width: 60px;
    height: 60px;
  }

  .hero-icon i {
    font-size: 2rem;
  }

  .hero-title {
    font-size: 2rem;
  }

  .hero-subtitle {
    font-size: 1rem;
  }

  .setup-content {
    padding: 0;
  }

  .question-options-compact {
    gap: 1rem;
    padding: 1.5rem 0.75rem;
    border-radius: 24px;
  }

  .question-options-compact::before {
    width: 120px;
    height: 120px;
  }

  .question-options-compact::after {
    width: 100px;
    height: 100px;
  }

  .option-badge {
    width: 85px;
    height: 85px;
    border-radius: 22px;
  }

  .option-number {
    font-size: 1.5rem;
  }

  .option-time {
    font-size: 0.75rem;
    padding: 0.25rem 0.5rem;
    border-radius: 12px;
  }
}

.ai-bubble {
  white-space: pre-wrap;
  word-wrap: break-word;
}
.user-bubble {
  background-color: #0d6efd;
  color: white;
  align-self: flex-end;
  border-bottom-right-radius: 4px;
}
.ai-bubble-container {
  display: flex;
  align-items: flex-start;
  gap: 10px;
  align-self: flex-start;
  max-width: 95%;
}
.ai-avatar {
  width: 32px;
  height: 32px;
  border-radius: 50%;
  background-color: #e9ecef;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 1.2rem;
  color: #495057;
  flex-shrink: 0;
}
.ai-bubble {
  background-color: #f1f3f5;
  color: #212529;
  border-bottom-left-radius: 4px;
}
#chat-suggestions {
  display: none;
  flex-wrap: wrap;
  gap: 8px;
}
.suggestion-chip {
  padding: 6px 12px;
  font-size: 0.9rem;
  border: 1px solid #0d6efd;
  color: #0d6efd;
  background-color: #ffffff;
  border-radius: 16px;
  cursor: pointer;
  transition: all 0.2s ease;
}
.suggestion-chip:hover {
  background-color: #0d6efd;
  color: #ffffff;
}

/**
 * ============================================
 * DDL-MOD: FLASHCARD STYLES - IMPORTED
 * ============================================
 * Flashcard styles have been moved to flashcard-style.css
 * Import the flashcard styles at the top of this file
 */
rt {
  font-size: 0.7em;
}
.vocab-list-actions .btn {
  padding: 0.25rem 0.5rem;
  font-size: 1rem;
  line-height: 1.5;
}

/* Compact Vocabulary Container */
.vocabulary-container {
  padding: 0;
  max-width: 100%;
  background: #f8f9fa;
  min-height: 100vh;
}

/* Compact Header - Matching content-header style */
.vocab-compact-header {
  background: linear-gradient(135deg, #f8fafc 0%, #e2e8f0 100%);
  color: #1e293b;
  padding: 1rem 1.25rem;
  position: sticky;
  top: 0;
  z-index: 100;
  box-shadow: 0 10px 40px rgba(0, 0, 0, 0.08);
  border-radius: 0 0 20px 20px;
  backdrop-filter: blur(20px);
  margin-bottom: 0;
  border: 1px solid rgba(255, 255, 255, 0.8);
  overflow: hidden;
}

.vocab-compact-header::before {
  content: "";
  position: absolute;
  top: -20%;
  right: -10%;
  width: 80px;
  height: 80px;
  background: linear-gradient(
    135deg,
    rgba(99, 102, 241, 0.1) 0%,
    rgba(139, 92, 246, 0.1) 100%
  );
  border-radius: 50%;
  animation: float 6s ease-in-out infinite;
}

.vocab-compact-header::after {
  content: "";
  position: absolute;
  bottom: -15%;
  left: -5%;
  width: 60px;
  height: 60px;
  background: linear-gradient(
    135deg,
    rgba(59, 130, 246, 0.08) 0%,
    rgba(16, 185, 129, 0.08) 100%
  );
  border-radius: 50%;
  animation: float 8s ease-in-out infinite reverse;
}

.header-top {
  display: flex;
  justify-content: space-between;
  align-items: center;
  margin-bottom: 1rem;
}

.title-section {
  display: flex;
  align-items: center;
  gap: 1rem;
}

.vocab-title {
  font-size: 1.4rem;
  font-weight: 700;
  margin: 0;
  display: flex;
  align-items: center;
  gap: 0.5rem;
  color: #1e293b;
}

.vocab-title i {
  font-size: 1.6rem;
  color: #6366f1;
}

.vocab-count {
  background: rgba(99, 102, 241, 0.1);
  color: #6366f1;
  padding: 0.4rem 1rem;
  border-radius: 20px;
  font-size: 0.85rem;
  font-weight: 600;
  backdrop-filter: blur(15px);
  border: 1px solid rgba(99, 102, 241, 0.2);
  box-shadow: 0 2px 8px rgba(0, 0, 0, 0.1);
}

.tab-switcher {
  display: flex;
  background: rgba(255, 255, 255, 0.2);
  border-radius: 16px;
  padding: 0.3rem;
  backdrop-filter: blur(15px);
  border: 1px solid rgba(255, 255, 255, 0.2);
  box-shadow: 0 2px 8px rgba(0, 0, 0, 0.1);
  position: relative;
  z-index: 20;
}

.tab-switch {
  display: flex;
  align-items: center;
  gap: 0.5rem;
  padding: 0.6rem 1.2rem;
  border: none;
  background: transparent;
  color: #1e293b;
  border-radius: 12px;
  font-size: 0.9rem;
  font-weight: 600;
  cursor: pointer;
  transition: all 0.3s cubic-bezier(0.4, 0, 0.2, 1);
}

.tab-switch.active {
  background: rgba(255, 255, 255, 0.95);
  color: #667eea;
  box-shadow: 0 4px 12px rgba(0, 0, 0, 0.15);
  transform: translateY(-1px);
}

.tab-switch:hover:not(.active) {
  background: rgba(99, 102, 241, 0.1);
  color: #6366f1;
}

.tab-switch i {
  font-size: 1rem;
}

.search-bar {
  margin-top: 1rem;
}

.search-wrapper {
  position: relative;
  display: flex;
  align-items: center;
  background: rgba(255, 255, 255, 0.95);
  border-radius: 20px;
  border: 2px solid rgba(0, 0, 0, 0.1);
  transition: all 0.3s cubic-bezier(0.4, 0, 0.2, 1);
  box-shadow: 0 4px 12px rgba(0, 0, 0, 0.1);
  backdrop-filter: blur(15px);
}

.search-wrapper:focus-within {
  border-color: #3b82f6;
  background: rgba(255, 255, 255, 1);
  box-shadow: 0 6px 20px rgba(59, 130, 246, 0.2);
  transform: translateY(-1px);
}

.search-wrapper i {
  position: absolute;
  left: 1rem;
  color: #6b7280;
  font-size: 1rem;
  z-index: 2;
}

.search-wrapper input {
  flex: 1;
  border: none;
  outline: none;
  padding: 0.875rem 1rem 0.875rem 2.5rem;
  background: transparent;
  font-size: 0.95rem;
  color: #374151;
  border-radius: 20px;
}

.search-wrapper input::placeholder {
  color: #9ca3af;
}

.search-clear {
  position: absolute;
  right: 0.75rem;
  background: none;
  border: none;
  color: rgba(255, 255, 255, 0.8);
  font-size: 1.1rem;
  cursor: pointer;
  padding: 0.4rem;
  border-radius: 50%;
  transition: all 0.3s cubic-bezier(0.4, 0, 0.2, 1);
  width: 32px;
  height: 32px;
  display: flex;
  align-items: center;
  justify-content: center;
}

.search-clear:hover {
  color: white;
  background: rgba(255, 255, 255, 0.2);
  transform: scale(1.1);
}

/* Compact Content Layout */
.vocab-content-compact {
  display: flex;
  flex-direction: column;
  gap: 0.75rem;
}

.japanese-row,
.vietnamese-row {
  display: flex;
  align-items: center;
  gap: 0.75rem;
}

.flag-container {
  width: 32px;
  height: 32px;
  display: flex;
  align-items: center;
  justify-content: center;
  background: #f8f9fa;
  border-radius: 8px;
  border: 1px solid #e9ecef;
  flex-shrink: 0;
}

.flag-emoji {
  font-size: 1.2rem;
  filter: drop-shadow(0 1px 2px rgba(0, 0, 0, 0.1));
}

.text-content {
  flex: 1;
  min-width: 0;
}

.japanese-text {
  font-size: 1.2rem;
  font-weight: 700;
  color: #1a202c;
  line-height: 1.4;
  word-break: break-all;
  letter-spacing: 0.5px;
}

.vietnamese-text {
  font-size: 1rem;
  font-weight: 600;
  color: #495057;
  line-height: 1.5;
  word-break: break-word;
}

/* Content Area */
.vocab-content {
  padding: 0;
  margin-top: 1rem;
}

.tab-pane {
  display: none;
  position: relative;
  z-index: 5;
}

.tab-pane.active {
  display: block;
}

/* Desktop Table */
.desktop-table {
  background: white;
  border-radius: 20px;
  margin: 1rem;
  overflow: hidden;
  box-shadow: 0 4px 20px rgba(0, 0, 0, 0.08);
}

.vocab-table {
  width: 100%;
  border-collapse: collapse;
}

.vocab-table th {
  background: linear-gradient(135deg, #f8f9fa 0%, #e9ecef 100%);
  padding: 1.25rem 1rem;
  text-align: left;
  font-weight: 600;
  color: #495057;
  border-bottom: 1px solid #e9ecef;
  font-size: 0.9rem;
  text-transform: uppercase;
  letter-spacing: 0.5px;
}

.vocab-table td {
  padding: 1.25rem 1rem;
  border-bottom: 1px solid #f1f3f4;
  vertical-align: middle;
  transition: all 0.2s ease;
}

.vocab-table tr:hover {
  background: linear-gradient(135deg, #f8f9fa 0%, #e9ecef 100%);
  transform: translateY(-1px);
  box-shadow: 0 2px 8px rgba(0, 0, 0, 0.05);
}

/* Mobile Cards */
.mobile-cards {
  padding: 1rem;
}

/* Load More Trigger */
.load-more-trigger {
  height: 20px;
  margin: 1rem 0;
}

/* Loading State */
.loading-state {
  text-align: center;
  padding: 2rem 1rem;
  color: #6c757d;
}

.loading-spinner {
  width: 32px;
  height: 32px;
  border: 3px solid #e9ecef;
  border-top: 3px solid #667eea;
  border-radius: 50%;
  animation: spin 1s linear infinite;
  margin: 0 auto 1rem;
}

.loading-state p {
  margin: 0;
  font-size: 0.9rem;
}

/* Empty State */
.empty-state {
  text-align: center;
  padding: 3rem 1rem;
  color: #6c757d;
}

.empty-state i {
  font-size: 2.5rem;
  color: #adb5bd;
  margin-bottom: 1rem;
}

.empty-state h3 {
  font-size: 1.2rem;
  font-weight: 600;
  margin-bottom: 0.5rem;
  color: #495057;
}

.empty-state p {
  font-size: 0.9rem;
  color: #6c757d;
  margin: 0;
}

.vocab-header-section::before {
  content: "";
  position: absolute;
  top: -50%;
  right: -20%;
  width: 200px;
  height: 200px;
  background: radial-gradient(
    circle,
    rgba(255, 255, 255, 0.1) 0%,
    transparent 70%
  );
  border-radius: 50%;
  animation: float 6s ease-in-out infinite;
}

.vocab-header-content {
  display: flex;
  justify-content: space-between;
  align-items: center;
  position: relative;
  z-index: 2;
}

.vocab-title-section {
  flex: 1;
}

.vocab-main-title {
  font-size: 1.8rem;
  font-weight: 800;
  margin-bottom: 0.5rem;
  display: flex;
  align-items: center;
  text-shadow: 0 2px 4px rgba(0, 0, 0, 0.1);
}

.vocab-main-title i {
  font-size: 2rem;
  margin-right: 0.75rem;
  filter: drop-shadow(0 2px 4px rgba(0, 0, 0, 0.1));
}

.vocab-subtitle {
  color: rgba(255, 255, 255, 0.85);
  font-size: 1rem;
  font-weight: 500;
  margin: 0;
  text-shadow: 0 1px 2px rgba(0, 0, 0, 0.1);
}

.vocab-stats {
  display: flex;
  gap: 1rem;
}

.stat-item {
  text-align: center;
  background: rgba(255, 255, 255, 0.15);
  padding: 1rem;
  border-radius: 16px;
  backdrop-filter: blur(10px);
  border: 1px solid rgba(255, 255, 255, 0.2);
  min-width: 80px;
}

.stat-number {
  display: block;
  font-size: 2rem;
  font-weight: 800;
  color: white;
  text-shadow: 0 1px 2px rgba(0, 0, 0, 0.1);
}

.stat-label {
  display: block;
  font-size: 0.8rem;
  color: white !important;
  font-weight: 500;
  margin-top: 0.25rem;
}

/* Tab Navigation */
.vocab-tab-navigation {
  margin-bottom: 1.5rem;
  padding: 0 1rem;
}

/* Tab Content */
.tab-content {
  position: relative;
}

.tab-pane {
  display: none;
}

.tab-pane.active {
  display: block;
}

.tab-buttons {
  display: flex;
  background: #f8f9fa;
  border-radius: 16px;
  padding: 0.5rem;
  box-shadow: 0 4px 12px rgba(0, 0, 0, 0.05);
}

.tab-button {
  flex: 1;
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 0.5rem;
  padding: 0.875rem 1rem;
  border: none;
  background: transparent;
  border-radius: 12px;
  font-weight: 600;
  font-size: 0.9rem;
  color: #6c757d;
  transition: all 0.3s cubic-bezier(0.4, 0, 0.2, 1);
  cursor: pointer;
}

.tab-button.active {
  background: white;
  color: #0d6efd;
  box-shadow: 0 2px 8px rgba(13, 110, 253, 0.15);
  transform: translateY(-1px);
}

.tab-button:hover:not(.active) {
  color: #495057;
  background: rgba(255, 255, 255, 0.5);
}

.tab-button i {
  font-size: 1.1rem;
}

/* Search Section */
.vocab-search-section {
  padding: 0 1rem;
  margin-bottom: 1.5rem;
}

.search-container {
  max-width: 100%;
}

.search-input-wrapper {
  position: relative;
  display: flex;
  align-items: center;
  background: white;
  border-radius: 16px;
  box-shadow: 0 4px 12px rgba(0, 0, 0, 0.08);
  border: 2px solid #e9ecef;
  transition: all 0.3s ease;
}

.search-input-wrapper:focus-within {
  border-color: #0d6efd;
  box-shadow: 0 4px 20px rgba(13, 110, 253, 0.15);
}

.search-icon {
  position: absolute;
  left: 1rem;
  color: #6c757d;
  font-size: 1.1rem;
  z-index: 2;
}

.search-input {
  flex: 1;
  border: none;
  outline: none;
  padding: 1rem 1rem 1rem 3rem;
  font-size: 1rem;
  background: transparent;
  color: #495057;
}

.search-input::placeholder {
  color: #adb5bd;
}

.search-clear-btn {
  position: absolute;
  right: 1rem;
  background: none;
  border: none;
  color: #6c757d;
  font-size: 1.2rem;
  cursor: pointer;
  padding: 0.25rem;
  border-radius: 50%;
  transition: all 0.2s ease;
}

.search-clear-btn:hover {
  color: #dc3545;
  background: rgba(220, 53, 69, 0.1);
}

/* Flashcard Controls Section - MOVED TO flashcard-style.css */

/* Modern Vocabulary Cards */
.vocab-card-modern {
  margin-bottom: 1.5rem;
  animation: slideInUp 0.6s ease forwards;
  opacity: 0;
  transform: translateY(20px);
}

@keyframes slideInUp {
  to {
    opacity: 1;
    transform: translateY(0);
  }
}

.vocab-card-content {
  background: white;
  border-radius: 20px;
  padding: 1.5rem;
  box-shadow: 0 8px 25px rgba(0, 0, 0, 0.08);
  border: 1px solid #e9ecef;
  transition: all 0.3s cubic-bezier(0.4, 0, 0.2, 1);
  position: relative;
  overflow: hidden;
}

.vocab-card-content::before {
  content: "";
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  height: 4px;
  background: linear-gradient(90deg, #667eea 0%, #764ba2 100%);
}

.vocab-card-content:hover {
  transform: translateY(-4px);
  box-shadow: 0 12px 35px rgba(0, 0, 0, 0.12);
  border-color: #0d6efd;
}

.vocab-header {
  display: flex;
  justify-content: space-between;
  align-items: center;
  margin-bottom: 1.5rem;
}

.vocab-number {
  background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
  color: white;
  width: 32px;
  height: 32px;
  border-radius: 50%;
  display: flex;
  align-items: center;
  justify-content: center;
  font-weight: 700;
  font-size: 0.9rem;
  box-shadow: 0 4px 12px rgba(102, 126, 234, 0.3);
}

.vocab-actions {
  display: flex;
  gap: 0.5rem;
}

.action-btn {
  width: 40px;
  height: 40px;
  border: none;
  border-radius: 12px;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 1.1rem;
  cursor: pointer;
  transition: all 0.3s cubic-bezier(0.4, 0, 0.2, 1);
  box-shadow: 0 2px 8px rgba(0, 0, 0, 0.1);
}

.speak-btn {
  background: linear-gradient(135deg, #4facfe 0%, #00f2fe 100%);
  color: white;
}

.explanation-btn {
  background: linear-gradient(135deg, #43e97b 0%, #38f9d7 100%);
  color: white;
}

.action-btn:hover {
  transform: scale(1.1) translateY(-2px);
  box-shadow: 0 6px 20px rgba(0, 0, 0, 0.2);
}

.vocab-main {
  display: flex;
  flex-direction: column;
  gap: 1rem;
}

.japanese-section,
.vietnamese-section {
  flex: 1;
}

.japanese-text {
  font-size: 1.4rem;
  font-weight: 700;
  color: #1a202c;
  line-height: 1.4;
  word-break: break-all;
  letter-spacing: 0.5px;
}

.vietnamese-text {
  font-size: 1.1rem;
  font-weight: 600;
  color: #495057;
  line-height: 1.5;
  word-break: break-word;
}

.divider {
  display: flex;
  justify-content: center;
  align-items: center;
  margin: 0.5rem 0;
}

.divider i {
  color: #adb5bd;
  font-size: 1.2rem;
  background: #f8f9fa;
  padding: 0.5rem;
  border-radius: 50%;
  border: 2px solid #e9ecef;
}

/* Loader and Empty State */
.vocab-loader {
  text-align: center;
  padding: 3rem 1rem;
}

.loader-content {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 1rem;
}

.spinner {
  width: 40px;
  height: 40px;
  border: 4px solid #e9ecef;
  border-top: 4px solid #0d6efd;
  border-radius: 50%;
  animation: spin 1s linear infinite;
}

@keyframes spin {
  0% {
    transform: rotate(0deg);
  }
  100% {
    transform: rotate(360deg);
  }
}

.vocab-empty-state {
  text-align: center;
  padding: 3rem 1rem;
  color: #6c757d;
}

.empty-icon {
  font-size: 3rem;
  color: #adb5bd;
  margin-bottom: 1rem;
}

.vocab-empty-state h3 {
  font-size: 1.3rem;
  font-weight: 600;
  margin-bottom: 0.5rem;
  color: #495057;
}

.vocab-empty-state p {
  font-size: 1rem;
  color: #6c757d;
}

/* Dark Mode Styles */
[data-bs-theme="dark"] .vocabulary-container {
  background: #1a202c;
}

