:root {
  --font-sans: system-ui, -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, Oxygen, Ubuntu, Cantarell, 'Open Sans', 'Helvetica Neue', sans-serif;
  --primary: #4f46e5;
  --primary-hover: #4338ca;
  --primary-light: #e0e7ff;
  --secondary: #ec4899;
  --accent-purple: #8b5cf6;
  --bg-primary: #ffffff;
  --bg-secondary: #f8fafc;
  --bg-tertiary: #f1f5f9;
  --card-bg: #ffffff;
  --card-border: #e2e8f0;
  --text-primary: #0f172a;
  --text-secondary: #475569;
  --text-muted: #64748b;
  --border-color: #e2e8f0;
  --header-bg: rgba(255, 255, 255, 0.85);
  --shadow-sm: 0 1px 2px 0 rgba(0, 0, 0, 0.05);
  --shadow-md: 0 4px 6px -1px rgba(0, 0, 0, 0.07), 0 2px 4px -2px rgba(0, 0, 0, 0.05);
  --shadow-lg: 0 10px 15px -3px rgba(0, 0, 0, 0.08), 0 4px 6px -4px rgba(0, 0, 0, 0.04);
  --shadow-xl: 0 20px 25px -5px rgba(0, 0, 0, 0.1), 0 8px 10px -6px rgba(0, 0, 0, 0.04);
  --radius-sm: 8px;
  --radius-md: 12px;
  --radius-lg: 18px;
  --radius-full: 9999px;
  --gradient-brand: linear-gradient(135deg, #6366f1 0%, #8b5cf6 50%, #ec4899 100%);
  --gradient-glow: linear-gradient(135deg, rgba(99, 102, 241, 0.15), rgba(236, 72, 153, 0.15));
}

[data-theme="dark"] {
  --bg-primary: #09090b;
  --bg-secondary: #121216;
  --bg-tertiary: #18181b;
  --card-bg: #141418;
  --card-border: #27272a;
  --text-primary: #f8fafc;
  --text-secondary: #cbd5e1;
  --text-muted: #94a3b8;
  --border-color: #27272a;
  --header-bg: rgba(9, 9, 11, 0.85);
  --shadow-sm: 0 1px 2px 0 rgba(0, 0, 0, 0.3);
  --shadow-md: 0 4px 6px -1px rgba(0, 0, 0, 0.4);
  --shadow-lg: 0 10px 15px -3px rgba(0, 0, 0, 0.5);
  --shadow-xl: 0 20px 25px -5px rgba(0, 0, 0, 0.6);
  --primary-light: #1e1b4b;
}

*, *::before, *::after {
  box-sizing: border-box;
  margin: 0;
  padding: 0;
}

html {
  scroll-behavior: smooth;
  font-family: var(--font-sans);
  background-color: var(--bg-primary);
  color: var(--text-primary);
  line-height: 1.6;
  -webkit-font-smoothing: antialiased;
}

body {
  min-height: 100vh;
  display: flex;
  flex-direction: column;
  transition: background-color 0.25s ease, color 0.25s ease;
}

a {
  color: inherit;
  text-decoration: none;
}

button {
  font-family: inherit;
  cursor: pointer;
  border: none;
  background: none;
}

img, svg {
  display: block;
  max-width: 100%;
}

.container {
  width: 100%;
  max-width: 1200px;
  margin: 0 auto;
  padding: 0 24px;
}

/* Header & Navigation */
.header {
  position: sticky;
  top: 0;
  z-index: 100;
  background-color: var(--header-bg);
  backdrop-filter: blur(12px);
  -webkit-backdrop-filter: blur(12px);
  border-bottom: 1px solid var(--border-color);
  transition: background-color 0.25s ease, border-color 0.25s ease;
}

.header-inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  height: 72px;
}

.brand {
  display: flex;
  align-items: center;
  gap: 12px;
}

.brand-icon {
  width: 40px;
  height: 40px;
  border-radius: 12px;
  box-shadow: 0 4px 10px rgba(99, 102, 241, 0.3);
  object-fit: cover;
}