[data-bs-theme="dark"] .vocab-compact-header {
  background: linear-gradient(135deg, #1e293b 0%, #0f172a 100%);
  color: #f1f5f9;
  border-color: #334155;
}

[data-bs-theme="dark"] .vocab-compact-header::before {
  background: linear-gradient(
    135deg,
    rgba(99, 102, 241, 0.15) 0%,
    rgba(139, 92, 246, 0.15) 100%
  );
}

[data-bs-theme="dark"] .vocab-compact-header::after {
  background: linear-gradient(
    135deg,
    rgba(59, 130, 246, 0.12) 0%,
    rgba(16, 185, 129, 0.12) 100%
  );
}

[data-bs-theme="dark"] .vocab-title {
  color: #f1f5f9;
}

[data-bs-theme="dark"] .vocab-title i {
  color: #818cf8;
}

[data-bs-theme="dark"] .vocab-count {
  background: rgba(129, 140, 248, 0.15);
  color: #818cf8;
  border: 1px solid rgba(129, 140, 248, 0.3);
}

[data-bs-theme="dark"] .tab-switcher {
  background: rgba(255, 255, 255, 0.15);
  border: 1px solid rgba(255, 255, 255, 0.1);
}

[data-bs-theme="dark"] .tab-switch {
  color: #e2e8f0;
}

[data-bs-theme="dark"] .tab-switch.active {
  background: rgba(255, 255, 255, 0.95);
  color: #4a5568;
}

[data-bs-theme="dark"] .tab-switch:hover:not(.active) {
  background: rgba(129, 140, 248, 0.15);
  color: #818cf8;
}

[data-bs-theme="dark"] .search-wrapper {
  background: rgba(255, 255, 255, 0.1);
}

[data-bs-theme="dark"] .search-wrapper:focus-within {
  border-color: rgba(255, 255, 255, 0.3);
  background: rgba(255, 255, 255, 0.15);
}

[data-bs-theme="dark"] .search-wrapper i {
  color: rgba(255, 255, 255, 0.7);
}

[data-bs-theme="dark"] .search-wrapper input {
  color: #e2e8f0;
}

[data-bs-theme="dark"] .search-wrapper input::placeholder {
  color: rgba(255, 255, 255, 0.5);
}

[data-bs-theme="dark"] .search-clear {
  color: rgba(255, 255, 255, 0.7);
}

[data-bs-theme="dark"] .search-clear:hover {
  color: white;
  background: rgba(255, 255, 255, 0.15);
}

[data-bs-theme="dark"] .desktop-table {
  background: #2d3748;
  box-shadow: 0 4px 20px rgba(0, 0, 0, 0.3);
  border-radius: 20px;
}

[data-bs-theme="dark"] .vocab-table th {
  background: linear-gradient(135deg, #4a5568 0%, #718096 100%);
  color: #e2e8f0;
  border-bottom-color: #718096;
}

[data-bs-theme="dark"] .vocab-table td {
  color: #e2e8f0;
  border-bottom-color: #4a5568;
}

[data-bs-theme="dark"] .vocab-table tr:hover {
  background: linear-gradient(135deg, #4a5568 0%, #718096 100%);
  transform: translateY(-1px);
  box-shadow: 0 2px 8px rgba(0, 0, 0, 0.2);
}

[data-bs-theme="dark"] .loading-state {
  color: #a0aec0;
}

[data-bs-theme="dark"] .loading-spinner {
  border-color: #4a5568;
  border-top-color: #60a5fa;
}

[data-bs-theme="dark"] .empty-state {
  color: #a0aec0;
}

[data-bs-theme="dark"] .empty-state i {
  color: #718096;
}

[data-bs-theme="dark"] .empty-state h3 {
  color: #e2e8f0;
}

[data-bs-theme="dark"] .empty-state p {
  color: #a0aec0;
}

[data-bs-theme="dark"] .flag-container {
  background: #4a5568;
  border-color: #718096;
}

/* Dark mode flashcard controls - MOVED TO flashcard-style.css */

[data-bs-theme="dark"] .vocab-header-section::before {
  background: radial-gradient(
    circle,
    rgba(255, 255, 255, 0.05) 0%,
    transparent 70%
  );
}

[data-bs-theme="dark"] .stat-item {
  background: rgba(255, 255, 255, 0.1);
  border-color: rgba(255, 255, 255, 0.15);
}

[data-bs-theme="dark"] .tab-buttons {
  background: #2d3748;
}

[data-bs-theme="dark"] .tab-button {
  color: #a0aec0;
}

[data-bs-theme="dark"] .tab-button.active {
  background: #4a5568;
  color: #60a5fa;
}

[data-bs-theme="dark"] .tab-button:hover:not(.active) {
  color: #e2e8f0;
  background: rgba(255, 255, 255, 0.1);
}

[data-bs-theme="dark"] .search-input-wrapper {
  background: #2d3748;
  border-color: #4a5568;
}

[data-bs-theme="dark"] .search-input-wrapper:focus-within {
  border-color: #60a5fa;
  box-shadow: 0 4px 20px rgba(96, 165, 250, 0.15);
}

[data-bs-theme="dark"] .search-input {
  color: #e2e8f0;
}

[data-bs-theme="dark"] .search-input::placeholder {
  color: #a0aec0;
}

[data-bs-theme="dark"] .search-icon {
  color: #a0aec0;
}

[data-bs-theme="dark"] .search-clear-btn {
  color: #a0aec0;
}

[data-bs-theme="dark"] .search-clear-btn:hover {
  color: #fc8181;
  background: rgba(252, 129, 129, 0.1);
}

[data-bs-theme="dark"] .mode-toggle-container {
  background: linear-gradient(135deg, #374151 0%, #1f2937 100%);
  border: 2px solid #4b5563;
}

[data-bs-theme="dark"] .mode-toggle-btn {
  color: #cbd5e0;
}

[data-bs-theme="dark"] .mode-toggle-btn.active {
  background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
  color: white;
  box-shadow: 0 4px 15px rgba(102, 126, 234, 0.4);
}

[data-bs-theme="dark"] .mode-toggle-btn:hover:not(.active) {
  color: #f7fafc;
  background: rgba(102, 126, 234, 0.2);
}

[data-bs-theme="dark"] .vocab-card-content {
  background: #2d3748;
  border-color: #4a5568;
}

[data-bs-theme="dark"] .vocab-card-content:hover {
  border-color: #60a5fa;
  box-shadow: 0 12px 35px rgba(96, 165, 250, 0.15);
}

[data-bs-theme="dark"] .japanese-text {
  color: #f7fafc;
}

[data-bs-theme="dark"] .vietnamese-text {
  color: #e2e8f0;
}

[data-bs-theme="dark"] .divider i {
  color: #a0aec0;
  background: #4a5568;
  border-color: #718096;
}

[data-bs-theme="dark"] .vocab-empty-state {
  color: #a0aec0;
}

[data-bs-theme="dark"] .vocab-empty-state h3 {
  color: #e2e8f0;
}

[data-bs-theme="dark"] .vocab-empty-state p {
  color: #a0aec0;
}

[data-bs-theme="dark"] .empty-icon {
  color: #718096;
}

/* Legacy dark mode styles for old mobile cards */
[data-bs-theme="dark"] .vocab-mobile-card .card {
  background-color: #2d3748;
  border-color: #4a5568;
}

[data-bs-theme="dark"] .vocab-mobile-card .card:hover {
  border-color: #60a5fa;
  box-shadow: 0 6px 20px rgba(96, 165, 250, 0.2) !important;
}

[data-bs-theme="dark"] .vocab-japanese .japanese-text {
  color: #f7fafc;
}

[data-bs-theme="dark"] .vocab-vietnamese {
  background: #1a202c;
  border-left-color: #60a5fa;
}

[data-bs-theme="dark"] .vocab-vietnamese .vietnamese-text {
  color: #e2e8f0;
}

[data-bs-theme="dark"] .vocab-actions .btn {
  background-color: #4a5568;
  border-color: #718096;
  color: #e2e8f0;
}

[data-bs-theme="dark"] .vocab-actions .btn:hover {
  background-color: #60a5fa;
  border-color: #60a5fa;
  color: #ffffff;
}
.list-group-item.correct {
  background-color: #d1e7dd !important;
  border-color: #badbcc !important;
  color: #0f5132 !important;
}
.list-group-item.incorrect {
  background-color: #f8d7da !important;
  border-color: #f5c2c7 !important;
  color: #842029 !important;
  text-decoration: line-through;
}
.list-group-item.no-answer-correct {
  background-color: #cff4fc !important;
  border-color: #b6effb !important;
  color: #055160 !important;
}

.document-content img {
  max-width: 100%;
  height: auto;
  border-radius: 8px;
  margin-top: 1rem;
  margin-bottom: 1rem;
}

.quiz-controls-container {
  position: fixed;
  top: calc(var(--top-header-height) + 10px);
  right: 15px;
  z-index: 1025;
  display: none;
  flex-direction: column;
  align-items: flex-end;
  gap: 10px;
}
.fixed-quiz-control {
  display: none;
}
#fixed-quiz-timer {
  background-color: rgba(0, 0, 0, 0.7);
  color: white;
  padding: 8px 15px;
  border-radius: 20px;
  font-size: 1.1rem;
  font-weight: bold;
  display: flex;
  align-items: center;
  transition: background-color 0.3s ease;
}
#fixed-quiz-timer::before {
  font-family: "bootstrap-icons";
  content: "\F282";
  margin-right: 8px;
  font-size: 1.2rem;
}
#fixed-quiz-submit {
  background-color: rgba(0, 0, 0, 0.7);
  color: white;
  padding: 8px 15px;
  border-radius: 20px;
  font-size: 1.1rem;
  font-weight: bold;
  border: none;
  cursor: pointer;
  transition: background-color 0.3s ease;
}

.question-image {
  max-width: 100%;
  max-height: 300px;
  width: auto;
  height: auto;
  border-radius: 8px;
  border: 1px solid #dee2e6;
  margin-bottom: 1rem;
  object-fit: contain;
  display: block;
  margin-left: auto;
  margin-right: auto;
}

/* Responsive adjustments for question images */
@media (max-width: 768px) {
  .question-image {
    max-height: 250px;
  }
}

@media (max-width: 480px) {
  .question-image {
    max-height: 200px;
  }
}

/* --- Dark Mode Styles --- */
[data-bs-theme="dark"] html,
[data-bs-theme="dark"] body {
  background-color: #121212 !important;
  color: #dee2e6;
  min-height: 100vh;
}

[data-bs-theme="dark"] body {
  background-color: #121212 !important;
  color: #dee2e6;
}
[data-bs-theme="dark"] .top-header,
[data-bs-theme="dark"] .bottom-nav {
  background: linear-gradient(135deg, #1c1c1c 0%, #2d2d2d 100%);
  border-color: #3d3d3d;
}

[data-bs-theme="dark"] .bottom-nav {
  border-top: 1px solid rgba(255, 255, 255, 0.1);
  box-shadow: 0 -4px 20px rgba(0, 0, 0, 0.4);
  backdrop-filter: blur(10px);
}

/* Remove any white lines or borders in dark mode */
[data-bs-theme="dark"] * {
  border-color: #3d3d3d !important;
}

[data-bs-theme="dark"] .bottom-nav a {
  color: #8e8e93;
}

[data-bs-theme="dark"] .bottom-nav a.active {
  color: #ffffff;
}

[data-bs-theme="dark"] .bottom-nav a:hover:not(.active) {
  color: #60a5fa;
}
[data-bs-theme="dark"] .btn-dark-mode {
  color: #adb5bd;
}
[data-bs-theme="dark"] .card,
[data-bs-theme="dark"] .modal-content,
[data-bs-theme="dark"] .list-group-item,
[data-bs-theme="dark"] .offcanvas {
  background-color: #1e1e1e !important;
  border-color: #2d2d2d !important;
  color: #dee2e6;
}

/* Dark mode for dashboard container */
[data-bs-theme="dark"] .dashboard-container {
  background-color: #121212;
}

/* Dark mode for main content */
[data-bs-theme="dark"] .main-content {
  background-color: #121212;
}

/* Dark mode for section headers */
[data-bs-theme="dark"] .section-header {
  background-color: #121212;
}

/* Dark mode for progress section */
[data-bs-theme="dark"] .progress-section {
  background-color: #121212;
}

[data-bs-theme="dark"] .progress-section .card {
  background-color: #1e1e1e;
  border-color: #2d2d2d;
}

[data-bs-theme="dark"] .progress-section .card-header {
  background: linear-gradient(135deg, #4a5568 0%, #2d3748 100%);
}

[data-bs-theme="dark"] .progress-item {
  border-bottom-color: #2d2d2d;
}

[data-bs-theme="dark"] .progress-label {
  color: #e2e8f0;
}

[data-bs-theme="dark"] .progress-value {
  color: #90cdf4;
}

[data-bs-theme="dark"] .progress-bar-custom {
  background-color: #2d2d2d;
}

/* Dark mode for actions section */
[data-bs-theme="dark"] .actions-section {
  background-color: #121212;
}

[data-bs-theme="dark"] .actions-section .card {
  background-color: #1e1e1e;
  border-color: #2d2d2d;
}

[data-bs-theme="dark"] .actions-section .card-header {
  background: linear-gradient(135deg, #2d5a27 0%, #1a3d1a 100%);
}

[data-bs-theme="dark"] .action-item {
  background-color: #1e1e1e;
  border-color: #2d2d2d;
}

[data-bs-theme="dark"] .action-item:hover {
  background-color: #2d2d2d;
  border-color: #4a5568;
}

[data-bs-theme="dark"] .action-title {
  color: #e2e8f0;
}

[data-bs-theme="dark"] .action-description {
  color: #a0aec0;
}
[data-bs-theme="dark"] #chat-output {
  background-color: #121212;
}

/* Ensure all main containers have consistent dark background */
[data-bs-theme="dark"] .container,
[data-bs-theme="dark"] .container-fluid,
[data-bs-theme="dark"] .row,
[data-bs-theme="dark"] .col,
[data-bs-theme="dark"] .col-* {
  background-color: transparent;
}

/* Fix any potential white backgrounds in dark mode */
[data-bs-theme="dark"] .bg-white,
[data-bs-theme="dark"] .bg-light {
  background-color: #1e1e1e !important;
}

/* Ensure consistent background for all main page elements */
[data-bs-theme="dark"] .page-wrapper,
[data-bs-theme="dark"] .app-container,
[data-bs-theme="dark"] .main-wrapper {
  background-color: #121212 !important;
}

/* Dark mode for flashcard - MOVED TO flashcard-style.css */

[data-bs-theme="dark"] .list-group-item.correct {
  background-color: #0f5132 !important;
  border-color: #0f5132 !important;
  color: #fff !important;
}
[data-bs-theme="dark"] .list-group-item.incorrect {
  background-color: #842029 !important;
  border-color: #842029 !important;
  color: #fff !important;
}
[data-bs-theme="dark"] .list-group-item.no-answer-correct {
  background-color: #032830 !important;
  border-color: #032830 !important;
  color: #9eeaf9 !important;
}
/* Dark Mode AI Chat */
[data-bs-theme="dark"] #ai-chat-modal .modal-content {
  background: linear-gradient(135deg, #1c1c1c 0%, #2d2d2d 100%);
}

[data-bs-theme="dark"] .chat-header {
  background: linear-gradient(135deg, #4a5568 0%, #2d3748 100%);
}

[data-bs-theme="dark"] .chat-body {
  background: linear-gradient(135deg, #2d2d2d 0%, #1c1c1c 100%);
}

[data-bs-theme="dark"] .chat-footer {
  background: linear-gradient(135deg, #1c1c1c 0%, #2d2d2d 100%);
  border-color: #3d3d3d;
}

[data-bs-theme="dark"] .chat-input-bar {
  background: #2d2d2d;
  border: 1px solid rgba(102, 126, 234, 0.2);
}

[data-bs-theme="dark"] .chat-input-bar .form-control {
  background: transparent;
  color: #dee2e6;
}

[data-bs-theme="dark"] .chat-input-bar .form-control::placeholder {
  color: #8e8e93;
}

[data-bs-theme="dark"] .ai-bubble {
  background: linear-gradient(135deg, #2d2d2d 0%, #3d3d3d 100%);
  color: #dee2e6;
  border: 1px solid rgba(102, 126, 234, 0.2);
}

[data-bs-theme="dark"] .ai-bubble::before {
  border-right-color: #2d2d2d;
}

[data-bs-theme="dark"] .user-bubble {
  background: linear-gradient(135deg, #4a5568 0%, #2d3748 100%);
  color: white;
}

[data-bs-theme="dark"] .user-bubble::before {
  border-left-color: #2d3748;
}

[data-bs-theme="dark"] .ai-avatar {
  background: linear-gradient(135deg, #4a5568 0%, #2d3748 100%);
  color: white;
}

[data-bs-theme="dark"] .typing-indicator {
  background: linear-gradient(135deg, #2d2d2d 0%, #3d3d3d 100%);
  border: 1px solid rgba(102, 126, 234, 0.2);
}

[data-bs-theme="dark"] #chat-output::-webkit-scrollbar-track {
  background: #2d2d2d;
}

[data-bs-theme="dark"] #chat-output::-webkit-scrollbar-thumb {
  background: linear-gradient(135deg, #4a5568, #2d3748);
}
[data-bs-theme="dark"] .user-profile .user-avatar {
  border-color: #495057;
}
[data-bs-theme="dark"] .user-profile a:hover .user-avatar {
  border-color: var(--primary-color);
}
[data-bs-theme="dark"] .suggestion-chip {
  background-color: transparent;
  border-color: #495057;
  color: #adb5bd;
}
[data-bs-theme="dark"] .suggestion-chip:hover {
  background-color: #0d6efd;
  border-color: #0d6efd;
  color: #ffffff;
}
[data-bs-theme="dark"] .question-image {
  border-color: #495057;
}
[data-bs-theme="dark"] .srs-btn:hover {
  transform: scale(1.05);
  opacity: 0.8;
}
[data-bs-theme="dark"] .vocab-list-actions .btn {
  --bs-btn-color: #adb5bd;
  --bs-btn-border-color: #495057;
  --bs-btn-hover-color: #fff;
  --bs-btn-hover-bg: #495057;
  --bs-btn-hover-border-color: #495057;
}

@keyframes slideInUp {
  from {
    transform: translateY(30px);
    opacity: 0;
  }
  to {
    transform: translateY(0);
    opacity: 1;
  }
}
.animate-in {
  animation: slideInUp 0.4s ease-out;
}
:focus-visible {
  outline: 3px solid var(--primary-color);
  outline-offset: 2px;
}
@media (pointer: coarse) {
  .btn,
  .list-group-item,
  .nav-link {
    min-height: 44px;
    display: flex;
    align-items: center;
  }
}
/**
 * ============================================
 * DDL-MOD: GIAO DIỆN DASHBOARD TRANG CHỦ
 * ============================================
 */
.dashboard-header h2 {
  font-weight: 600;
}
.stat-card {
  background-color: #fff;
  border-radius: 12px;
  padding: 1.25rem;
  display: flex;
  align-items: center;
  gap: 1rem;
  border: 1px solid #e9ecef;
  transition: transform 0.2s ease, box-shadow 0.2s ease;
}
.stat-card:hover {
  transform: translateY(-5px);
  box-shadow: 0 8px 20px rgba(0, 0, 0, 0.08);
}
.stat-card i {
  font-size: 2.5rem;
  padding: 1rem;
  background-color: var(--bs-light-bg-subtle);
  border-radius: 50%;
}
.stat-card-info {
  display: flex;
  flex-direction: column;
}
.stat-card-value {
  font-size: 2rem;
  font-weight: 700;
  line-height: 1.2;
}
.stat-card-label {
  font-size: 0.9rem;
  color: #6c757d;
}
.quick-actions .list-group-item {
  display: flex;
  align-items: center;
  gap: 1rem;
  padding: 1rem 1.25rem;
}
.quick-actions .list-group-item i:first-child {
  font-size: 1.5rem;
}
.quick-actions .list-group-item div {
  flex-grow: 1;
}

[data-bs-theme="dark"] .stat-card {
  background-color: #1e1e1e;
  border-color: #2d2d2d;
}
[data-bs-theme="dark"] .stat-card i {
  background-color: #2d2d2d;
}

/* Dark mode for stat icons */
[data-bs-theme="dark"] .stat-icon-mobile {
  background-color: #2d2d2d;
  color: #e9ecef;
}

[data-bs-theme="dark"] .stat-number-mobile {
  color: #f8f9fa;
}

[data-bs-theme="dark"] .stat-label-mobile {
  color: #adb5bd;
}

/* Dark mode for action icons */
[data-bs-theme="dark"] .action-icon-mobile {
  background-color: #2d2d2d;
  color: #e9ecef;
}

[data-bs-theme="dark"] .action-title-mobile {
  color: #f8f9fa;
}

[data-bs-theme="dark"] .action-description-mobile {
  color: #adb5bd;
}

/* Mobile responsive styles for progress and actions sections */
@media (max-width: 768px) {
  .progress-section .card,
  .actions-section .card {
    border-radius: 12px;
    margin-bottom: 1rem;
  }

  .progress-section .card-header,
  .actions-section .card-header {
    padding: 0.75rem 1rem;
    font-size: 0.9rem;
  }

  .progress-section .card-body,
  .actions-section .card-body {
    padding: 1rem;
  }

  .progress-item {
    padding: 0.5rem 0;
  }

  .progress-label {
    font-size: 0.9rem;
  }

  .progress-value {
    font-size: 0.9rem;
  }

  .action-item {
    padding: 0.75rem;
    margin-bottom: 0.5rem;
  }

  .action-icon {
    width: 40px;
    height: 40px;
    font-size: 1rem;
  }

  .action-title {
    font-size: 0.9rem;
  }

  .action-description {
    font-size: 0.8rem;
  }
}

/* Dark mode for form elements */
[data-bs-theme="dark"] .form-select {
  background-color: #343a40;
  border-color: #495057;
  color: #e9ecef;
}

[data-bs-theme="dark"] .form-select:focus {
  background-color: #343a40;
  border-color: #60a5fa;
  color: #e9ecef;
}

/* Dark mode for badges */
[data-bs-theme="dark"] .badge {
  background-color: #495057;
  color: #e9ecef;
}

/* ==================================================================== */
/* PRACTICE INTERFACE - MODERN DESIGN */
/* ==================================================================== */

.practice-container {
  padding: 0;
  max-width: 1200px;
  margin: 0 auto;
}

/* Practice Mode Cards */
.practice-mode-section {
  margin-bottom: 2rem;
}

.mode-cards {
  display: grid;
  grid-template-columns: 1fr;
  gap: 1rem;
}

.mode-card {
  background: #ffffff;
  border: 2px solid #e9ecef;
  border-radius: 16px;
  padding: 1.5rem;
  cursor: pointer;
  transition: all 0.3s ease;
  position: relative;
  overflow: hidden;
  display: flex;
  align-items: center;
  gap: 1rem;
}

.mode-card::before {
  content: "";
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  height: 4px;
  background: linear-gradient(90deg, #e9ecef, #dee2e6);
  transition: all 0.3s ease;
}

.mode-card:hover {
  transform: translateY(-2px);
  box-shadow: 0 8px 25px rgba(0, 0, 0, 0.1);
  border-color: #0d6efd;
}

.mode-card.active {
  border-color: #0d6efd;
  background: linear-gradient(135deg, #f8f9ff 0%, #e3f2fd 100%);
  box-shadow: 0 8px 25px rgba(13, 110, 253, 0.15);
}

.mode-card.active::before {
  background: linear-gradient(90deg, #0d6efd, #6f42c1);
}

.mode-icon {
  width: 60px;
  height: 60px;
  border-radius: 12px;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 1.5rem;
  color: #6c757d;
  background: #f8f9fa;
  transition: all 0.3s ease;
  flex-shrink: 0;
}

.mode-card.active .mode-icon {
  background: linear-gradient(135deg, #0d6efd, #6f42c1);
  color: #ffffff;
  transform: scale(1.1);
}

.mode-content {
  flex: 1;
}

.mode-title {
  font-size: 1.1rem;
  font-weight: 600;
  margin: 0 0 0.5rem 0;
  color: #212529;
}

.mode-description {
  font-size: 0.9rem;
  color: #6c757d;
  margin: 0;
}

.mode-badge {
  flex-shrink: 0;
}

.mode-badge .badge {
  font-size: 0.75rem;
  padding: 0.5rem 0.75rem;
  border-radius: 20px;
}

/* Setup Card */
.setup-card {
  background: #ffffff;
  border-radius: 20px;
  box-shadow: 0 4px 20px rgba(0, 0, 0, 0.08);
  overflow: hidden;
  border: 1px solid #e9ecef;
}

.setup-header {
  background: linear-gradient(135deg, #f8f9fa 0%, #e9ecef 100%);
  padding: 1.5rem;
  border-bottom: 1px solid #dee2e6;
}

.setup-title {
  font-size: 1.3rem;
  font-weight: 600;
  margin: 0;
  color: #495057;
  display: flex;
  align-items: center;
}

.setup-content {
  padding: 0;
}

.setup-section {
  margin-bottom: 1.5rem;
}

.form-group {
  margin-bottom: 0;
}

.form-label {
  font-weight: 600;
  color: #495057;
  margin-bottom: 0.75rem;
  display: flex;
  align-items: center;
  font-size: 1rem;
}

.select-wrapper {
  position: relative;
}

.form-select {
  border: 2px solid #e9ecef;
  border-radius: 12px;
  padding: 0.75rem 1rem;
  font-size: 1rem;
  background-color: #ffffff;
  transition: all 0.3s ease;
}

.form-select:focus {
  border-color: #0d6efd;
  box-shadow: 0 0 0 0.2rem rgba(13, 110, 253, 0.1);
}

.select-icon {
  position: absolute;
  right: 1rem;
  top: 50%;
  transform: translateY(-50%);
  color: #6c757d;
  pointer-events: none;
}

/* Info Cards */
.info-card {
  background: linear-gradient(135deg, #e3f2fd 0%, #f3e5f5 100%);
  border: 1px solid #bbdefb;
  border-radius: 12px;
  padding: 1.5rem;
  display: flex;
  align-items: flex-start;
  gap: 1rem;
}

.info-icon {
  width: 40px;
  height: 40px;
  border-radius: 8px;
  background: #0d6efd;
  color: #ffffff;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 1.2rem;
  flex-shrink: 0;
}

.info-content h5 {
  font-size: 1.1rem;
  font-weight: 600;
  margin: 0 0 0.5rem 0;
  color: #1976d2;
}

.info-content p {
  margin: 0;
  color: #424242;
  font-size: 0.95rem;
  line-height: 1.5;
}

/* Start Button */
.start-button-wrapper {
  margin-top: 2rem;
  text-align: center;
}

.btn-start {
  background: linear-gradient(135deg, #0d6efd 0%, #6f42c1 100%);
  border: none;
  border-radius: 16px;
  padding: 1rem 2rem;
  color: #ffffff;
  font-size: 1.1rem;
  font-weight: 600;
  display: inline-flex;
  align-items: center;
  gap: 0.75rem;
  cursor: pointer;
  transition: all 0.3s ease;
  box-shadow: 0 4px 15px rgba(13, 110, 253, 0.3);
  min-width: 200px;
  justify-content: center;
}

.btn-start:hover {
  transform: translateY(-2px);
  box-shadow: 0 8px 25px rgba(13, 110, 253, 0.4);
  background: linear-gradient(135deg, #0b5ed7 0%, #5a2d91 100%);
}

.btn-start:active {
  transform: translateY(0);
}

.btn-start i {
  font-size: 1.2rem;
}

/* Quiz Container */
.quiz-container {
  margin-top: 2rem;
}

/* =========================================================================
   LIBRARY MODERN STYLES
   ========================================================================= */

/* Library Container */
.library-container {
  padding: 0;
  max-width: 100%;
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto,
    "Helvetica Neue", Arial, sans-serif;
}

/* Library Header */
.library-header {
  background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
  color: white;
  padding: 2.5rem 2rem;
  border-radius: 20px;
  margin-bottom: 2.5rem;
  box-shadow: 0 12px 40px rgba(102, 126, 234, 0.25);
  position: relative;
  overflow: hidden;
}

.library-header::before {
  content: "";
  position: absolute;
  top: -50%;
  right: -20%;
  width: 200px;
  height: 200px;
  background: radial-gradient(
    circle,
    rgba(255, 255, 255, 0.1) 0%,
    transparent 70%
  );
  border-radius: 50%;
  animation: float 6s ease-in-out infinite;
}

.library-header::after {
  content: "";
  position: absolute;
  bottom: -30%;
  left: -10%;
  width: 150px;
  height: 150px;
  background: radial-gradient(
    circle,
    rgba(255, 255, 255, 0.08) 0%,
    transparent 70%
  );
  border-radius: 50%;
  animation: float 8s ease-in-out infinite reverse;
}

@keyframes float {
  0%,
  100% {
    transform: translateY(0px) rotate(0deg);
  }
  50% {
    transform: translateY(-20px) rotate(180deg);
  }
}

.library-title {
  display: flex;
  align-items: center;
  gap: 1rem;
  font-size: 1.75rem;
  font-weight: 800;
  margin-bottom: 1.5rem;
  position: relative;
  z-index: 2;
}

.library-title i {
  font-size: 2rem;
  opacity: 0.95;
  filter: drop-shadow(0 2px 4px rgba(0, 0, 0, 0.1));
}

.library-stats {
  display: flex;
  gap: 2rem;
  position: relative;
  z-index: 2;
}

.stat-item {
  display: flex;
  align-items: center;
  gap: 0.75rem;
  background: rgba(255, 255, 255, 0.2);
  padding: 0.75rem 1.5rem;
  border-radius: 25px;
  backdrop-filter: blur(15px);
  border: 1px solid rgba(255, 255, 255, 0.3);
  transition: all 0.3s ease;
  box-shadow: 0 4px 15px rgba(0, 0, 0, 0.1);
}

.stat-item:hover {
  background: rgba(255, 255, 255, 0.25);
  transform: translateY(-2px);
  box-shadow: 0 6px 20px rgba(0, 0, 0, 0.15);
}

.stat-item i {
  font-size: 1.25rem;
  opacity: 0.95;
  filter: drop-shadow(0 1px 2px rgba(0, 0, 0, 0.1));
}

.stat-item span {
  font-weight: 700;
  font-size: 1rem;
  text-shadow: 0 1px 2px rgba(0, 0, 0, 0.1);
}

/* Unified Content Section */
.unified-content-section {
  margin-bottom: 2rem;
  margin-top: 1rem;
}

.content-header {
  display: flex;
  flex-direction: column;
  gap: 2rem;
  margin-bottom: 0;
  padding: 3rem 2.5rem;
  background: linear-gradient(135deg, #f8fafc 0%, #e2e8f0 100%);
  border-radius: 24px;
  box-shadow: 0 10px 40px rgba(0, 0, 0, 0.08);
  border: 1px solid rgba(255, 255, 255, 0.8);
  position: relative;
  overflow: hidden;
  backdrop-filter: blur(20px);
}

/* Sticky Search and Filter Section */
.content-search-filter-section {
  position: sticky;
  top: var(--top-header-height);
  z-index: 1000;
  background: linear-gradient(135deg, #f8fafc 0%, #e2e8f0 100%);
  border-radius: 16px;
  padding: 0.75rem 1rem;
  margin: 0.25rem 0;
  box-shadow: 0 4px 20px rgba(0, 0, 0, 0.1);
  border: 1px solid rgba(255, 255, 255, 0.8);
  backdrop-filter: blur(20px);
  will-change: transform;
  transform: translateZ(0);
  display: flex;
  align-items: center;
  gap: 0.75rem;
}

.library-search-section {
  flex: 1;
  min-width: 200px;
}

.content-filters {
  display: flex;
  gap: 0.375rem;
  flex-shrink: 0;
}

.content-header::before {
  content: "";
  position: absolute;
  top: -20%;
  right: -10%;
  width: 120px;
  height: 120px;
  background: linear-gradient(
    135deg,
    rgba(99, 102, 241, 0.1) 0%,
    rgba(139, 92, 246, 0.1) 100%
  );
  border-radius: 50%;
  animation: float 6s ease-in-out infinite;
}

.content-header::after {
  content: "";
  position: absolute;
  bottom: -15%;
  left: -5%;
  width: 80px;
  height: 80px;
  background: linear-gradient(
    135deg,
    rgba(59, 130, 246, 0.08) 0%,
    rgba(16, 185, 129, 0.08) 100%
  );
  border-radius: 50%;
  animation: float 8s ease-in-out infinite reverse;
}

.content-title-wrapper {
  position: relative;
  z-index: 2;
  text-align: center;
}

.content-section-title {
  font-size: 2.5rem;
  font-weight: 800;
  color: #0f172a;
  margin-bottom: 1rem;
  letter-spacing: -0.025em;
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 1rem;
}

.content-section-title i {
  font-size: 2rem;
  color: #dc2626;
  background: linear-gradient(135deg, #dc2626 0%, #ea580c 100%);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}

.content-section-subtitle {
  color: #374151;
  font-size: 1.25rem;
  font-weight: 500;
  margin: 0;
  line-height: 1.6;
  max-width: 600px;
  margin: 0 auto;
}

.content-filters {
  display: flex;
  gap: 0.75rem;
  position: relative;
  z-index: 2;
}

.filter-btn {
  display: flex;
  align-items: center;
  gap: 0.5rem;
  padding: 0.875rem 1.75rem;
  background: rgba(255, 255, 255, 0.9);
  border: 2px solid rgba(0, 0, 0, 0.1);
  border-radius: 30px;
  color: #374151;
  font-weight: 700;
  font-size: 0.95rem;
  transition: all 0.4s cubic-bezier(0.4, 0, 0.2, 1);
  cursor: pointer;
  position: relative;
  overflow: hidden;
  backdrop-filter: blur(10px);
  box-shadow: 0 2px 8px rgba(0, 0, 0, 0.1);
}

.filter-btn::before {
  content: "";
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  bottom: 0;
  background: rgba(59, 130, 246, 0.1);
  opacity: 0;
  transition: opacity 0.3s ease;
}

.filter-btn:hover {
  background: rgba(255, 255, 255, 1);
  border-color: rgba(59, 130, 246, 0.3);
  transform: translateY(-2px);
  box-shadow: 0 8px 25px rgba(0, 0, 0, 0.15);
}

.filter-btn.active {
  background: linear-gradient(135deg, #3b82f6 0%, #1d4ed8 100%);
  border-color: #3b82f6;
  color: white;
  box-shadow: 0 8px 25px rgba(59, 130, 246, 0.3);
  transform: translateY(-2px);
}

.filter-btn.active::before {
  opacity: 1;
}

.filter-btn i {
  font-size: 1rem;
  position: relative;
  z-index: 2;
}

.filter-btn span {
  position: relative;
  z-index: 2;
}

/* Animation Keyframes */
@keyframes fadeInUp {
  0% {
    opacity: 0;
    transform: translateY(30px);
  }
  100% {
    opacity: 1;
    transform: translateY(0);
  }
}

@keyframes fadeOut {
  0% {
    opacity: 1;
    transform: translateY(0);
  }
  100% {
    opacity: 0;
    transform: translateY(-30px);
  }
}

/* Library Navigation */
.library-nav {
  margin-bottom: 2.5rem;
}

.library-nav .nav-pills {
  background: #ffffff;
  border-radius: 16px;
  padding: 0.75rem;
  box-shadow: 0 8px 32px rgba(0, 0, 0, 0.08);
  border: 1px solid #f1f3f4;
  position: relative;
  overflow: hidden;
}

.library-nav .nav-pills::before {
  content: "";
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  bottom: 0;
  background: linear-gradient(
    135deg,
    rgba(102, 126, 234, 0.02) 0%,
    rgba(118, 75, 162, 0.02) 100%
  );
  pointer-events: none;
}

.library-nav .nav-link {
  border: none;
  background: transparent;
  color: #6c757d;
  font-weight: 700;
  padding: 1rem 2rem;
  border-radius: 12px;
  transition: all 0.4s cubic-bezier(0.4, 0, 0.2, 1);
  position: relative;
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 0.75rem;
  font-size: 0.95rem;
  letter-spacing: 0.025em;
  z-index: 2;
}

.library-nav .nav-link:hover {
  background: rgba(102, 126, 234, 0.08);
  color: #667eea;
  transform: translateY(-1px);
  box-shadow: 0 4px 12px rgba(102, 126, 234, 0.15);
}

.library-nav .nav-link.active {
  background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
  color: white;
  box-shadow: 0 8px 25px rgba(102, 126, 234, 0.4);
  transform: translateY(-2px);
}

.library-nav .nav-link.active::before {
  content: "";
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  bottom: 0;
  background: linear-gradient(
    135deg,
    rgba(255, 255, 255, 0.1) 0%,
    transparent 50%
  );
  border-radius: 12px;
  pointer-events: none;
}

.nav-badge {
  background: rgba(255, 255, 255, 0.25);
  color: white;
  font-size: 0.7rem;
  padding: 0.3rem 0.6rem;
  border-radius: 12px;
  font-weight: 700;
  margin-left: 0.5rem;
  text-shadow: 0 1px 2px rgba(0, 0, 0, 0.1);
  box-shadow: 0 2px 4px rgba(0, 0, 0, 0.1);
}

.library-nav .nav-link:not(.active) .nav-badge {
  background: #e9ecef;
  color: #6c757d;
  box-shadow: none;
  text-shadow: none;
}

/* Content Grid */
.content-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(320px, 1fr));
  gap: 2rem;
  margin-top: 1.5rem;
  padding: 0 0.5rem;
}

/* Content Cards */
.content-card {
  background: white;
  border-radius: 20px;
  padding: 2rem;
  box-shadow: 0 8px 32px rgba(0, 0, 0, 0.06);
  border: 1px solid #f1f3f4;
  transition: all 0.4s cubic-bezier(0.4, 0, 0.2, 1);
  cursor: pointer;
  position: relative;
  overflow: hidden;
  will-change: transform, box-shadow;
}

.content-card::before {
  content: "";
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  height: 5px;
  background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
  transform: scaleX(0);
  transition: transform 0.4s cubic-bezier(0.4, 0, 0.2, 1);
  border-radius: 20px 20px 0 0;
}

.content-card::after {
  content: "";
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  bottom: 0;
  background: linear-gradient(
    135deg,
    rgba(102, 126, 234, 0.02) 0%,
    rgba(118, 75, 162, 0.02) 100%
  );
  opacity: 0;
  transition: opacity 0.4s ease;
  pointer-events: none;
}

.content-card:hover {
  transform: translateY(-8px) scale(1.02);
  box-shadow: 0 20px 60px rgba(0, 0, 0, 0.12);
}

.content-card:hover::before {
  transform: scaleX(1);
}

.content-card:hover::after {
  opacity: 1;
}

.content-card:focus {
  outline: 2px solid #667eea;
  outline-offset: 2px;
}

.content-card:focus-visible {
  outline: 2px solid #667eea;
  outline-offset: 2px;
}