.brand-name {
  font-size: 1.35rem;
  font-weight: 900;
  letter-spacing: -0.02em;
  display: flex;
  align-items: center;
  gap: 3px;
}

.brand-name .punch {
  background: var(--gradient-brand);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
}

.nav {
  display: flex;
  align-items: center;
  gap: 28px;
}

.nav-link {
  font-size: 0.95rem;
  font-weight: 500;
  color: var(--text-secondary);
  transition: color 0.2s ease;
}

.nav-link:hover {
  color: var(--primary);
}

.header-actions {
  display: flex;
  align-items: center;
  gap: 14px;
}

.theme-toggle-btn {
  width: 40px;
  height: 40px;
  border-radius: var(--radius-full);
  display: flex;
  align-items: center;
  justify-content: center;
  background-color: var(--bg-tertiary);
  color: var(--text-secondary);
  border: 1px solid var(--border-color);
  transition: all 0.2s ease;
}

.theme-toggle-btn:hover {
  color: var(--text-primary);
  border-color: var(--primary);
}

.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
  padding: 10px 20px;
  border-radius: var(--radius-full);
  font-weight: 600;
  font-size: 0.95rem;
  transition: all 0.2s ease;
}

.btn-primary {
  background: var(--gradient-brand);
  color: #ffffff;
  box-shadow: 0 4px 14px rgba(99, 102, 241, 0.35);
}

.btn-primary:hover {
  opacity: 0.92;
  transform: translateY(-1px);
  box-shadow: 0 6px 20px rgba(99, 102, 241, 0.45);
}

.btn-secondary {
  background-color: var(--bg-tertiary);
  color: var(--text-primary);
  border: 1px solid var(--border-color);
}

.btn-secondary:hover {
  border-color: var(--primary);
  background-color: var(--primary-light);
  color: var(--primary);
}

.mobile-menu-btn {
  display: none;
  width: 40px;
  height: 40px;
  border-radius: var(--radius-sm);
  align-items: center;
  justify-content: center;
  color: var(--text-primary);
}

/* Hero Section */
.hero {
  padding: 70px 0 60px;
  position: relative;
  overflow: hidden;
}

.hero-glow {
  position: absolute;
  top: -120px;
  left: 50%;
  transform: translateX(-50%);
  width: 600px;
  height: 350px;
  background: radial-gradient(circle, rgba(99, 102, 241, 0.2) 0%, rgba(236, 72, 153, 0.1) 50%, transparent 70%);
  filter: blur(60px);
  z-index: -1;
  pointer-events: none;
}

.hero-grid {
  display: grid;
  grid-template-columns: 1.15fr 0.85fr;
  gap: 48px;
  align-items: center;
}

.hero-badge {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  padding: 6px 14px;
  border-radius: var(--radius-full);
  background: var(--bg-tertiary);
  border: 1px solid var(--border-color);
  font-size: 0.85rem;
  font-weight: 600;
  color: var(--primary);
  margin-bottom: 20px;
}

.hero-title {
  font-size: 3.25rem;
  line-height: 1.15;
  font-weight: 900;
  letter-spacing: -0.03em;
  margin-bottom: 20px;
}

.hero-title .highlight {
  background: var(--gradient-brand);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
}

.hero-description {
  font-size: 1.15rem;
  color: var(--text-secondary);
  line-height: 1.6;
  margin-bottom: 32px;
  max-width: 580px;
}

.hero-cta-group {
  display: flex;
  align-items: center;
  gap: 16px;
  flex-wrap: wrap;
  margin-bottom: 40px;
}

.google-play-btn {
  display: inline-flex;
  align-items: center;
  gap: 12px;
  padding: 10px 22px;
  border-radius: 14px;
  background-color: #000000;
  color: #ffffff;
  border: 1px solid rgba(255, 255, 255, 0.15);
  box-shadow: 0 4px 16px rgba(0, 0, 0, 0.2);
  transition: all 0.2s ease;
}

.google-play-btn:hover {
  transform: translateY(-2px);
  box-shadow: 0 8px 24px rgba(0, 0, 0, 0.35);
  border-color: rgba(255, 255, 255, 0.3);
}