.content-card-header {
  display: flex;
  justify-content: space-between;
  align-items: flex-start;
  margin-bottom: 1.5rem;
  position: relative;
  z-index: 2;
}

.content-icon {
  width: 56px;
  height: 56px;
  background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
  border-radius: 16px;
  display: flex;
  align-items: center;
  justify-content: center;
  color: white;
  font-size: 1.5rem;
  box-shadow: 0 8px 20px rgba(102, 126, 234, 0.3);
  transition: all 0.3s ease;
}

.content-card:hover .content-icon {
  transform: scale(1.1) rotate(5deg);
  box-shadow: 0 12px 30px rgba(102, 126, 234, 0.4);
}

.content-badge .badge {
  font-size: 0.7rem;
  padding: 0.5rem 1rem;
  border-radius: 25px;
  font-weight: 700;
  letter-spacing: 0.025em;
  text-transform: uppercase;
  box-shadow: 0 2px 8px rgba(0, 0, 0, 0.1);
}

.content-card-body {
  margin-bottom: 2rem;
  position: relative;
  z-index: 2;
}

.content-title {
  font-size: 1.2rem;
  font-weight: 800;
  color: #2c3e50;
  margin-bottom: 1rem;
  line-height: 1.4;
  letter-spacing: -0.025em;
}

.content-excerpt {
  color: #6c757d;
  font-size: 0.95rem;
  line-height: 1.6;
  margin: 0;
  font-weight: 500;
}

.content-card-footer {
  border-top: 1px solid #f1f3f4;
  padding-top: 1.5rem;
  position: relative;
  z-index: 2;
}

.content-actions {
  display: flex;
  align-items: center;
  justify-content: space-between;
  color: #667eea;
  font-weight: 700;
  font-size: 0.95rem;
  letter-spacing: 0.025em;
}

.read-more {
  transition: all 0.3s ease;
  position: relative;
}

.read-more::after {
  content: "";
  position: absolute;
  bottom: -2px;
  left: 0;
  width: 0;
  height: 2px;
  background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
  transition: width 0.3s ease;
}

.content-card:hover .read-more {
  color: #764ba2;
}

.content-card:hover .read-more::after {
  width: 100%;
}

.content-card:hover .content-actions i {
  transform: translateX(6px) scale(1.1);
}

.content-actions i {
  transition: all 0.3s ease;
  font-size: 1.1rem;
}

/* Loading States */
.library-loading {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(320px, 1fr));
  gap: 2rem;
  margin-top: 1.5rem;
  padding: 0 0.5rem;
}

.skeleton-card {
  background: white;
  border-radius: 20px;
  padding: 2rem;
  box-shadow: 0 8px 32px rgba(0, 0, 0, 0.06);
  border: 1px solid #f1f3f4;
  animation: skeleton-loading 1.5s ease-in-out infinite;
}

.skeleton-header {
  display: flex;
  justify-content: space-between;
  align-items: flex-start;
  margin-bottom: 1.5rem;
}

.skeleton-icon {
  width: 56px;
  height: 56px;
  background: #e9ecef;
  border-radius: 16px;
  animation: skeleton-loading 1.5s ease-in-out infinite;
}

.skeleton-badge {
  width: 80px;
  height: 28px;
  background: #e9ecef;
  border-radius: 25px;
  animation: skeleton-loading 1.5s ease-in-out infinite;
}

.skeleton-title {
  width: 85%;
  height: 24px;
  background: #e9ecef;
  border-radius: 6px;
  margin-bottom: 1rem;
  animation: skeleton-loading 1.5s ease-in-out infinite;
}

.skeleton-excerpt {
  width: 100%;
  height: 18px;
  background: #e9ecef;
  border-radius: 4px;
  margin-bottom: 0.75rem;
  animation: skeleton-loading 1.5s ease-in-out infinite;
}

.skeleton-excerpt:last-child {
  width: 70%;
}

@keyframes skeleton-loading {
  0% {
    opacity: 1;
  }
  50% {
    opacity: 0.5;
  }
  100% {
    opacity: 1;
  }
}

/* Empty State */
.empty-state {
  text-align: center;
  padding: 4rem 2rem;
  color: #6c757d;
}

.empty-icon {
  width: 100px;
  height: 100px;
  background: linear-gradient(135deg, #f8f9fa 0%, #e9ecef 100%);
  border-radius: 50%;
  display: flex;
  align-items: center;
  justify-content: center;
  margin: 0 auto 2rem;
  font-size: 2.5rem;
  color: #adb5bd;
  box-shadow: 0 8px 32px rgba(0, 0, 0, 0.08);
  animation: float 3s ease-in-out infinite;
}

.empty-title {
  font-size: 1.5rem;
  font-weight: 700;
  color: #495057;
  margin-bottom: 1rem;
  letter-spacing: -0.025em;
}

.empty-description {
  color: #6c757d;
  margin: 0;
  font-size: 1rem;
  font-weight: 500;
  line-height: 1.6;
}

/* Document Detail Styles */
.document-detail-container {
  max-width: 100%;
  padding: 0;
  margin: 0;
}

.document-back {
  margin-bottom: 2rem;
}

.btn-back {
  display: inline-flex;
  align-items: center;
  gap: 0.5rem;
  background: #f8f9fa;
  border: 1px solid #e9ecef;
  color: #6c757d;
  padding: 0.75rem 1.5rem;
  border-radius: 12px;
  font-weight: 600;
  transition: all 0.3s ease;
  text-decoration: none;
}

.btn-back:hover {
  background: #e9ecef;
  color: #495057;
  transform: translateX(-2px);
}

.document-content-wrapper {
  background: white;
  border-radius: 0;
  padding: 1.5rem;
  margin: 0 0 2rem 0;
  box-shadow: none;
  border: none;
  max-width: none;
  width: 100%;
}

.document-content {
  line-height: 1.6;
  color: #2c3e50;
  font-size: 1rem;
  max-width: none;
  width: 100%;
}

.document-content h1,
.document-content h2,
.document-content h3,
.document-content h4,
.document-content h5,
.document-content h6 {
  color: #2c3e50;
  margin-top: 2rem;
  margin-bottom: 1rem;
  font-weight: 700;
}

.document-content p {
  margin-bottom: 1.2rem;
  text-align: justify;
  word-spacing: 0.1em;
}

.document-content ul,
.document-content ol {
  margin-bottom: 1.2rem;
  padding-left: 1.5rem;
}

.document-content li {
  margin-bottom: 0.5rem;
}

.document-content blockquote {
  border-left: 4px solid #667eea;
  padding-left: 1.5rem;
  margin: 2rem 0;
  font-style: italic;
  color: #6c757d;
  background: #f8f9fa;
  padding: 1.5rem;
  border-radius: 8px;
}

.document-content code {
  background: #f8f9fa;
  padding: 0.25rem 0.5rem;
  border-radius: 4px;
  font-family: "Monaco", "Menlo", "Ubuntu Mono", monospace;
  font-size: 0.9rem;
  color: #e83e8c;
}

.document-content pre {
  background: #f8f9fa;
  padding: 1.5rem;
  border-radius: 8px;
  overflow-x: auto;
  margin: 1.5rem 0;
}

.document-content pre code {
  background: none;
  padding: 0;
  color: #2c3e50;
}

/* Dark Mode Styles */
[data-bs-theme="dark"] .library-header {
  background: linear-gradient(135deg, #4a5568 0%, #2d3748 100%);
}

[data-bs-theme="dark"] .library-header::before,
[data-bs-theme="dark"] .library-header::after {
  background: radial-gradient(
    circle,
    rgba(255, 255, 255, 0.05) 0%,
    transparent 70%
  );
}

/* Unified Content Section Dark Mode */
[data-bs-theme="dark"] .content-header {
  background: linear-gradient(135deg, #1e293b 0%, #0f172a 100%);
  border-color: #334155;
}

[data-bs-theme="dark"] .content-header::before {
  background: linear-gradient(
    135deg,
    rgba(99, 102, 241, 0.15) 0%,
    rgba(139, 92, 246, 0.15) 100%
  );
}

[data-bs-theme="dark"] .content-header::after {
  background: linear-gradient(
    135deg,
    rgba(59, 130, 246, 0.12) 0%,
    rgba(16, 185, 129, 0.12) 100%
  );
}

[data-bs-theme="dark"] .content-section-title {
  color: #f1f5f9;
}

[data-bs-theme="dark"] .content-section-subtitle {
  color: #94a3b8;
}

[data-bs-theme="dark"] .filter-btn {
  background: rgba(255, 255, 255, 0.1);
  border-color: rgba(255, 255, 255, 0.2);
  color: white;
}

[data-bs-theme="dark"] .filter-btn:hover {
  background: rgba(255, 255, 255, 0.15);
  border-color: rgba(255, 255, 255, 0.3);
}

[data-bs-theme="dark"] .filter-btn.active {
  background: rgba(255, 255, 255, 0.2);
  border-color: rgba(255, 255, 255, 0.4);
  color: white;
}

[data-bs-theme="dark"] .library-nav .nav-pills {
  background: #2d3748;
  border-color: #4a5568;
}

[data-bs-theme="dark"] .library-nav .nav-pills::before {
  background: linear-gradient(
    135deg,
    rgba(102, 126, 234, 0.05) 0%,
    rgba(118, 75, 162, 0.05) 100%
  );
}

[data-bs-theme="dark"] .library-nav .nav-link {
  color: #a0aec0;
}

[data-bs-theme="dark"] .library-nav .nav-link:hover {
  background: rgba(102, 126, 234, 0.2);
  color: #667eea;
}

[data-bs-theme="dark"] .library-nav .nav-link:not(.active) .nav-badge {
  background: #4a5568;
  color: #a0aec0;
}

[data-bs-theme="dark"] .content-card {
  background: #2d3748;
  border-color: #4a5568;
}

[data-bs-theme="dark"] .content-card::after {
  background: linear-gradient(
    135deg,
    rgba(102, 126, 234, 0.05) 0%,
    rgba(118, 75, 162, 0.05) 100%
  );
}

/* Skeleton Loading Dark Mode */
[data-bs-theme="dark"] .skeleton-card {
  background: #2d3748;
  border-color: #4a5568;
}

[data-bs-theme="dark"] .skeleton-icon,
[data-bs-theme="dark"] .skeleton-badge,
[data-bs-theme="dark"] .skeleton-title,
[data-bs-theme="dark"] .skeleton-excerpt {
  background: #4a5568;
}

[data-bs-theme="dark"] .content-title {
  color: #e2e8f0;
}

[data-bs-theme="dark"] .content-excerpt {
  color: #a0aec0;
}

[data-bs-theme="dark"] .content-card-footer {
  border-color: #4a5568;
}

[data-bs-theme="dark"] .empty-state {
  color: #a0aec0;
}

[data-bs-theme="dark"] .empty-icon {
  background: linear-gradient(135deg, #4a5568 0%, #2d3748 100%);
  color: #718096;
}

[data-bs-theme="dark"] .empty-title {
  color: #e2e8f0;
}

[data-bs-theme="dark"] .btn-back {
  background: #4a5568;
  border-color: #718096;
  color: #a0aec0;
}

[data-bs-theme="dark"] .btn-back:hover {
  background: #718096;
  color: #e2e8f0;
}

[data-bs-theme="dark"] .document-content-wrapper {
  background: #2d3748;
  border-color: #4a5568;
}

[data-bs-theme="dark"] .document-content {
  color: #e2e8f0;
}

[data-bs-theme="dark"] .document-content h1,
[data-bs-theme="dark"] .document-content h2,
[data-bs-theme="dark"] .document-content h3,
[data-bs-theme="dark"] .document-content h4,
[data-bs-theme="dark"] .document-content h5,
[data-bs-theme="dark"] .document-content h6 {
  color: #e2e8f0;
}

[data-bs-theme="dark"] .document-content blockquote {
  background: #4a5568;
  color: #a0aec0;
}

[data-bs-theme="dark"] .document-content code {
  background: #4a5568;
  color: #f687b3;
}

[data-bs-theme="dark"] .document-content pre {
  background: #4a5568;
}

[data-bs-theme="dark"] .document-content pre code {
  color: #e2e8f0;
}

/* Mobile Responsive */
@media (max-width: 768px) {
  .unified-content-section {
    margin-top: 0.5rem;
  }

  .content-header {
    flex-direction: column;
    gap: 1.5rem;
    padding: 2rem 1.5rem;
  }

  .content-section-title {
    font-size: 2rem;
  }

  .content-section-subtitle {
    font-size: 1.1rem;
  }

  .content-search-filter-section {
    padding: 0.5rem 0.75rem;
    margin: 0.25rem 0;
    gap: 0.5rem;
  }

  .library-search-section {
    min-width: 120px;
  }

  .content-filters {
    gap: 0.25rem;
    flex-wrap: wrap;
    justify-content: center;
  }

  .filter-btn {
    padding: 0.75rem 1.5rem;
    font-size: 0.9rem;
  }

  .content-grid {
    grid-template-columns: 1fr;
    gap: 1.5rem;
  }

  .content-card {
    padding: 1.5rem;
  }

  .document-content-wrapper {
    padding: 1.25rem;
    margin: 0 0 1.5rem 0;
  }

  .library-nav .nav-link {
    padding: 0.8rem 1.5rem;
    font-size: 0.9rem;
  }

  .nav-badge {
    font-size: 0.65rem;
    padding: 0.25rem 0.5rem;
  }

  .skeleton-card {
    padding: 1.5rem;
  }
}

@media (max-width: 480px) {
  .unified-content-section {
    margin-top: 0;
  }

  .content-header {
    padding: 1.5rem 1.25rem;
  }

  .content-section-title {
    font-size: 1.75rem;
  }

  .content-section-subtitle {
    font-size: 1rem;
  }

  .content-search-filter-section {
    padding: 0.375rem 0.5rem;
    margin: 0.125rem 0;
    gap: 0.375rem;
    flex-direction: column;
    align-items: stretch;
  }

  .library-search-section {
    min-width: auto;
    width: 100%;
  }

  .content-filters {
    gap: 0.1875rem;
    justify-content: center;
  }

  .filter-btn {
    padding: 0.6rem 1.2rem;
    font-size: 0.85rem;
  }

  .content-card {
    padding: 1.25rem;
  }

  .content-card-header {
    margin-bottom: 1rem;
  }

  .content-icon {
    width: 48px;
    height: 48px;
    font-size: 1.25rem;
  }

  .document-content-wrapper {
    padding: 1rem;
    margin: 0 0 1rem 0;
  }

  .library-nav .nav-link {
    padding: 0.7rem 1.2rem;
    font-size: 0.85rem;
  }

  /* Mobile Vocabulary Styles */
  .vocab-header-content {
    flex-direction: column;
    gap: 1.5rem;
    text-align: center;
  }

  .vocab-main-title {
    font-size: 1.5rem;
  }

  .vocab-main-title i {
    font-size: 1.75rem;
  }

  .vocab-subtitle {
    font-size: 0.9rem;
  }

  .vocab-stats {
    justify-content: center;
  }

  .stat-item {
    min-width: 70px;
    padding: 0.75rem;
  }

  .stat-number {
    font-size: 2rem;
  }

  .stat-label {
    font-size: 0.75rem;
  }

  .tab-button {
    padding: 0.75rem 0.5rem;
    font-size: 0.85rem;
  }

  .tab-button span {
    display: none;
  }

  .tab-button i {
    font-size: 1.2rem;
  }

  .search-input {
    padding: 0.875rem 0.875rem 0.875rem 2.5rem;
    font-size: 0.9rem;
  }

  .search-icon {
    left: 0.875rem;
    font-size: 1rem;
  }

  .mode-toggle-btn {
    padding: 0.75rem 0.5rem;
    font-size: 0.85rem;
  }

  .mode-toggle-btn span {
    display: none;
  }

  .mode-toggle-btn i {
    font-size: 1.2rem;
  }

  .vocab-card-content {
    padding: 1.25rem;
  }

  .vocab-header {
    margin-bottom: 1.25rem;
  }

  .vocab-number {
    width: 28px;
    height: 28px;
    font-size: 0.8rem;
  }

  .action-btn {
    width: 36px;
    height: 36px;
    font-size: 1rem;
  }

  .japanese-text {
    font-size: 1.2rem;
  }

  .vietnamese-text {
    font-size: 1rem;
  }

  .divider i {
    font-size: 1rem;
    padding: 0.4rem;
  }

  .skeleton-card {
    padding: 1.25rem;
  }

  /* Mobile Vocabulary Compact Styles */
  .vocab-compact-header {
    padding: 0.75rem 1rem;
    border-radius: 0 0 16px 16px;
  }

  .header-top {
    flex-direction: column;
    gap: 1rem;
    align-items: stretch;
  }

  .title-section {
    justify-content: space-between;
    align-items: center;
  }

  .vocab-title {
    font-size: 1.2rem;
  }

  .vocab-title i {
    font-size: 1.4rem;
  }

  .vocab-count {
    font-size: 0.8rem;
    padding: 0.3rem 0.8rem;
    border-radius: 16px;
  }

  .tab-switcher {
    width: 100%;
    justify-content: center;
  }

  .tab-switch {
    flex: 1;
    padding: 0.6rem 0.75rem;
    font-size: 0.85rem;
    border-radius: 10px;
  }

  .tab-switch span {
    display: inline;
  }

  .tab-switch i {
    font-size: 1.1rem;
  }

  .search-wrapper input {
    padding: 0.6rem 0.75rem 0.6rem 2.25rem;
    font-size: 0.9rem;
    border-radius: 16px;
  }

  .search-wrapper i {
    left: 0.75rem;
    font-size: 0.9rem;
  }

  .desktop-table {
    margin: 0.75rem;
    border-radius: 16px;
  }

  .vocab-table th,
  .vocab-table td {
    padding: 0.75rem;
  }

  .mobile-cards {
    padding: 0.75rem;
  }

  .loading-state {
    padding: 1.5rem 0.75rem;
  }

  .loading-spinner {
    width: 28px;
    height: 28px;
  }

  .empty-state {
    padding: 2rem 0.75rem;
  }

  .empty-state i {
    font-size: 2rem;
  }

  .empty-state h3 {
    font-size: 1.1rem;
  }

  .vocab-content-compact {
    gap: 0.5rem;
  }

  .japanese-row,
  .vietnamese-row {
    gap: 0.5rem;
  }

  .flag-container {
    width: 28px;
    height: 28px;
  }

  .flag-emoji {
    font-size: 1rem;
  }

  .japanese-text {
    font-size: 1.1rem;
  }

  .vietnamese-text {
    font-size: 0.9rem;
  }

  /* Mobile Flashcard Styles - MOVED TO flashcard-style.css */
}

/* Practice Question Modal */
#practiceQuestionModal .modal-content {
  border-radius: 20px;
  border: none;
  box-shadow: 0 10px 40px rgba(0, 0, 0, 0.15);
  background: #ffffff;
}

#practiceQuestionModal .modal-header {
  background: linear-gradient(135deg, #f8f9fa 0%, #e9ecef 100%);
  color: #495057;
  border-radius: 20px 20px 0 0;
  border-bottom: 1px solid #dee2e6;
  padding: 1.5rem;
}

#practiceQuestionModal .modal-title {
  font-size: 1.3rem;
  font-weight: 600;
  margin: 0;
  color: #495057;
}

#practiceQuestionModal .btn-close {
  opacity: 0.6;
  color: #6c757d;
}

#practiceQuestionModal .btn-close:hover {
  opacity: 1;
  color: #495057;
}

#practiceQuestionModal .modal-body {
  padding: 2rem;
  background: #ffffff;
}

#practiceQuestionModal .question-image {
  max-width: 100%;
  height: auto;
  border-radius: 12px;
  box-shadow: 0 4px 15px rgba(0, 0, 0, 0.1);
}

#practiceQuestionModal .btn-outline-primary {
  border: 2px solid #6c757d;
  color: #495057;
  background: #f8f9fa;
  font-weight: 500;
  padding: 1rem 1.5rem;
  border-radius: 12px;
  transition: all 0.3s ease;
  text-align: left;
  white-space: normal;
  word-wrap: break-word;
}

#practiceQuestionModal .btn-outline-primary:hover {
  background-color: #e9ecef;
  border-color: #495057;
  color: #212529;
  transform: translateY(-2px);
  box-shadow: 0 4px 15px rgba(108, 117, 125, 0.2);
}

#practiceQuestionModal .btn-outline-primary:active {
  transform: translateY(0);
}

#practiceQuestionModal .modal-footer {
  background: #f8f9fa;
  border-radius: 0 0 20px 20px;
  border-top: 1px solid #dee2e6;
  padding: 1rem 2rem;
  color: #6c757d;
}

/* Dark Mode for Practice Question Modal */
[data-bs-theme="dark"] #practiceQuestionModal .modal-content {
  background-color: #2d2d2d;
  border-color: #495057;
}

[data-bs-theme="dark"] #practiceQuestionModal .modal-header {
  background: linear-gradient(135deg, #343a40 0%, #495057 100%);
  color: #e9ecef;
  border-color: #495057;
}

[data-bs-theme="dark"] #practiceQuestionModal .modal-title {
  color: #e9ecef;
}

[data-bs-theme="dark"] #practiceQuestionModal .btn-close {
  color: #adb5bd;
}

[data-bs-theme="dark"] #practiceQuestionModal .btn-close:hover {
  color: #e9ecef;
}

[data-bs-theme="dark"] #practiceQuestionModal .modal-body {
  background: #2d2d2d;
}

[data-bs-theme="dark"] #practiceQuestionModal .btn-outline-primary {
  border-color: #495057;
  color: #e9ecef;
  background: #343a40;
}

[data-bs-theme="dark"] #practiceQuestionModal .btn-outline-primary:hover {
  background-color: #495057;
  border-color: #6c757d;
  color: #f8f9fa;
  box-shadow: 0 4px 15px rgba(108, 117, 125, 0.3);
}

[data-bs-theme="dark"] #practiceQuestionModal .modal-footer {
  background: #343a40;
  border-color: #495057;
  color: #adb5bd;
}

/* Mobile Responsive */
@media (max-width: 768px) {
  .practice-container {
    padding: 0;
  }

  .mode-card {
    padding: 1rem;
    gap: 0.75rem;
  }

  .mode-icon {
    width: 50px;
    height: 50px;
    font-size: 1.3rem;
  }

  .mode-title {
    font-size: 1rem;
  }

  .mode-description {
    font-size: 0.85rem;
  }

  .setup-content {
    padding: 0;
  }

  .btn-start {
    width: 100%;
    padding: 1rem;
  }

  /* Mobile Modal Adjustments */
  #practiceQuestionModal .modal-dialog {
    margin: 0.5rem;
  }

  #practiceQuestionModal .modal-body {
    padding: 1.5rem;
  }

  #practiceQuestionModal .btn-outline-primary {
    padding: 0.75rem 1rem;
    font-size: 0.95rem;
  }
}

/* Dark Mode for Practice Interface */
[data-bs-theme="dark"] .mode-card {
  background: #2d2d2d;
  border-color: #495057;
  color: #e9ecef;
}

[data-bs-theme="dark"] .mode-card:hover {
  border-color: #60a5fa;
  box-shadow: 0 8px 25px rgba(96, 165, 250, 0.2);
}

[data-bs-theme="dark"] .mode-card.active {
  background: linear-gradient(135deg, #1a1a2e 0%, #16213e 100%);
  border-color: #60a5fa;
  box-shadow: 0 8px 25px rgba(96, 165, 250, 0.25);
}

[data-bs-theme="dark"] .mode-card.active::before {
  background: linear-gradient(90deg, #60a5fa, #8b5cf6);
}

[data-bs-theme="dark"] .mode-icon {
  background: #343a40;
  color: #adb5bd;
}

[data-bs-theme="dark"] .mode-card.active .mode-icon {
  background: linear-gradient(135deg, #60a5fa, #8b5cf6);
  color: #ffffff;
}

[data-bs-theme="dark"] .mode-title {
  color: #f8f9fa;
}

[data-bs-theme="dark"] .mode-description {
  color: #adb5bd;
}

[data-bs-theme="dark"] .setup-card {
  background: #2d2d2d;
  border-color: #495057;
}

[data-bs-theme="dark"] .setup-header {
  background: linear-gradient(135deg, #343a40 0%, #495057 100%);
  border-color: #495057;
}

[data-bs-theme="dark"] .setup-title {
  color: #e9ecef;
}

[data-bs-theme="dark"] .form-label {
  color: #e9ecef;
}

[data-bs-theme="dark"] .form-select {
  background-color: #343a40;
  border-color: #495057;
  color: #e9ecef;
}

[data-bs-theme="dark"] .form-select:focus {
  border-color: #60a5fa;
  box-shadow: 0 0 0 0.2rem rgba(96, 165, 250, 0.1);
}

[data-bs-theme="dark"] .select-icon {
  color: #adb5bd;
}

[data-bs-theme="dark"] .info-card {
  background: linear-gradient(135deg, #1a1a2e 0%, #16213e 100%);
  border-color: #495057;
}

[data-bs-theme="dark"] .info-content h5 {
  color: #60a5fa;
}

[data-bs-theme="dark"] .info-content p {
  color: #e9ecef;
}

[data-bs-theme="dark"] .btn-start {
  background: linear-gradient(135deg, #60a5fa 0%, #8b5cf6 100%);
  box-shadow: 0 4px 15px rgba(96, 165, 250, 0.3);
}

[data-bs-theme="dark"] .btn-start:hover {
  background: linear-gradient(135deg, #3b82f6 0%, #7c3aed 100%);
  box-shadow: 0 8px 25px rgba(96, 165, 250, 0.4);
}

/* == DDL-MOD: ÉP BUỘC NỘI DUNG TÀI LIỆU HIỂN THỊ TOÀN CHIỀU RỘNG == */
.main-content #content-display .card:not(.flashcard) {
  max-width: none !important;
  width: 100vw !important;
  margin: 0 !important;
  border-left: none !important;
  border-right: none !important;
  border-radius: 0 !important;
  box-shadow: none !important;
}
.main-content #content-display .card:not(.flashcard) .card-body {
  padding: 0.75rem 1rem !important;
  margin: 0 !important;
  width: 100% !important;
  max-width: 100% !important;
}

/* Reset tất cả containers để sử dụng toàn bộ chiều rộng */
.main-content .container,
.main-content .container-fluid,
.main-content .row,
.main-content .col,
.main-content [class*="col-"] {
  margin: 0 !important;
  padding-left: 0 !important;
  padding-right: 0 !important;
  width: 100vw !important;
  max-width: 100vw !important;
}

/* Đảm bảo document content wrapper sử dụng toàn bộ chiều rộng */
.main-content .document-content-wrapper {
  margin: 0 !important;
  padding: 0.75rem 1rem !important;
  width: 100vw !important;
  max-width: 100vw !important;
  border-radius: 0 !important;
  box-shadow: none !important;
}

/* Đảm bảo document content sử dụng toàn bộ chiều rộng */
.main-content .document-content {
  margin: 0 !important;
  padding: 0 !important;
  width: 100% !important;
  max-width: 100% !important;
}

/* ==================================================================== */
/* MODERN DASHBOARD STYLES - THIẾT KẾ MỚI HIỆN ĐẠI */
/* ==================================================================== */

.modern-dashboard {
  padding: 0;
  margin: 0;
  width: 100%;
  max-width: 100%;
}

/* Hero Welcome Section */
.hero-welcome {
  background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
  border-radius: 24px;
  padding: 2rem;
  margin-bottom: 2rem;
  position: relative;
  overflow: hidden;
  box-shadow: 0 20px 40px rgba(102, 126, 234, 0.3);
}

.hero-welcome::before {
  content: "";
  position: absolute;
  top: -50%;
  right: -20%;
  width: 200px;
  height: 200px;
  background: radial-gradient(
    circle,
    rgba(255, 255, 255, 0.1) 0%,
    transparent 70%
  );
  border-radius: 50%;
  animation: float 6s ease-in-out infinite;
}

.hero-welcome::after {
  content: "";
  position: absolute;
  bottom: -30%;
  left: -10%;
  width: 150px;
  height: 150px;
  background: radial-gradient(
    circle,
    rgba(255, 255, 255, 0.05) 0%,
    transparent 70%
  );
  border-radius: 50%;
  animation: float 8s ease-in-out infinite reverse;
}

.hero-content {
  display: flex;
  align-items: center;
  gap: 1.5rem;
  position: relative;
  z-index: 2;
}

.hero-avatar {
  position: relative;
  flex-shrink: 0;
}

.avatar-circle {
  width: 80px;
  height: 80px;
  background: rgba(255, 255, 255, 0.2);
  border-radius: 50%;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 2rem;
  font-weight: 700;
  color: white;
  backdrop-filter: blur(10px);
  border: 2px solid rgba(255, 255, 255, 0.3);
}

.avatar-status {
  position: absolute;
  bottom: 2px;
  right: 2px;
  width: 20px;
  height: 20px;
  background: #4ade80;
  border-radius: 50%;
  border: 3px solid white;
}

.hero-text {
  flex: 1;
}

.hero-title {
  font-size: 2rem;
  font-weight: 700;
  color: white;
  margin: 0 0 0.5rem 0;
  text-shadow: 0 2px 4px rgba(0, 0, 0, 0.2);
  letter-spacing: -0.025em;
}

.hero-subtitle {
  font-size: 1.1rem;
  color: rgba(255, 255, 255, 0.9);
  margin: 0;
  font-weight: 500;
  text-shadow: 0 1px 2px rgba(0, 0, 0, 0.1);
}

.hero-stats {
  display: flex;
  gap: 2rem;
  flex-shrink: 0;
}

.stat-item {
  text-align: center;
}

.stat-number {
  display: block;
  font-size: 2rem;
  font-weight: 700;
  color: white;
  text-shadow: 0 2px 4px rgba(0, 0, 0, 0.2);
}

.stat-label {
  display: block;
  font-size: 0.9rem;
  color: white !important;
  font-weight: 500;
  margin-top: 0.25rem;
}

/* Modern Course Section */
.modern-course-section {
  background: white;
  border-radius: 20px;
  padding: 1.5rem;
  margin-bottom: 2rem;
  box-shadow: 0 8px 32px rgba(0, 0, 0, 0.1);
  border: 1px solid rgba(0, 0, 0, 0.05);
}

.course-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  margin-bottom: 1.5rem;
}

.course-title {
  display: flex;
  align-items: center;
  gap: 1rem;
}

.course-icon {
  width: 48px;
  height: 48px;
  background: linear-gradient(135deg, #667eea, #764ba2);
  border-radius: 12px;
  display: flex;
  align-items: center;
  justify-content: center;
  color: white;
}

.course-icon svg {
  width: 24px;
  height: 24px;
}

.course-info h3 {
  font-size: 1.25rem;
  font-weight: 600;
  color: #1f2937;
  margin: 0 0 0.25rem 0;
}

.course-info p {
  font-size: 0.9rem;
  color: #6b7280;
  margin: 0;
}

.course-badge {
  width: 40px;
  height: 40px;
  background: linear-gradient(135deg, #667eea, #764ba2);
  border-radius: 50%;
  display: flex;
  align-items: center;
  justify-content: center;
  color: white;
  font-weight: 600;
  font-size: 0.9rem;
}

.course-selector {
  position: relative;
  margin-bottom: 1rem;
}

.modern-select {
  width: 100%;
  padding: 1rem 1.5rem;
  border: 2px solid #e5e7eb;
  border-radius: 12px;
  font-size: 1rem;
  font-weight: 500;
  color: #1f2937;
  background: white;
  appearance: none;
  transition: all 0.2s ease;
}

.modern-select:focus {
  outline: none;
  border-color: #667eea;
  box-shadow: 0 0 0 3px rgba(102, 126, 234, 0.1);
}

.select-arrow {
  position: absolute;
  right: 1rem;
  top: 50%;
  transform: translateY(-50%);
  pointer-events: none;
  color: #6b7280;
}

.select-arrow svg {
  width: 20px;
  height: 20px;
}

.current-course-display {
  display: flex;
  align-items: center;
  gap: 1rem;
  padding: 1rem;
  background: linear-gradient(
    135deg,
    rgba(102, 126, 234, 0.1),
    rgba(118, 75, 162, 0.1)
  );
  border-radius: 12px;
  border: 1px solid rgba(102, 126, 234, 0.2);
}

.current-course-icon {
  width: 40px;
  height: 40px;
  background: linear-gradient(135deg, #4ade80, #22c55e);
  border-radius: 10px;
  display: flex;
  align-items: center;
  justify-content: center;
  color: white;
}

.current-course-icon svg {
  width: 20px;
  height: 20px;
}

.current-course-text {
  flex: 1;
}

.current-label {
  display: block;
  font-size: 0.8rem;
  color: #6b7280;
  font-weight: 500;
  margin-bottom: 0.25rem;
}

.current-title {
  display: block;
  font-size: 1rem;
  font-weight: 600;
  color: #1f2937;
}

/* Section Headers */
.section-header {
  margin-bottom: 1.5rem;
}

.section-title {
  display: flex;
  align-items: center;
  gap: 1rem;
}

.title-icon {
  width: 48px;
  height: 48px;
  background: linear-gradient(135deg, #667eea, #764ba2);
  border-radius: 12px;
  display: flex;
  align-items: center;
  justify-content: center;
  color: white;
}

.title-icon svg {
  width: 24px;
  height: 24px;
}

.title-text h3 {
  font-size: 1.5rem;
  font-weight: 600;
  color: #1f2937;
  margin: 0 0 0.25rem 0;
}

.title-text p {
  font-size: 1rem;
  color: #6b7280;
  margin: 0;
}

/* Progress Overview */
.progress-overview {
  margin-bottom: 2rem;
}

.progress-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
  gap: 1.5rem;
}

.progress-card {
  background: white;
  border-radius: 16px;
  padding: 1.5rem;
  box-shadow: 0 4px 20px rgba(0, 0, 0, 0.08);
  border: 1px solid rgba(0, 0, 0, 0.05);
  transition: all 0.3s ease;
  display: flex;
  align-items: center;
  gap: 1rem;
}

.progress-card:hover {
  transform: translateY(-2px);
  box-shadow: 0 8px 30px rgba(0, 0, 0, 0.12);
}

.progress-icon {
  width: 56px;
  height: 56px;
  border-radius: 14px;
  display: flex;
  align-items: center;
  justify-content: center;
  flex-shrink: 0;
}

.vocab-progress .progress-icon {
  background: linear-gradient(135deg, #3b82f6, #1d4ed8);
  color: white;
}

.questions-progress .progress-icon {
  background: linear-gradient(135deg, #8b5cf6, #7c3aed);
  color: white;
}

.review-progress .progress-icon {
  background: linear-gradient(135deg, #f59e0b, #d97706);
  color: white;
}

.progress-icon svg {
  width: 28px;
  height: 28px;
}

.progress-content {
  flex: 1;
}

.progress-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  margin-bottom: 0.75rem;
}

.progress-label {
  font-size: 0.9rem;
  font-weight: 500;
  color: #6b7280;
}

.progress-value {
  font-size: 1.25rem;
  font-weight: 700;
  color: #1f2937;
}

.progress-bar {
  height: 8px;
  background: #f3f4f6;
  border-radius: 4px;
  overflow: hidden;
}

.progress-fill {
  height: 100%;
  background: linear-gradient(135deg, #667eea, #764ba2);
  border-radius: 4px;
  transition: width 0.8s ease;
}

/* Quick Actions */
.quick-actions {
  margin-bottom: 2rem;
}

.actions-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
  gap: 1.5rem;
}

.action-card {
  background: white;
  border-radius: 16px;
  padding: 1.5rem;
  box-shadow: 0 4px 20px rgba(0, 0, 0, 0.08);
  border: 1px solid rgba(0, 0, 0, 0.05);
  transition: all 0.3s ease;
  display: flex;
  align-items: center;
  gap: 1rem;
  text-decoration: none;
  color: inherit;
}

.action-card:hover {
  transform: translateY(-2px);
  box-shadow: 0 8px 30px rgba(0, 0, 0, 0.12);
  text-decoration: none;
  color: inherit;
}

.action-icon {
  width: 56px;
  height: 56px;
  border-radius: 14px;
  display: flex;
  align-items: center;
  justify-content: center;
  flex-shrink: 0;
}

.vocab-action .action-icon {
  background: linear-gradient(135deg, #3b82f6, #1d4ed8);
  color: white;
}

.practice-action .action-icon {
  background: linear-gradient(135deg, #8b5cf6, #7c3aed);
  color: white;
}

.test-action .action-icon {
  background: linear-gradient(135deg, #f59e0b, #d97706);
  color: white;
}

.action-icon svg {
  width: 28px;
  height: 28px;
}

.action-content {
  flex: 1;
}

.action-content h4 {
  font-size: 1.1rem;
  font-weight: 600;
  color: #1f2937;
  margin: 0 0 0.25rem 0;
}

.action-content p {
  font-size: 0.9rem;
  color: #6b7280;
  margin: 0;
}

.action-arrow {
  color: #9ca3af;
  transition: all 0.2s ease;
}

.action-card:hover .action-arrow {
  color: #667eea;
  transform: translateX(4px);
}

.action-arrow svg {
  width: 20px;
  height: 20px;
}

/* ==================================================================== */
/* UNIFIED DASHBOARD DESIGN - MODERN MOBILE-FIRST */
/* ==================================================================== */

.unified-dashboard {
  padding: 0;
  margin: 0;
  width: 100%;
  max-width: 100%;
  background: linear-gradient(135deg, #f8fafc 0%, #e2e8f0 100%);
  min-height: 100vh;
}

/* Modern Hero Section */
.unified-hero-section {
  background: linear-gradient(135deg, #667eea 0%, #764ba2 50%, #f093fb 100%);
  border-radius: 24px;
  padding: 2rem 1.5rem;
  margin: 1rem;
  position: relative;
  overflow: hidden;
  box-shadow: 0 20px 40px rgba(102, 126, 234, 0.3),
    0 0 0 1px rgba(255, 255, 255, 0.1), inset 0 1px 0 rgba(255, 255, 255, 0.2);
  animation: slideInUp 0.6s ease-out;
  backdrop-filter: blur(20px);
  border: 1px solid rgba(255, 255, 255, 0.15);
}

.unified-hero-section::before {
  content: "";
  position: absolute;
  top: -30%;
  right: -15%;
  width: 200px;
  height: 200px;
  background: radial-gradient(
    circle,
    rgba(255, 255, 255, 0.15) 0%,
    rgba(255, 255, 255, 0.05) 50%,
    transparent 70%
  );
  border-radius: 50%;
  animation: heroFloat 8s ease-in-out infinite;
}

.unified-hero-section::after {
  content: "";
  position: absolute;
  bottom: -25%;
  left: -10%;
  width: 150px;
  height: 150px;
  background: radial-gradient(
    circle,
    rgba(240, 147, 251, 0.2) 0%,
    rgba(240, 147, 251, 0.05) 50%,
    transparent 70%
  );
  border-radius: 50%;
  animation: heroFloat 10s ease-in-out infinite reverse;
}