.play-icon {
  width: 28px;
  height: 28px;
  flex-shrink: 0;
}

.play-text {
  text-align: left;
  line-height: 1.2;
}

.play-label {
  font-size: 0.7rem;
  text-transform: uppercase;
  letter-spacing: 0.05em;
  color: #cbd5e1;
}

.play-store {
  font-size: 1.15rem;
  font-weight: 700;
  color: #ffffff;
}

/* Stats Pill Bar */
.hero-stats {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 16px;
  padding: 20px;
  border-radius: var(--radius-lg);
  background-color: var(--bg-secondary);
  border: 1px solid var(--border-color);
}

.stat-item {
  display: flex;
  flex-direction: column;
}

.stat-number {
  font-size: 1.6rem;
  font-weight: 900;
  color: var(--text-primary);
  line-height: 1.2;
}

.stat-label {
  font-size: 0.8rem;
  font-weight: 500;
  color: var(--text-muted);
}

/* App Showcase Card */
.hero-visual {
  display: flex;
  justify-content: center;
}

.app-phone-card {
  width: 100%;
  max-width: 380px;
  border-radius: 28px;
  background-color: var(--card-bg);
  border: 1px solid var(--border-color);
  box-shadow: var(--shadow-xl);
  overflow: hidden;
  position: relative;
  transition: transform 0.3s ease;
}

.app-phone-card:hover {
  transform: translateY(-4px);
}

.card-topbar {
  background: var(--gradient-brand);
  padding: 24px 20px;
  color: #ffffff;
}

.card-app-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  margin-bottom: 16px;
}

.card-app-id {
  display: flex;
  align-items: center;
  gap: 10px;
}

.card-logo-mini {
  width: 34px;
  height: 34px;
  border-radius: 10px;
  background-color: #ffffff;
}

.card-app-title {
  font-weight: 800;
  font-size: 1.05rem;
  letter-spacing: 0.02em;
}

.card-tag {
  background: rgba(255, 255, 255, 0.2);
  padding: 4px 10px;
  border-radius: var(--radius-full);
  font-size: 0.75rem;
  font-weight: 600;
}

.card-hero-text h3 {
  font-size: 1.25rem;
  font-weight: 800;
  line-height: 1.3;
  margin-bottom: 6px;
}

.card-hero-text p {
  font-size: 0.85rem;
  opacity: 0.9;
}

.card-body {
  padding: 20px;
  display: flex;
  flex-direction: column;
  gap: 12px;
  background-color: var(--bg-secondary);
}

.mini-course-preview {
  background-color: var(--card-bg);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-md);
  padding: 14px;
  display: flex;
  flex-direction: column;
  gap: 6px;
}

.mini-badge-row {
  display: flex;
  align-items: center;
  justify-content: space-between;
}

.mini-badge {
  font-size: 0.7rem;
  font-weight: 700;
  padding: 2px 8px;
  border-radius: 6px;
  background-color: var(--primary-light);
  color: var(--primary);
}

.mini-course-preview h4 {
  font-size: 0.95rem;
  font-weight: 700;
  color: var(--text-primary);
}

.mini-course-preview p {
  font-size: 0.8rem;
  color: var(--text-muted);
}

.card-action-bar {
  padding: 14px 20px;
  background-color: var(--card-bg);
  border-top: 1px solid var(--border-color);
  display: flex;
  align-items: center;
  justify-content: space-between;
}

.card-action-bar .price {
  font-size: 1.1rem;
  font-weight: 800;
  color: var(--primary);
}

.card-action-bar .btn-sm {
  font-size: 0.85rem;
  padding: 6px 14px;
}

/* Sections Common */
.section {
  padding: 80px 0;
}

.section-alt {
  background-color: var(--bg-secondary);
}

.section-header {
  text-align: center;
  max-width: 680px;
  margin: 0 auto 50px;
}

.section-subtitle {
  text-transform: uppercase;
  font-size: 0.8rem;
  font-weight: 800;
  letter-spacing: 0.1em;
  color: var(--primary);
  margin-bottom: 10px;
}

.section-title {
  font-size: 2.25rem;
  font-weight: 800;
  letter-spacing: -0.02em;
  margin-bottom: 14px;
  color: var(--text-primary);
}