@keyframes heroFloat {
  0%,
  100% {
    transform: translateY(0px) rotate(0deg) scale(1);
    opacity: 0.6;
  }
  50% {
    transform: translateY(-15px) rotate(180deg) scale(1.05);
    opacity: 1;
  }
}

.hero-content {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 1.5rem;
  position: relative;
  z-index: 2;
  text-align: center;
  padding: 0.5rem 0;
}

.hero-avatar-section {
  flex-shrink: 0;
}

.avatar-container {
  position: relative;
  width: 70px;
  height: 70px;
}

.avatar-circle {
  width: 100%;
  height: 100%;
  background: rgba(255, 255, 255, 0.2);
  border-radius: 50%;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 1.8rem;
  font-weight: 700;
  color: white;
  backdrop-filter: blur(10px);
  animation: avatarPulse 2s ease-in-out infinite;
}

.avatar-glow {
  position: absolute;
  top: -8px;
  left: -8px;
  right: -8px;
  bottom: -8px;
  background: radial-gradient(
    circle,
    rgba(255, 255, 255, 0.2) 0%,
    transparent 70%
  );
  border-radius: 50%;
  animation: glowPulse 3s ease-in-out infinite;
}

.avatar-status {
  position: absolute;
  bottom: 3px;
  right: 3px;
  width: 16px;
  height: 16px;
  background: #22c55e;
  border-radius: 50%;
  border: 2px solid white;
  animation: statusBlink 2s ease-in-out infinite;
}

@keyframes avatarPulse {
  0%,
  100% {
    transform: scale(1);
  }
  50% {
    transform: scale(1.05);
  }
}

@keyframes glowPulse {
  0%,
  100% {
    opacity: 0.2;
    transform: scale(1);
  }
  50% {
    opacity: 0.4;
    transform: scale(1.1);
  }
}

@keyframes statusBlink {
  0%,
  100% {
    opacity: 1;
  }
  50% {
    opacity: 0.7;
  }
}

.hero-text-section {
  flex: 1;
}

.hero-title {
  font-size: 1.8rem;
  font-weight: 700;
  color: white;
  margin: 0 0 0.5rem 0;
  text-shadow: 0 2px 8px rgba(0, 0, 0, 0.3);
  animation: fadeInLeft 0.8s ease-out 0.2s both;
  letter-spacing: -0.02em;
  line-height: 1.2;
}

.hero-subtitle {
  font-size: 1rem;
  color: rgba(255, 255, 255, 0.9);
  margin: 0;
  animation: fadeInLeft 0.8s ease-out 0.4s both;
  font-weight: 400;
  letter-spacing: 0.01em;
  line-height: 1.4;
  max-width: 280px;
}

.hero-stats-section {
  display: flex;
  gap: 0.75rem;
  flex-shrink: 0;
  justify-content: center;
  flex-wrap: wrap;
}

.stat-card {
  background: rgba(255, 255, 255, 0.15);
  border-radius: 16px;
  padding: 1rem;
  backdrop-filter: blur(15px);
  border: 1px solid rgba(255, 255, 255, 0.2);
  display: flex;
  align-items: center;
  gap: 0.75rem;
  min-width: 120px;
  animation: fadeInUp 0.8s ease-out 0.6s both;
  box-shadow: 0 4px 20px rgba(0, 0, 0, 0.1);
  transition: all 0.3s ease;
  position: relative;
  overflow: hidden;
}

.stat-card:hover {
  transform: translateY(-2px) scale(1.01);
  box-shadow: 0 8px 25px rgba(0, 0, 0, 0.15);
  border-color: rgba(255, 255, 255, 0.3);
  background: rgba(255, 255, 255, 0.2);
}

.stat-card::before {
  content: "";
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  bottom: 0;
  background: linear-gradient(
    135deg,
    rgba(255, 255, 255, 0.1) 0%,
    transparent 50%
  );
  opacity: 0;
  transition: opacity 0.3s ease;
}

.stat-card:hover::before {
  opacity: 1;
}

.stat-icon {
  width: 36px;
  height: 36px;
  background: rgba(255, 255, 255, 0.2);
  border-radius: 10px;
  display: flex;
  align-items: center;
  justify-content: center;
  color: white;
  box-shadow: 0 2px 8px rgba(0, 0, 0, 0.1);
  backdrop-filter: blur(8px);
  border: 1px solid rgba(255, 255, 255, 0.15);
  transition: all 0.3s ease;
}

.stat-icon:hover {
  background: rgba(255, 255, 255, 0.3);
  transform: scale(1.1);
  box-shadow: 0 4px 12px rgba(0, 0, 0, 0.15);
}

.stat-icon svg {
  width: 18px;
  height: 18px;
  filter: drop-shadow(0 1px 2px rgba(0, 0, 0, 0.2));
}

.stat-content {
  display: flex;
  flex-direction: column;
  gap: 0.25rem;
}

.stat-number {
  font-size: 1.8rem;
  font-weight: 700;
  color: white;
  line-height: 1.1;
  text-shadow: 0 2px 4px rgba(0, 0, 0, 0.3);
  letter-spacing: -0.02em;
}

.stat-label {
  font-size: 0.75rem;
  color: #1e293b !important;
  line-height: 1.2;
  font-weight: 500;
  text-shadow: none !important;
  letter-spacing: 0.01em;
}

/* Modern Progress Section */
.unified-progress-section {
  background: linear-gradient(135deg, #ffffff 0%, #f8fafc 100%);
  border-radius: 20px;
  padding: 1.5rem;
  margin: 1rem;
  box-shadow: 0 8px 32px rgba(0, 0, 0, 0.06);
  border: 1px solid rgba(255, 255, 255, 0.8);
  backdrop-filter: blur(20px);
  position: relative;
  overflow: hidden;
  animation: slideInUp 0.6s ease-out 0.2s both;
}

.unified-progress-section::before {
  content: "";
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  height: 3px;
  background: linear-gradient(90deg, #667eea 0%, #764ba2 50%, #f093fb 100%);
  border-radius: 20px 20px 0 0;
  animation: gradientShift 3s ease-in-out infinite;
}

@keyframes gradientShift {
  0%,
  100% {
    background-position: 0% 50%;
  }
  50% {
    background-position: 100% 50%;
  }
}

.progress-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
  gap: 1rem;
  margin-top: 1.5rem;
}

.unified-progress-card {
  background: white;
  border-radius: 16px;
  padding: 1.25rem;
  box-shadow: 0 4px 20px rgba(0, 0, 0, 0.06);
  border: 1px solid rgba(255, 255, 255, 0.8);
  transition: all 0.3s ease;
  position: relative;
  overflow: hidden;
  animation: fadeInUp 0.8s ease-out both;
}

.unified-progress-card:nth-child(1) {
  animation-delay: 0.4s;
}
.unified-progress-card:nth-child(2) {
  animation-delay: 0.6s;
}
.unified-progress-card:nth-child(3) {
  animation-delay: 0.8s;
}

.unified-progress-card:hover {
  transform: translateY(-4px);
  box-shadow: 0 16px 48px rgba(0, 0, 0, 0.12);
}

.unified-progress-card::before {
  content: "";
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  height: 3px;
  border-radius: 16px 16px 0 0;
}

.vocab-progress::before {
  background: linear-gradient(90deg, #667eea 0%, #764ba2 100%);
}

.questions-progress::before {
  background: linear-gradient(90deg, #f093fb 0%, #f5576c 100%);
}

.review-progress::before {
  background: linear-gradient(90deg, #4facfe 0%, #00f2fe 100%);
}

.progress-icon {
  width: 48px;
  height: 48px;
  border-radius: 12px;
  display: flex;
  align-items: center;
  justify-content: center;
  margin-bottom: 1rem;
}

.vocab-progress .progress-icon {
  background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
  color: white;
}

.questions-progress .progress-icon {
  background: linear-gradient(135deg, #f093fb 0%, #f5576c 100%);
  color: white;
}

.review-progress .progress-icon {
  background: linear-gradient(135deg, #4facfe 0%, #00f2fe 100%);
  color: white;
}

.progress-icon svg {
  width: 24px;
  height: 24px;
}

.progress-content {
  flex: 1;
}

.progress-header {
  display: flex;
  justify-content: space-between;
  align-items: center;
  margin-bottom: 1rem;
}

.progress-label {
  font-size: 0.9rem;
  font-weight: 600;
  color: #64748b;
}

.progress-value {
  font-size: 1.5rem;
  font-weight: 700;
  color: #1e293b;
}

.progress-bar {
  height: 8px;
  background: #e2e8f0;
  border-radius: 4px;
  overflow: hidden;
}

.progress-fill {
  height: 100%;
  border-radius: 4px;
  transition: width 1s ease-out;
}

.vocab-progress .progress-fill {
  background: linear-gradient(90deg, #667eea 0%, #764ba2 100%);
}

.questions-progress .progress-fill {
  background: linear-gradient(90deg, #f093fb 0%, #f5576c 100%);
}

.review-progress .progress-fill {
  background: linear-gradient(90deg, #4facfe 0%, #00f2fe 100%);
}

/* Modern Actions Section */
.unified-actions-section {
  background: linear-gradient(135deg, #ffffff 0%, #f8fafc 100%);
  border-radius: 20px;
  padding: 1.5rem;
  margin: 1rem;
  box-shadow: 0 8px 32px rgba(0, 0, 0, 0.06);
  border: 1px solid rgba(255, 255, 255, 0.8);
  backdrop-filter: blur(20px);
  position: relative;
  overflow: hidden;
  animation: slideInUp 0.6s ease-out 0.4s both;
}

.unified-actions-section::before {
  content: "";
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  height: 3px;
  background: linear-gradient(90deg, #667eea 0%, #764ba2 50%, #f093fb 100%);
  border-radius: 20px 20px 0 0;
  animation: gradientShift 3s ease-in-out infinite;
}

.actions-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
  gap: 1rem;
  margin-top: 1.5rem;
}

.unified-action-card {
  background: white;
  border-radius: 16px;
  padding: 1.25rem;
  box-shadow: 0 4px 20px rgba(0, 0, 0, 0.06);
  border: 1px solid rgba(255, 255, 255, 0.8);
  transition: all 0.3s ease;
  position: relative;
  overflow: hidden;
  cursor: pointer;
  animation: fadeInUp 0.8s ease-out both;
}

.unified-action-card:nth-child(1) {
  animation-delay: 0.6s;
}
.unified-action-card:nth-child(2) {
  animation-delay: 0.8s;
}
.unified-action-card:nth-child(3) {
  animation-delay: 1s;
}
.unified-action-card:nth-child(4) {
  animation-delay: 1.2s;
}

.unified-action-card:hover {
  transform: translateY(-4px);
  box-shadow: 0 16px 48px rgba(0, 0, 0, 0.12);
}

.action-background {
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  bottom: 0;
  background: linear-gradient(
    135deg,
    rgba(102, 126, 234, 0.05) 0%,
    rgba(118, 75, 162, 0.05) 100%
  );
  opacity: 0;
  transition: opacity 0.3s ease;
}

.unified-action-card:hover .action-background {
  opacity: 1;
}

.action-content {
  display: flex;
  align-items: center;
  gap: 1rem;
  position: relative;
  z-index: 2;
}

.action-icon {
  width: 48px;
  height: 48px;
  background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
  border-radius: 12px;
  display: flex;
  align-items: center;
  justify-content: center;
  color: white;
  flex-shrink: 0;
  transition: all 0.3s ease;
}

.unified-action-card:hover .action-icon {
  transform: scale(1.1);
}

.action-icon svg {
  width: 24px;
  height: 24px;
}

.action-text {
  flex: 1;
}

.action-text h4 {
  font-size: 1.1rem;
  font-weight: 600;
  color: #1e293b;
  margin: 0 0 0.25rem 0;
}

.action-text p {
  font-size: 0.9rem;
  color: #64748b;
  margin: 0;
}

.action-arrow {
  width: 32px;
  height: 32px;
  background: rgba(102, 126, 234, 0.1);
  border-radius: 8px;
  display: flex;
  align-items: center;
  justify-content: center;
  color: #667eea;
  transition: all 0.3s ease;
  flex-shrink: 0;
}

.unified-action-card:hover .action-arrow {
  background: #667eea;
  color: white;
  transform: translateX(4px);
}

.action-arrow svg {
  width: 16px;
  height: 16px;
}

@keyframes slideInUp {
  from {
    opacity: 0;
    transform: translateY(30px);
  }
  to {
    opacity: 1;
    transform: translateY(0);
  }
}

@keyframes fadeInUp {
  from {
    opacity: 0;
    transform: translateY(20px);
  }
  to {
    opacity: 1;
    transform: translateY(0);
  }
}

@keyframes fadeInLeft {
  from {
    opacity: 0;
    transform: translateX(-30px);
  }
  to {
    opacity: 1;
    transform: translateX(0);
  }
}

/* ==================================================================== */
/* ENHANCED COURSE SECTION WITH ANIMATIONS */
/* ==================================================================== */

.enhanced-course-section {
  background: linear-gradient(135deg, #ffffff 0%, #f8f9fa 100%);
  border-radius: 24px;
  padding: 2rem;
  margin-bottom: 2rem;
  box-shadow: 0 20px 40px rgba(0, 0, 0, 0.08);
  border: 1px solid rgba(255, 255, 255, 0.2);
  backdrop-filter: blur(20px);
  position: relative;
  overflow: hidden;
  animation: slideInUp 0.6s ease-out;
}

.enhanced-course-section::before {
  content: "";
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  height: 4px;
  background: linear-gradient(90deg, #667eea 0%, #764ba2 50%, #f093fb 100%);
  border-radius: 24px 24px 0 0;
  animation: gradientShift 3s ease-in-out infinite;
}

.enhanced-course-section::after {
  content: "";
  position: absolute;
  top: -50%;
  right: -20%;
  width: 200px;
  height: 200px;
  background: radial-gradient(
    circle,
    rgba(102, 126, 234, 0.1) 0%,
    transparent 70%
  );
  border-radius: 50%;
  animation: float 6s ease-in-out infinite;
}

@keyframes slideInUp {
  from {
    opacity: 0;
    transform: translateY(30px);
  }
  to {
    opacity: 1;
    transform: translateY(0);
  }
}

@keyframes gradientShift {
  0%,
  100% {
    background-position: 0% 50%;
  }
  50% {
    background-position: 100% 50%;
  }
}

@keyframes float {
  0%,
  100% {
    transform: translateY(0px) rotate(0deg);
  }
  50% {
    transform: translateY(-20px) rotate(180deg);
  }
}

/* Course Header Enhanced */
.course-header-enhanced {
  display: flex;
  align-items: center;
  justify-content: space-between;
  margin-bottom: 2rem;
  animation: fadeInLeft 0.8s ease-out 0.2s both;
}

.course-title-enhanced {
  display: flex;
  align-items: center;
  gap: 1.5rem;
}

.course-icon-enhanced {
  position: relative;
  width: 60px;
  height: 60px;
}

.icon-background {
  width: 100%;
  height: 100%;
  background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
  border-radius: 16px;
  display: flex;
  align-items: center;
  justify-content: center;
  color: white;
  box-shadow: 0 8px 32px rgba(102, 126, 234, 0.3);
  transition: all 0.3s ease;
  animation: pulse 2s ease-in-out infinite;
}

.icon-background:hover {
  transform: scale(1.05);
  box-shadow: 0 12px 40px rgba(102, 126, 234, 0.4);
}

.icon-glow {
  position: absolute;
  top: -10px;
  left: -10px;
  right: -10px;
  bottom: -10px;
  background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
  border-radius: 20px;
  opacity: 0.3;
  filter: blur(20px);
  animation: glow 2s ease-in-out infinite alternate;
}

@keyframes pulse {
  0%,
  100% {
    transform: scale(1);
  }
  50% {
    transform: scale(1.05);
  }
}

@keyframes glow {
  0% {
    opacity: 0.3;
    transform: scale(1);
  }
  100% {
    opacity: 0.6;
    transform: scale(1.1);
  }
}

.course-icon-enhanced svg {
  width: 28px;
  height: 28px;
  animation: iconFloat 3s ease-in-out infinite;
}

@keyframes iconFloat {
  0%,
  100% {
    transform: translateY(0px);
  }
  50% {
    transform: translateY(-3px);
  }
}

.course-info-enhanced {
  flex: 1;
}

.course-title-text {
  font-size: 1.5rem;
  font-weight: 700;
  color: #2d3748;
  margin: 0 0 0.5rem 0;
  background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
  animation: textGlow 2s ease-in-out infinite alternate;
}

@keyframes textGlow {
  0% {
    filter: brightness(1);
  }
  100% {
    filter: brightness(1.2);
  }
}

.course-subtitle-text {
  font-size: 1rem;
  color: #718096;
  margin: 0;
  animation: fadeIn 1s ease-out 0.4s both;
}

@keyframes fadeIn {
  from {
    opacity: 0;
  }
  to {
    opacity: 1;
  }
}

.course-status-enhanced {
  display: flex;
  align-items: center;
  gap: 1rem;
}

.status-indicator {
  display: flex;
  align-items: center;
  gap: 0.5rem;
  background: rgba(34, 197, 94, 0.1);
  padding: 0.75rem 1.25rem;
  border-radius: 25px;
  border: 1px solid rgba(34, 197, 94, 0.2);
  animation: statusPulse 2s ease-in-out infinite;
}

@keyframes statusPulse {
  0%,
  100% {
    box-shadow: 0 0 0 0 rgba(34, 197, 94, 0.4);
  }
  50% {
    box-shadow: 0 0 0 10px rgba(34, 197, 94, 0);
  }
}

.status-dot {
  width: 10px;
  height: 10px;
  background: #22c55e;
  border-radius: 50%;
  animation: dotPulse 1.5s ease-in-out infinite;
}

@keyframes dotPulse {
  0%,
  100% {
    opacity: 1;
    transform: scale(1);
  }
  50% {
    opacity: 0.7;
    transform: scale(1.2);
  }
}

.status-text {
  font-size: 0.9rem;
  font-weight: 600;
  color: #16a34a;
}

.course-count-badge {
  width: 50px;
  height: 50px;
  background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
  border-radius: 50%;
  display: flex;
  align-items: center;
  justify-content: center;
  color: white;
  font-weight: 700;
  font-size: 1.2rem;
  box-shadow: 0 8px 32px rgba(102, 126, 234, 0.3);
  animation: badgeFloat 3s ease-in-out infinite;
}

@keyframes badgeFloat {
  0%,
  100% {
    transform: translateY(0px) rotate(0deg);
  }
  50% {
    transform: translateY(-5px) rotate(180deg);
  }
}

.count-number {
  animation: numberCount 0.8s ease-out;
}

@keyframes numberCount {
  from {
    transform: scale(0);
  }
  to {
    transform: scale(1);
  }
}

/* Course Selector Enhanced */
.course-selector-enhanced {
  margin-bottom: 1.5rem;
  animation: fadeInUp 0.8s ease-out 0.4s both;
}

@keyframes fadeInUp {
  from {
    opacity: 0;
    transform: translateY(20px);
  }
  to {
    opacity: 1;
    transform: translateY(0);
  }
}

.selector-container {
  position: relative;
  background: white;
  border-radius: 20px;
  border: 2px solid #e2e8f0;
  transition: all 0.3s ease;
  overflow: hidden;
  box-shadow: 0 4px 20px rgba(0, 0, 0, 0.05);
}

.selector-container:hover {
  border-color: #667eea;
  box-shadow: 0 8px 32px rgba(102, 126, 234, 0.15);
  transform: translateY(-2px);
}

.selector-background {
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  bottom: 0;
  background: linear-gradient(
    135deg,
    rgba(102, 126, 234, 0.05) 0%,
    rgba(118, 75, 162, 0.05) 100%
  );
  opacity: 0;
  transition: opacity 0.3s ease;
}

.selector-container:hover .selector-background {
  opacity: 1;
}

.enhanced-select {
  width: 100%;
  padding: 1.25rem 3.5rem 1.25rem 1.5rem;
  border: none;
  background: transparent;
  font-size: 1.1rem;
  font-weight: 500;
  color: #2d3748;
  cursor: pointer;
  appearance: none;
  outline: none;
  position: relative;
  z-index: 2;
}

.enhanced-select:focus {
  outline: none;
}

.select-icon-enhanced {
  position: absolute;
  right: 1.5rem;
  top: 50%;
  transform: translateY(-50%);
  color: #667eea;
  pointer-events: none;
  z-index: 3;
  transition: all 0.3s ease;
}

.selector-container:hover .select-icon-enhanced {
  transform: translateY(-50%) rotate(180deg);
}

.select-icon-enhanced svg {
  width: 24px;
  height: 24px;
}

/* Current Course Enhanced */
.current-course-enhanced {
  position: relative;
  background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
  border-radius: 20px;
  padding: 1.5rem;
  color: white;
  overflow: hidden;
  animation: slideInRight 0.8s ease-out 0.6s both;
}

@keyframes slideInRight {
  from {
    opacity: 0;
    transform: translateX(30px);
  }
  to {
    opacity: 1;
    transform: translateX(0);
  }
}

.current-course-background {
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  bottom: 0;
  background: url('data:image/svg+xml,<svg xmlns="http://www.w3.org/2000/svg" viewBox="0 0 100 100"><defs><pattern id="grain" width="100" height="100" patternUnits="userSpaceOnUse"><circle cx="50" cy="50" r="1" fill="rgba(255,255,255,0.1)"/></pattern></defs><rect width="100" height="100" fill="url(%23grain)"/></svg>');
  opacity: 0.3;
  animation: backgroundMove 20s linear infinite;
}

@keyframes backgroundMove {
  0% {
    transform: translateX(0) translateY(0);
  }
  100% {
    transform: translateX(-100px) translateY(-100px);
  }
}

.current-course-content {
  display: flex;
  align-items: center;
  gap: 1.5rem;
  position: relative;
  z-index: 2;
}

.current-course-icon {
  flex-shrink: 0;
}

.checkmark-circle {
  width: 50px;
  height: 50px;
  background: rgba(255, 255, 255, 0.2);
  border-radius: 50%;
  display: flex;
  align-items: center;
  justify-content: center;
  backdrop-filter: blur(10px);
  animation: checkmarkPulse 2s ease-in-out infinite;
}

@keyframes checkmarkPulse {
  0%,
  100% {
    transform: scale(1);
  }
  50% {
    transform: scale(1.1);
  }
}

.checkmark-circle svg {
  width: 24px;
  height: 24px;
  color: white;
  animation: checkmarkDraw 1s ease-out;
}

@keyframes checkmarkDraw {
  0% {
    stroke-dashoffset: 100;
  }
  100% {
    stroke-dashoffset: 0;
  }
}

.current-course-text {
  flex: 1;
}

.current-label {
  display: block;
  font-size: 0.9rem;
  color: rgba(255, 255, 255, 0.9);
  margin-bottom: 0.25rem;
  animation: fadeInLeft 0.8s ease-out 0.8s both;
  text-shadow: 0 1px 2px rgba(0, 0, 0, 0.3);
}

@keyframes fadeInLeft {
  from {
    opacity: 0;
    transform: translateX(-20px);
  }
  to {
    opacity: 1;
    transform: translateX(0);
  }
}

.current-title {
  display: block;
  font-size: 1.2rem;
  font-weight: 600;
  color: white;
  animation: fadeInLeft 0.8s ease-out 1s both;
  text-shadow: 0 2px 4px rgba(0, 0, 0, 0.4);
}

.progress-indicator {
  flex-shrink: 0;
}

.progress-ring {
  position: relative;
  width: 60px;
  height: 60px;
}

.circular-chart {
  width: 100%;
  height: 100%;
  transform: rotate(-90deg);
}

.circle-bg {
  fill: none;
  stroke: rgba(255, 255, 255, 0.2);
  stroke-width: 3;
}

.circle {
  fill: none;
  stroke: white;
  stroke-width: 3;
  stroke-linecap: round;
  stroke-dasharray: 0, 100;
  animation: progressFill 2s ease-out 1.2s both;
}

@keyframes progressFill {
  to {
    stroke-dasharray: 75, 100;
  }
}

.progress-text {
  position: absolute;
  top: 50%;
  left: 50%;
  transform: translate(-50%, -50%);
  font-size: 0.8rem;
  font-weight: 600;
  color: white;
  animation: fadeIn 1s ease-out 1.4s both;
}

/* Mobile responsive - Đảm bảo hoạt động tốt trên mobile */
@media (max-width: 768px) {
  .main-content {
    padding: 0.5rem !important;
    margin: 0 !important;
    width: 100vw !important;
    max-width: 100vw !important;
  }

  #content-display {
    margin: 0 !important;
    padding: 0 !important;
    width: 100vw !important;
    max-width: 100vw !important;
  }

  .unified-dashboard {
    padding: 0.5rem !important;
  }

  .unified-hero-section {
    padding: 1rem !important;
    margin-bottom: 1rem !important;
    border-radius: 16px !important;
  }

  .hero-content {
    flex-direction: column !important;
    text-align: center !important;
    gap: 1rem !important;
  }

  .avatar-container {
    width: 60px !important;
    height: 60px !important;
  }

  .avatar-circle {
    font-size: 1.5rem !important;
  }

  .hero-title {
    font-size: 1.5rem !important;
  }

  .hero-subtitle {
    font-size: 1rem !important;
  }

  .hero-stats-section {
    gap: 0.75rem !important;
    justify-content: center !important;
  }

  .stat-card {
    min-width: 100px !important;
    padding: 0.75rem !important;
  }

  .stat-icon {
    width: 28px !important;
    height: 28px !important;
  }

  .stat-icon svg {
    width: 16px !important;
    height: 16px !important;
  }

  .stat-number {
    font-size: 2rem !important;
  }

  .stat-label {
    font-size: 0.75rem !important;
    color: white !important;
  }

  .unified-progress-section {
    padding: 1rem !important;
    margin-bottom: 1rem !important;
    border-radius: 16px !important;
  }

  .progress-grid {
    grid-template-columns: 1fr !important;
    gap: 1rem !important;
  }

  .unified-progress-card {
    padding: 1rem !important;
    border-radius: 16px !important;
  }

  .progress-icon {
    width: 40px !important;
    height: 40px !important;
    margin-bottom: 0.75rem !important;
  }

  .progress-icon svg {
    width: 20px !important;
    height: 20px !important;
  }

  .progress-value {
    font-size: 1.25rem !important;
  }

  .unified-actions-section {
    padding: 1rem !important;
    margin-bottom: 1rem !important;
    border-radius: 16px !important;
  }

  .actions-grid {
    grid-template-columns: repeat(2, 1fr) !important;
    gap: 1rem !important;
  }

  .unified-action-card {
    padding: 1rem !important;
    border-radius: 16px !important;
  }

  .action-icon {
    width: 40px !important;
    height: 40px !important;
  }

  .action-icon svg {
    width: 20px !important;
    height: 20px !important;
  }

  .action-text h4 {
    font-size: 1rem !important;
  }

  .action-text p {
    font-size: 0.8rem !important;
  }

  .action-arrow {
    width: 28px !important;
    height: 28px !important;
  }

  .action-arrow svg {
    width: 14px !important;
    height: 14px !important;
  }

  .hero-welcome {
    padding: 1rem !important;
    margin-bottom: 1rem !important;
    border-radius: 12px !important;
  }

  .hero-content {
    flex-direction: column !important;
    text-align: center !important;
    gap: 0.5rem !important;
  }

  .hero-avatar {
    margin-bottom: 0.5rem !important;
  }

  .avatar-circle {
    width: 50px !important;
    height: 50px !important;
    font-size: 1.25rem !important;
  }

  .hero-title {
    font-size: 1.25rem !important;
    margin-bottom: 0.25rem !important;
  }

  .hero-subtitle {
    font-size: 0.8rem !important;
    margin-bottom: 0.75rem !important;
  }

  .hero-stats {
    gap: 0.75rem !important;
    justify-content: center !important;
  }

  .stat-item {
    padding: 0.5rem 0.75rem !important;
    border-radius: 8px !important;
  }

  .stat-number {
    font-size: 2rem !important;
  }

  .stat-label {
    font-size: 0.7rem !important;
    color: white !important;
  }

  .modern-course-section {
    padding: 0.75rem !important;
    margin-bottom: 1rem !important;
    border-radius: 12px !important;
  }

  .course-header {
    flex-direction: column !important;
    align-items: flex-start !important;
    gap: 0.5rem !important;
  }

  .course-title {
    flex-direction: row !important;
    align-items: center !important;
    gap: 0.5rem !important;
  }

  .course-icon {
    width: 24px !important;
    height: 24px !important;
  }

  .course-info h3 {
    font-size: 1rem !important;
    margin-bottom: 0.25rem !important;
  }

  .course-info p {
    font-size: 0.75rem !important;
  }

  .course-badge {
    width: 28px !important;
    height: 28px !important;
    font-size: 0.8rem !important;
  }

  .modern-select {
    font-size: 0.85rem !important;
    padding: 0.5rem 0.75rem !important;
  }

  .progress-overview {
    padding: 0.75rem !important;
    margin-bottom: 1rem !important;
    border-radius: 12px !important;
  }

  .section-title {
    flex-direction: row !important;
    align-items: center !important;
    gap: 0.5rem !important;
  }

  .title-icon {
    width: 24px !important;
    height: 24px !important;
  }

  .title-text h3 {
    font-size: 1rem !important;
    margin-bottom: 0.25rem !important;
  }

  .title-text p {
    font-size: 0.75rem !important;
  }

  .progress-grid {
    grid-template-columns: 1fr !important;
    gap: 0.5rem !important;
  }

  .progress-card {
    padding: 0.75rem !important;
    border-radius: 8px !important;
  }

  .progress-icon {
    width: 24px !important;
    height: 24px !important;
  }

  .progress-header {
    margin-bottom: 0.5rem !important;
  }

  .progress-label {
    font-size: 0.8rem !important;
  }

  .progress-value {
    font-size: 1rem !important;
  }

  .progress-bar {
    height: 4px !important;
  }

  .quick-actions {
    padding: 0.75rem !important;
    margin-bottom: 1rem !important;
    border-radius: 12px !important;
  }

  .actions-grid {
    grid-template-columns: repeat(2, 1fr) !important;
    gap: 0.5rem !important;
  }

  .action-card {
    padding: 0.75rem !important;
    border-radius: 8px !important;
  }

  .action-icon {
    width: 24px !important;
    height: 24px !important;
    margin-bottom: 0.5rem !important;
  }

  .action-content h4 {
    font-size: 0.8rem !important;
    margin-bottom: 0.25rem !important;
  }

  .action-content p {
    font-size: 0.7rem !important;
  }

  /* Enhanced Course Section Mobile */
  .enhanced-course-section {
    padding: 1rem !important;
    margin-bottom: 1rem !important;
    border-radius: 16px !important;
  }

  .course-header-enhanced {
    flex-direction: column !important;
    align-items: flex-start !important;
    gap: 1rem !important;
    margin-bottom: 1rem !important;
  }

  .course-title-enhanced {
    gap: 1rem !important;
  }

  .course-icon-enhanced {
    width: 50px !important;
    height: 50px !important;
  }

  .icon-background {
    border-radius: 12px !important;
  }

  .course-icon-enhanced svg {
    width: 24px !important;
    height: 24px !important;
  }

  .course-title-text {
    font-size: 1.25rem !important;
  }

  .course-subtitle-text {
    font-size: 0.9rem !important;
  }

  .course-status-enhanced {
    gap: 0.75rem !important;
  }

  .status-indicator {
    padding: 0.5rem 1rem !important;
    border-radius: 20px !important;
  }

  .status-text {
    font-size: 0.8rem !important;
  }

  .course-count-badge {
    width: 40px !important;
    height: 40px !important;
    font-size: 1rem !important;
  }

  .enhanced-select {
    padding: 1rem 3rem 1rem 1rem !important;
    font-size: 1rem !important;
  }

  .select-icon-enhanced {
    right: 1rem !important;
  }

  .select-icon-enhanced svg {
    width: 20px !important;
    height: 20px !important;
  }

  .current-course-enhanced {
    padding: 1rem !important;
    border-radius: 16px !important;
  }

  .current-course-content {
    gap: 1rem !important;
  }

  .checkmark-circle {
    width: 40px !important;
    height: 40px !important;
  }

  .checkmark-circle svg {
    width: 20px !important;
    height: 20px !important;
  }

  .current-label {
    font-size: 0.8rem !important;
    color: rgba(255, 255, 255, 0.9) !important;
    text-shadow: 0 1px 2px rgba(0, 0, 0, 0.3) !important;
  }

  .current-title {
    font-size: 1rem !important;
    color: white !important;
    text-shadow: 0 2px 4px rgba(0, 0, 0, 0.4) !important;
  }

  .progress-ring {
    width: 50px !important;
    height: 50px !important;
  }

  .progress-text {
    font-size: 0.7rem !important;
  }
}

/* Extra small mobile devices (480px and below) */
@media (max-width: 480px) {
  .main-content {
    padding: 0.25rem !important;
  }

  .unified-dashboard {
    padding: 0.25rem !important;
  }

  .unified-hero-section {
    padding: 0.75rem !important;
    margin-bottom: 0.75rem !important;
    border-radius: 12px !important;
  }

  .hero-content {
    gap: 0.75rem !important;
  }

  .avatar-container {
    width: 50px !important;
    height: 50px !important;
  }

  .avatar-circle {
    font-size: 1.25rem !important;
  }

  .hero-title {
    font-size: 1.25rem !important;
  }

  .hero-subtitle {
    font-size: 0.9rem !important;
  }

  .hero-stats-section {
    gap: 0.5rem !important;
  }

  .stat-card {
    min-width: 80px !important;
    padding: 0.5rem !important;
    border-radius: 12px !important;
  }

  .stat-icon {
    width: 24px !important;
    height: 24px !important;
  }

  .stat-icon svg {
    width: 14px !important;
    height: 14px !important;
  }

  .stat-number {
    font-size: 2rem !important;
    color: white !important;
  }

  .stat-label {
    font-size: 0.7rem !important;
    color: white !important;
  }

  .unified-progress-section {
    padding: 0.75rem !important;
    margin-bottom: 0.75rem !important;
    border-radius: 12px !important;
  }

  .progress-grid {
    gap: 0.75rem !important;
  }

  .unified-progress-card {
    padding: 0.75rem !important;
    border-radius: 12px !important;
  }

  .progress-icon {
    width: 36px !important;
    height: 36px !important;
    margin-bottom: 0.5rem !important;
  }

  .progress-icon svg {
    width: 18px !important;
    height: 18px !important;
  }

  .progress-value {
    font-size: 1.1rem !important;
  }

  .unified-actions-section {
    padding: 0.75rem !important;
    margin-bottom: 0.75rem !important;
    border-radius: 12px !important;
  }

  .actions-grid {
    gap: 0.75rem !important;
  }

  .unified-action-card {
    padding: 0.75rem !important;
    border-radius: 12px !important;
  }

  .action-icon {
    width: 36px !important;
    height: 36px !important;
  }

  .action-icon svg {
    width: 18px !important;
    height: 18px !important;
  }

  .action-text h4 {
    font-size: 0.9rem !important;
  }

  .action-text p {
    font-size: 0.75rem !important;
  }

  .action-arrow {
    width: 24px !important;
    height: 24px !important;
  }

  .action-arrow svg {
    width: 12px !important;
    height: 12px !important;
  }

  .modern-dashboard {
    padding: 0.25rem !important;
  }

  .hero-welcome {
    padding: 0.75rem !important;
    margin-bottom: 0.75rem !important;
    border-radius: 8px !important;
  }

  .hero-content {
    gap: 0.25rem !important;
  }

  .avatar-circle {
    width: 40px !important;
    height: 40px !important;
    font-size: 1rem !important;
  }

  .hero-title {
    font-size: 1.1rem !important;
  }

  .hero-subtitle {
    font-size: 0.75rem !important;
    margin-bottom: 0.5rem !important;
  }

  .hero-stats {
    gap: 0.5rem !important;
  }

  .stat-item {
    padding: 0.4rem 0.6rem !important;
    border-radius: 6px !important;
  }

  .stat-number {
    font-size: 2rem !important;
  }

  .stat-label {
    font-size: 0.65rem !important;
    color: white !important;
  }

  .modern-course-section {
    padding: 0.5rem !important;
    margin-bottom: 0.75rem !important;
    border-radius: 8px !important;
  }

  .course-header {
    gap: 0.25rem !important;
  }

  .course-title {
    gap: 0.25rem !important;
  }

  .course-icon {
    width: 20px !important;
    height: 20px !important;
  }

  .course-info h3 {
    font-size: 0.9rem !important;
  }

  .course-info p {
    font-size: 0.7rem !important;
  }

  .course-badge {
    width: 24px !important;
    height: 24px !important;
    font-size: 0.7rem !important;
  }

  .modern-select {
    font-size: 0.8rem !important;
    padding: 0.4rem 0.6rem !important;
  }

  .progress-overview {
    padding: 0.5rem !important;
    margin-bottom: 0.75rem !important;
    border-radius: 8px !important;
  }

  .section-title {
    gap: 0.25rem !important;
  }

  .title-icon {
    width: 20px !important;
    height: 20px !important;
  }

  .title-text h3 {
    font-size: 0.9rem !important;
  }

  .title-text p {
    font-size: 0.7rem !important;
  }

  .progress-grid {
    gap: 0.25rem !important;
  }

  .progress-card {
    padding: 0.5rem !important;
    border-radius: 6px !important;
  }

  .progress-icon {
    width: 20px !important;
    height: 20px !important;
  }

  .progress-header {
    margin-bottom: 0.25rem !important;
  }

  .progress-label {
    font-size: 0.75rem !important;
  }

  .progress-value {
    font-size: 0.9rem !important;
  }

  .progress-bar {
    height: 3px !important;
  }

  .quick-actions {
    padding: 0.5rem !important;
    margin-bottom: 0.75rem !important;
    border-radius: 8px !important;
  }

  .actions-grid {
    gap: 0.25rem !important;
  }

  .action-card {
    padding: 0.5rem !important;
    border-radius: 6px !important;
  }

  .action-icon {
    width: 20px !important;
    height: 20px !important;
    margin-bottom: 0.25rem !important;
  }

  .action-content h4 {
    font-size: 0.75rem !important;
  }

  .action-content p {
    font-size: 0.65rem !important;
  }

  /* Enhanced Course Section Extra Small Mobile */
  .enhanced-course-section {
    padding: 0.75rem !important;
    margin-bottom: 0.75rem !important;
    border-radius: 12px !important;
  }

  .course-header-enhanced {
    gap: 0.75rem !important;
    margin-bottom: 0.75rem !important;
  }

  .course-title-enhanced {
    gap: 0.75rem !important;
  }

  .course-icon-enhanced {
    width: 40px !important;
    height: 40px !important;
  }

  .icon-background {
    border-radius: 10px !important;
  }

  .course-icon-enhanced svg {
    width: 20px !important;
    height: 20px !important;
  }

  .course-title-text {
    font-size: 1.1rem !important;
  }

  .course-subtitle-text {
    font-size: 0.8rem !important;
  }

  .course-status-enhanced {
    gap: 0.5rem !important;
  }

  .status-indicator {
    padding: 0.4rem 0.8rem !important;
    border-radius: 16px !important;
  }