.section-description {
  font-size: 1.05rem;
  color: var(--text-secondary);
}

/* Features Grid */
.features-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 28px;
}

.feature-card {
  background-color: var(--card-bg);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-lg);
  padding: 30px;
  transition: all 0.25s ease;
  position: relative;
}

.feature-card:hover {
  transform: translateY(-4px);
  border-color: var(--primary);
  box-shadow: var(--shadow-lg);
}

.feature-icon-wrapper {
  width: 52px;
  height: 52px;
  border-radius: var(--radius-md);
  background: var(--bg-tertiary);
  color: var(--primary);
  display: flex;
  align-items: center;
  justify-content: center;
  margin-bottom: 20px;
  font-size: 1.5rem;
  border: 1px solid var(--border-color);
}

.feature-card h3 {
  font-size: 1.25rem;
  font-weight: 700;
  margin-bottom: 10px;
  color: var(--text-primary);
}

.feature-card p {
  font-size: 0.95rem;
  color: var(--text-secondary);
  line-height: 1.6;
}

/* Categories Filter */
.categories-filter {
  display: flex;
  justify-content: center;
  gap: 10px;
  margin-bottom: 40px;
  flex-wrap: wrap;
}

.filter-btn {
  padding: 8px 18px;
  border-radius: var(--radius-full);
  background-color: var(--bg-tertiary);
  border: 1px solid var(--border-color);
  color: var(--text-secondary);
  font-size: 0.9rem;
  font-weight: 600;
  transition: all 0.2s ease;
}

.filter-btn:hover {
  border-color: var(--primary);
  color: var(--text-primary);
}

.filter-btn.active {
  background-color: var(--primary);
  color: #ffffff;
  border-color: var(--primary);
}

/* Course Grid */
.courses-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(360px, 1fr));
  gap: 28px;
}

.course-card {
  background-color: var(--card-bg);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-lg);
  overflow: hidden;
  display: flex;
  flex-direction: column;
  transition: all 0.25s ease;
  position: relative;
}

.course-card:hover {
  transform: translateY(-4px);
  box-shadow: var(--shadow-lg);
  border-color: var(--primary);
}

.course-accent-bar {
  height: 5px;
  background: var(--gradient-brand);
}

.course-card-content {
  padding: 24px;
  display: flex;
  flex-direction: column;
  flex: 1;
}

.course-meta-top {
  display: flex;
  align-items: center;
  justify-content: space-between;
  margin-bottom: 12px;
}

.category-tag {
  font-size: 0.75rem;
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: 0.05em;
  color: var(--primary);
}

.level-tag {
  font-size: 0.75rem;
  font-weight: 600;
  background-color: var(--bg-tertiary);
  color: var(--text-muted);
  padding: 3px 10px;
  border-radius: var(--radius-full);
  border: 1px solid var(--border-color);
}

.course-title {
  font-size: 1.3rem;
  font-weight: 800;
  color: var(--text-primary);
  margin-bottom: 8px;
  line-height: 1.3;
}

.course-description {
  font-size: 0.9rem;
  color: var(--text-secondary);
  line-height: 1.5;
  margin-bottom: 16px;
  flex: 1;
}

.course-stats-bar {
  display: flex;
  align-items: center;
  gap: 16px;
  padding: 12px 0;
  border-top: 1px solid var(--border-color);
  border-bottom: 1px solid var(--border-color);
  font-size: 0.85rem;
  color: var(--text-muted);
  margin-bottom: 18px;
}

.course-stat {
  display: flex;
  align-items: center;
  gap: 6px;
}

.course-card-footer {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 12px;
}

.course-price-box {
  display: flex;
  flex-direction: column;
}

.price-label {
  font-size: 0.7rem;
  text-transform: uppercase;
  color: var(--text-muted);
}

.price-value {
  font-size: 1.25rem;
  font-weight: 900;
  color: var(--text-primary);
}

.course-actions {
  display: flex;
  gap: 8px;
}

.btn-syllabus {
  font-size: 0.85rem;
  padding: 8px 14px;
}

/* Curriculum Preview Section */
.curriculum-viewer {
  background-color: var(--card-bg);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-lg);
  overflow: hidden;
  box-shadow: var(--shadow-md);
}