  .status-text {
    font-size: 0.75rem !important;
  }

  .course-count-badge {
    width: 36px !important;
    height: 36px !important;
    font-size: 0.9rem !important;
  }

  .enhanced-select {
    padding: 0.75rem 2.5rem 0.75rem 0.75rem !important;
    font-size: 0.9rem !important;
  }

  .select-icon-enhanced {
    right: 0.75rem !important;
  }

  .select-icon-enhanced svg {
    width: 18px !important;
    height: 18px !important;
  }

  .current-course-enhanced {
    padding: 0.75rem !important;
    border-radius: 12px !important;
  }

  .current-course-content {
    gap: 0.75rem !important;
  }

  .checkmark-circle {
    width: 36px !important;
    height: 36px !important;
  }

  .checkmark-circle svg {
    width: 18px !important;
    height: 18px !important;
  }

  .current-label {
    font-size: 0.75rem !important;
    color: rgba(255, 255, 255, 0.9) !important;
    text-shadow: 0 1px 2px rgba(0, 0, 0, 0.3) !important;
  }

  .current-title {
    font-size: 0.9rem !important;
    color: white !important;
    text-shadow: 0 2px 4px rgba(0, 0, 0, 0.4) !important;
  }

  .progress-ring {
    width: 45px !important;
    height: 45px !important;
  }

  .progress-text {
    font-size: 0.65rem !important;
  }

  .main-content #content-display .card:not(.flashcard) {
    width: 100vw !important;
    max-width: 100vw !important;
    margin: 0 !important;
    border-radius: 0 !important;
    border-left: none !important;
    border-right: none !important;
    box-shadow: none !important;
  }

  .main-content #content-display .card:not(.flashcard) .card-body {
    padding: 0.75rem 1rem !important;
    margin: 0 !important;
    width: 100% !important;
    max-width: 100% !important;
  }

  /* Reset tất cả Bootstrap containers trên mobile */
  .main-content .container,
  .main-content .container-fluid,
  .main-content .row,
  .main-content .col,
  .main-content [class*="col-"] {
    margin: 0 !important;
    padding-left: 0 !important;
    padding-right: 0 !important;
    width: 100vw !important;
    max-width: 100vw !important;
  }

  /* Đảm bảo document content wrapper trên mobile */
  .main-content .document-content-wrapper {
    margin: 0 !important;
    padding: 0.75rem 1rem !important;
    width: 100vw !important;
    max-width: 100vw !important;
    border-radius: 0 !important;
    box-shadow: none !important;
  }

  /* Đảm bảo document content trên mobile */
  .main-content .document-content {
    margin: 0 !important;
    padding: 0 !important;
    width: 100% !important;
    max-width: 100% !important;
  }

  /* Modern Dashboard Mobile */
  .modern-dashboard {
    padding: 1rem;
  }

  .hero-welcome {
    padding: 1.5rem;
    margin-bottom: 1.5rem;
  }

  .hero-content {
    flex-direction: column;
    text-align: center;
    gap: 1rem;
  }

  .hero-stats {
    gap: 1.5rem;
  }

  .modern-course-section {
    padding: 1.25rem;
    margin-bottom: 1.5rem;
  }

  .course-header {
    flex-direction: column;
    align-items: flex-start;
    gap: 1rem;
  }

  .progress-grid {
    grid-template-columns: 1fr;
    gap: 1rem;
  }

  .actions-grid {
    grid-template-columns: 1fr;
    gap: 1rem;
  }

  .section-title {
    flex-direction: column;
    align-items: flex-start;
    gap: 0.75rem;
  }
}

/* MỚI: CSS cho Audio Player */
#audio-list-container .list-group-item .play-indicator {
  display: none;
  font-size: 1.2rem;
  color: var(--primary-color);
}

#audio-list-container .list-group-item.playing {
  background-color: var(--bs-primary-bg-subtle);
  color: var(--bs-primary-text-emphasis);
  font-weight: 600;
}

#audio-list-container .list-group-item.playing .play-indicator {
  display: inline-block;
}

[data-bs-theme="dark"] #audio-list-container .list-group-item.playing {
  background-color: rgba(var(--bs-primary-rgb), 0.2) !important;
}

/* ==================================================================== */
/* MOCK TEST TAB - MODERN & SCIENTIFIC DESIGN */
/* ==================================================================== */

.mock-test-container {
  padding: 0;
  max-width: 1200px;
  margin: 0 auto;
  background: transparent;
  min-height: auto;
}

.mock-test-header {
  text-align: center;
  margin-bottom: 2.5rem;
  position: relative;
}

.mock-test-title {
  font-size: 2.5rem;
  font-weight: 800;
  background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
  margin-bottom: 0.5rem;
  letter-spacing: -0.025em;
}

.mock-test-subtitle {
  font-size: 1.1rem;
  color: #64748b;
  font-weight: 500;
  margin-bottom: 1rem;
}

.mock-test-stats {
  display: flex;
  justify-content: center;
  gap: 2rem;
  margin-top: 1.5rem;
}

.stat-item {
  text-align: center;
  padding: 1rem 1.5rem;
  background: rgba(255, 255, 255, 0.7);
  border-radius: 16px;
  backdrop-filter: blur(10px);
  border: 1px solid rgba(255, 255, 255, 0.3);
  box-shadow: 0 4px 15px rgba(0, 0, 0, 0.05);
}

.stat-number {
  font-size: 2rem;
  font-weight: 700;
  color: #3730a3;
  display: block;
}

.stat-label {
  font-size: 0.9rem;
  color: #64748b;
  font-weight: 500;
  margin-top: 0.25rem;
}

.mock-test-card {
  background: linear-gradient(135deg, #ffffff 0%, #f8fafc 100%);
  border-radius: 24px;
  padding: 2.5rem;
  box-shadow: 0 20px 60px rgba(0, 0, 0, 0.1);
  border: 1px solid rgba(255, 255, 255, 0.8);
  position: relative;
  overflow: hidden;
  margin-bottom: 2rem;
}

.mock-test-card::before {
  content: "";
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  height: 4px;
  background: linear-gradient(90deg, #667eea 0%, #764ba2 100%);
}

.mock-test-card-header {
  display: flex;
  align-items: center;
  gap: 1rem;
  margin-bottom: 2rem;
}

.mock-test-icon {
  width: 60px;
  height: 60px;
  background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
  border-radius: 16px;
  display: flex;
  align-items: center;
  justify-content: center;
  color: white;
  font-size: 1.8rem;
  box-shadow: 0 8px 25px rgba(102, 126, 234, 0.3);
}

.mock-test-card-title {
  font-size: 1.8rem;
  font-weight: 700;
  color: #1e293b;
  margin: 0;
  letter-spacing: -0.025em;
}

.mock-test-info {
  display: flex;
  align-items: center;
  gap: 0.75rem;
  background: rgba(102, 126, 234, 0.1);
  padding: 1rem 1.25rem;
  border-radius: 12px;
  margin-bottom: 2rem;
  border-left: 4px solid #667eea;
}

.mock-test-info-icon {
  color: #667eea;
  font-size: 1.2rem;
}

.mock-test-info-text {
  color: #475569;
  font-size: 1rem;
  font-weight: 500;
  line-height: 1.5;
}

.mock-test-form {
  margin-bottom: 2rem;
}

.form-group {
  margin-bottom: 1.5rem;
}

.form-label {
  display: block;
  font-size: 1.1rem;
  font-weight: 600;
  color: #374151;
  margin-bottom: 0.75rem;
}

.select-wrapper {
  position: relative;
  display: inline-block;
  width: 100%;
  max-width: 300px;
}

.select-wrapper::after {
  content: "";
  position: absolute;
  right: 1rem;
  top: 50%;
  transform: translateY(-50%);
  width: 0;
  height: 0;
  border-left: 6px solid transparent;
  border-right: 6px solid transparent;
  border-top: 8px solid #64748b;
  pointer-events: none;
}

.mock-test-select {
  width: 100%;
  padding: 1rem 1.25rem;
  padding-right: 3rem;
  border: 2px solid #e2e8f0;
  border-radius: 12px;
  background: #ffffff;
  font-size: 1rem;
  font-weight: 500;
  color: #374151;
  cursor: pointer;
  transition: all 0.3s ease;
  appearance: none;
  -webkit-appearance: none;
  -moz-appearance: none;
}

.mock-test-select:focus {
  outline: none;
  border-color: #667eea;
  box-shadow: 0 0 0 3px rgba(102, 126, 234, 0.1);
}

.mock-test-select:hover {
  border-color: #c7d2fe;
}

.mock-test-options {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(120px, 1fr));
  gap: 1rem;
  margin-top: 1rem;
}

.option-card {
  padding: 1rem;
  border: 2px solid #e2e8f0;
  border-radius: 12px;
  background: #ffffff;
  cursor: pointer;
  transition: all 0.3s ease;
  text-align: center;
  position: relative;
}

.option-card:hover {
  border-color: #c7d2fe;
  transform: translateY(-2px);
  box-shadow: 0 8px 25px rgba(102, 126, 234, 0.15);
}

.option-card.selected {
  border-color: #667eea;
  background: linear-gradient(135deg, #f0f4ff 0%, #e0e7ff 100%);
  box-shadow: 0 8px 25px rgba(102, 126, 234, 0.2);
}

.option-card.selected::before {
  content: "✓";
  position: absolute;
  top: 0.5rem;
  right: 0.5rem;
  width: 20px;
  height: 20px;
  background: #667eea;
  color: white;
  border-radius: 50%;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 0.8rem;
  font-weight: 700;
}

.option-number {
  font-size: 1.2rem;
  font-weight: 700;
  color: #3730a3;
  margin-bottom: 0.25rem;
}

.option-label {
  font-size: 0.9rem;
  color: #64748b;
  font-weight: 500;
}

.mock-test-start-btn {
  width: 100%;
  padding: 1.25rem 2rem;
  background: linear-gradient(135deg, #ef4444 0%, #dc2626 100%);
  border: none;
  border-radius: 16px;
  color: white;
  font-size: 1.1rem;
  font-weight: 700;
  cursor: pointer;
  transition: all 0.3s ease;
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 0.75rem;
  box-shadow: 0 8px 25px rgba(239, 68, 68, 0.3);
  position: relative;
  overflow: hidden;
}

.mock-test-start-btn::before {
  content: "";
  position: absolute;
  top: 0;
  left: -100%;
  width: 100%;
  height: 100%;
  background: linear-gradient(
    90deg,
    transparent,
    rgba(255, 255, 255, 0.2),
    transparent
  );
  transition: left 0.5s ease;
}

.mock-test-start-btn:hover::before {
  left: 100%;
}

.mock-test-start-btn:hover {
  transform: translateY(-2px);
  box-shadow: 0 12px 35px rgba(239, 68, 68, 0.4);
}

.mock-test-start-btn:active {
  transform: translateY(0);
}

.mock-test-start-icon {
  font-size: 1.3rem;
}

.mock-test-features {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
  gap: 1.5rem;
  margin-top: 2rem;
}

.feature-card {
  background: rgba(255, 255, 255, 0.8);
  border-radius: 16px;
  padding: 1.5rem;
  border: 1px solid rgba(255, 255, 255, 0.5);
  backdrop-filter: blur(10px);
  transition: all 0.3s ease;
}

.feature-card:hover {
  transform: translateY(-4px);
  box-shadow: 0 12px 30px rgba(0, 0, 0, 0.1);
}

.feature-icon {
  width: 50px;
  height: 50px;
  background: linear-gradient(135deg, #10b981 0%, #059669 100%);
  border-radius: 12px;
  display: flex;
  align-items: center;
  justify-content: center;
  color: white;
  font-size: 1.3rem;
  margin-bottom: 1rem;
}

.feature-title {
  font-size: 1.1rem;
  font-weight: 600;
  color: #1e293b;
  margin-bottom: 0.5rem;
}

.feature-description {
  color: #64748b;
  font-size: 0.95rem;
  line-height: 1.5;
}

/* Dark Mode for Mock Test */
[data-bs-theme="dark"] .mock-test-container {
  background: linear-gradient(135deg, #1e293b 0%, #0f172a 100%);
}

[data-bs-theme="dark"] .mock-test-title {
  background: linear-gradient(135deg, #a5b4fc 0%, #c4b5fd 100%);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}

[data-bs-theme="dark"] .mock-test-subtitle {
  color: #94a3b8;
}

[data-bs-theme="dark"] .stat-item {
  background: rgba(30, 41, 59, 0.7);
  border-color: rgba(71, 85, 105, 0.3);
}

[data-bs-theme="dark"] .stat-number {
  color: #a5b4fc;
}

[data-bs-theme="dark"] .stat-label {
  color: #94a3b8;
}

[data-bs-theme="dark"] .mock-test-card {
  background: linear-gradient(135deg, #1e293b 0%, #334155 100%);
  border-color: rgba(71, 85, 105, 0.5);
}

[data-bs-theme="dark"] .mock-test-card-title {
  color: #f1f5f9;
}

[data-bs-theme="dark"] .mock-test-info {
  background: rgba(165, 180, 252, 0.1);
  border-left-color: #a5b4fc;
}

[data-bs-theme="dark"] .mock-test-info-icon {
  color: #a5b4fc;
}

[data-bs-theme="dark"] .mock-test-info-text {
  color: #cbd5e0;
}

[data-bs-theme="dark"] .form-label {
  color: #e2e8f0;
}

[data-bs-theme="dark"] .mock-test-select {
  background: #334155;
  border-color: #475569;
  color: #f1f5f9;
}

[data-bs-theme="dark"] .mock-test-select:focus {
  border-color: #a5b4fc;
  box-shadow: 0 0 0 3px rgba(165, 180, 252, 0.1);
}

[data-bs-theme="dark"] .option-card {
  background: #334155;
  border-color: #475569;
}

[data-bs-theme="dark"] .option-card:hover {
  border-color: #a5b4fc;
}

[data-bs-theme="dark"] .option-card.selected {
  background: linear-gradient(135deg, #1e1b4b 0%, #312e81 100%);
  border-color: #a5b4fc;
}

[data-bs-theme="dark"] .option-number {
  color: #a5b4fc;
}

[data-bs-theme="dark"] .option-label {
  color: #94a3b8;
}

[data-bs-theme="dark"] .feature-card {
  background: rgba(30, 41, 59, 0.8);
  border-color: rgba(71, 85, 105, 0.5);
}

[data-bs-theme="dark"] .feature-title {
  color: #f1f5f9;
}

[data-bs-theme="dark"] .feature-description {
  color: #94a3b8;
}

/* Mobile Responsive */
@media (max-width: 768px) {
  .mock-test-container {
    padding: 0;
  }

  .mock-test-title {
    font-size: 2rem;
  }

  .mock-test-stats {
    flex-direction: column;
    gap: 1rem;
  }

  .mock-test-card {
    padding: 1.5rem;
    border-radius: 20px;
  }

  .mock-test-card-header {
    flex-direction: column;
    text-align: center;
    gap: 0.75rem;
  }

  .mock-test-icon {
    width: 50px;
    height: 50px;
    font-size: 1.5rem;
  }

  .mock-test-card-title {
    font-size: 1.5rem;
  }

  .mock-test-options {
    grid-template-columns: repeat(2, 1fr);
  }

  .mock-test-features {
    grid-template-columns: 1fr;
  }

  .mock-test-start-btn {
    padding: 1rem 1.5rem;
    font-size: 1rem;
  }
}

/* Practice Topic Select Styles */
.practice-topic-select {
  display: flex;
  justify-content: center;
  align-items: center;
  margin: 0 auto;
}

#practice-topic-select {
  text-align: center;
  margin: 0 auto;
}

.select-wrapper {
  display: flex;
  justify-content: center;
  align-items: center;
}

.form-group {
  display: flex;
  flex-direction: column;
  align-items: center;
  text-align: center;
}

.form-group .form-label {
  text-align: center;
  margin-bottom: 0.5rem;
}

/* Force override for stat labels */
.stat-label {
  color: #1e293b !important;
  text-shadow: none !important;
}

/* ==================================================================== */
/* GAMIFICATION STATS MODAL */
/* ==================================================================== */

#gamification-stats-modal .modal-dialog {
  max-width: 95%;
  margin: 0.5rem auto;
}

#gamification-stats-modal .modal-content {
  border-radius: 16px;
  border: none;
  box-shadow: 0 8px 25px rgba(0, 0, 0, 0.15);
  overflow: hidden;
}

#gamification-stats-modal .modal-header {
  border-bottom: 1px solid #f0f0f0;
  padding: 1rem;
  background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
  color: white;
}

#gamification-stats-modal .modal-header .modal-title {
  font-size: 1.1rem;
  font-weight: 600;
  margin: 0;
}

#gamification-stats-modal .modal-header .btn-close {
  filter: invert(1);
  opacity: 0.8;
}

#gamification-stats-modal .modal-body {
  padding: 1rem;
  background: #fafafa;
}

#gamification-stats-modal .modal-footer {
  border-top: 1px solid #f0f0f0;
  padding: 0.75rem 1rem;
  background: white;
}

/* Stats Container - Mobile First */
.stats-container {
  display: flex;
  flex-direction: column;
  gap: 0.75rem;
}

.stat-row {
  display: flex;
  gap: 0.75rem;
}

.stat-item {
  flex: 1;
  display: flex;
  align-items: center;
  background: white;
  border-radius: 12px;
  padding: 0.75rem;
  box-shadow: 0 2px 8px rgba(0, 0, 0, 0.06);
  border: 1px solid #f0f0f0;
  transition: all 0.2s ease;
}

.stat-item:hover {
  transform: translateY(-1px);
  box-shadow: 0 4px 12px rgba(0, 0, 0, 0.1);
}

.stat-item .stat-icon {
  font-size: 1.5rem;
  margin-right: 0.75rem;
  flex-shrink: 0;
}

.stat-content {
  flex: 1;
  min-width: 0;
}

.stat-value {
  font-size: 1.25rem;
  font-weight: 700;
  color: #2c3e50;
  line-height: 1.2;
  margin-bottom: 0.125rem;
}

.stat-label {
  font-size: 0.7rem;
  color: #7f8c8d;
  line-height: 1.2;
  font-weight: 500;
}

/* Progress Bar */
#gamification-stats-modal .progress {
  height: 6px;
  border-radius: 3px;
  background: #e9ecef;
  margin: 0.75rem 0 0.5rem;
}

#gamification-stats-modal .progress-bar {
  background: linear-gradient(90deg, #667eea 0%, #764ba2 100%);
  border-radius: 3px;
}

#gamification-stats-modal small {
  font-size: 0.65rem;
  color: #6c757d;
  display: block;
  text-align: center;
}

/* Mobile-Only Gamification Modal */
#gamification-stats-modal .modal-dialog {
  max-width: 500px;
  margin: 1.75rem auto;
}

#gamification-stats-modal .modal-header {
  padding: 1.25rem;
}

#gamification-stats-modal .modal-body {
  padding: 1.25rem;
}

#gamification-stats-modal .modal-footer {
  padding: 1rem 1.25rem;
}

.stats-container {
  gap: 1rem;
}

.stat-row {
  gap: 1rem;
}

.stat-item {
  padding: 1rem;
}

.stat-item .stat-icon {
  font-size: 1.75rem;
  margin-right: 1rem;
}

.stat-value {
  font-size: 1.5rem;
}

.stat-label {
  font-size: 0.8rem;
}

#gamification-stats-modal .progress {
  height: 8px;
  margin: 1rem 0 0.75rem;
}

#gamification-stats-modal small {
  font-size: 0.75rem;
}