.curriculum-selector-bar {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 18px 24px;
  background-color: var(--bg-tertiary);
  border-bottom: 1px solid var(--border-color);
  flex-wrap: wrap;
  gap: 16px;
}

.course-dropdown-select {
  padding: 10px 16px;
  border-radius: var(--radius-md);
  background-color: var(--card-bg);
  color: var(--text-primary);
  border: 1px solid var(--border-color);
  font-size: 0.95rem;
  font-weight: 600;
  min-width: 280px;
  cursor: pointer;
}

.module-search-input {
  padding: 10px 16px;
  border-radius: var(--radius-md);
  background-color: var(--card-bg);
  color: var(--text-primary);
  border: 1px solid var(--border-color);
  font-size: 0.9rem;
  min-width: 220px;
}

.curriculum-modules-list {
  max-height: 480px;
  overflow-y: auto;
  padding: 16px 24px;
  display: flex;
  flex-direction: column;
  gap: 8px;
}

.module-item {
  display: flex;
  align-items: center;
  gap: 16px;
  padding: 12px 16px;
  border-radius: var(--radius-md);
  background-color: var(--bg-secondary);
  border: 1px solid var(--border-color);
  transition: all 0.2s ease;
}

.module-item:hover {
  border-color: var(--primary);
  background-color: var(--card-bg);
}

.module-number {
  width: 32px;
  height: 32px;
  border-radius: var(--radius-full);
  background-color: var(--bg-tertiary);
  color: var(--text-primary);
  font-size: 0.85rem;
  font-weight: 700;
  display: flex;
  align-items: center;
  justify-content: center;
  flex-shrink: 0;
}

.module-title {
  font-size: 0.95rem;
  font-weight: 600;
  color: var(--text-primary);
  flex: 1;
}

.module-badge-free {
  font-size: 0.7rem;
  font-weight: 700;
  text-transform: uppercase;
  padding: 3px 8px;
  border-radius: 4px;
  background-color: #10b981;
  color: #ffffff;
}

/* Interactive Quiz Section */
.quiz-container {
  max-width: 780px;
  margin: 0 auto;
  background-color: var(--card-bg);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-lg);
  padding: 36px;
  box-shadow: var(--shadow-lg);
}

.quiz-badge-bar {
  display: flex;
  align-items: center;
  justify-content: space-between;
  margin-bottom: 20px;
}

.quiz-course-tag {
  font-size: 0.85rem;
  font-weight: 700;
  color: var(--primary);
}

.quiz-question-title {
  font-size: 1.25rem;
  font-weight: 700;
  color: var(--text-primary);
  line-height: 1.4;
  margin-bottom: 24px;
}

.quiz-options-list {
  display: flex;
  flex-direction: column;
  gap: 12px;
  margin-bottom: 24px;
}

.quiz-option-btn {
  text-align: left;
  padding: 14px 20px;
  border-radius: var(--radius-md);
  background-color: var(--bg-secondary);
  border: 1px solid var(--border-color);
  color: var(--text-primary);
  font-size: 0.95rem;
  font-weight: 500;
  display: flex;
  align-items: flex-start;
  gap: 12px;
  transition: all 0.2s ease;
}

.quiz-option-btn:hover:not(:disabled) {
  border-color: var(--primary);
  background-color: var(--primary-light);
  color: var(--primary);
}

.quiz-option-btn.selected-correct {
  background-color: #ecfdf5;
  border-color: #10b981;
  color: #065f46;
}

.quiz-option-btn.selected-wrong {
  background-color: #fef2f2;
  border-color: #ef4444;
  color: #991b1b;
}

[data-theme="dark"] .quiz-option-btn.selected-correct {
  background-color: #064e3b;
  border-color: #059669;
  color: #a7f3d0;
}

[data-theme="dark"] .quiz-option-btn.selected-wrong {
  background-color: #7f1d1d;
  border-color: #dc2626;
  color: #fecaca;
}

.quiz-explanation-box {
  padding: 16px 20px;
  border-radius: var(--radius-md);
  background-color: var(--bg-tertiary);
  border-left: 4px solid var(--primary);
  font-size: 0.9rem;
  color: var(--text-secondary);
  line-height: 1.5;
  display: none;
}

.quiz-footer-actions {
  display: flex;
  align-items: center;
  justify-content: space-between;
  margin-top: 24px;
}

/* FAQ Section */
.faq-grid {
  max-width: 800px;
  margin: 0 auto;
  display: flex;
  flex-direction: column;
  gap: 16px;
}

.faq-item {
  background-color: var(--card-bg);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-md);
  overflow: hidden;
  transition: border-color 0.2s ease;
}

.faq-item:hover {
  border-color: var(--primary);
}

.faq-question {
  width: 100%;
  padding: 20px 24px;
  text-align: left;
  display: flex;
  align-items: center;
  justify-content: space-between;
  font-size: 1.05rem;
  font-weight: 700;
  color: var(--text-primary);
  gap: 16px;
}

.faq-icon {
  font-size: 1.2rem;
  transition: transform 0.25s ease;
}

.faq-item.active .faq-icon {
  transform: rotate(180deg);
}

.faq-answer {
  max-height: 0;
  overflow: hidden;
  transition: max-height 0.3s ease, padding 0.3s ease;
  padding: 0 24px;
  color: var(--text-secondary);
  font-size: 0.95rem;
  line-height: 1.6;
}

.faq-item.active .faq-answer {
  max-height: 300px;
  padding-bottom: 20px;
}

/* Download CTA Section */
.cta-section {
  padding: 90px 0;
  position: relative;
  overflow: hidden;
}

.cta-box {
  background: var(--gradient-brand);
  border-radius: 28px;
  padding: 60px 48px;
  color: #ffffff;
  text-align: center;
  position: relative;
  box-shadow: 0 20px 40px rgba(99, 102, 241, 0.3);
}

.cta-title {
  font-size: 2.75rem;
  font-weight: 900;
  line-height: 1.2;
  margin-bottom: 16px;
  letter-spacing: -0.02em;
}

.cta-description {
  font-size: 1.15rem;
  max-width: 600px;
  margin: 0 auto 36px;
  opacity: 0.92;
}

.cta-btn-wrap {
  display: flex;
  justify-content: center;
  gap: 16px;
  flex-wrap: wrap;
}

/* Footer */
.footer {
  background-color: var(--bg-tertiary);
  border-top: 1px solid var(--border-color);
  padding: 60px 0 30px;
  margin-top: auto;
}

.footer-grid {
  display: grid;
  grid-template-columns: 1.5fr repeat(3, 1fr);
  gap: 40px;
  margin-bottom: 40px;
}

.footer-brand p {
  color: var(--text-secondary);
  font-size: 0.9rem;
  margin-top: 12px;
  max-width: 320px;
}

.footer-heading {
  font-size: 0.95rem;
  font-weight: 700;
  color: var(--text-primary);
  margin-bottom: 16px;
  text-transform: uppercase;
  letter-spacing: 0.05em;
}

.footer-links {
  list-style: none;
  display: flex;
  flex-direction: column;
  gap: 10px;
}

.footer-links a {
  font-size: 0.9rem;
  color: var(--text-secondary);
  transition: color 0.2s ease;
}

.footer-links a:hover {
  color: var(--primary);
}

.footer-bottom {
  padding-top: 24px;
  border-top: 1px solid var(--border-color);
  display: flex;
  align-items: center;
  justify-content: space-between;
  font-size: 0.85rem;
  color: var(--text-muted);
  flex-wrap: wrap;
  gap: 12px;
}

/* Syllabus Modal */
.modal-overlay {
  position: fixed;
  inset: 0;
  background-color: rgba(0, 0, 0, 0.65);
  backdrop-filter: blur(4px);
  z-index: 200;
  display: none;
  align-items: center;
  justify-content: center;
  padding: 20px;
}

.modal-overlay.open {
  display: flex;
}

.modal-window {
  width: 100%;
  max-width: 680px;
  max-height: 85vh;
  background-color: var(--card-bg);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-lg);
  display: flex;
  flex-direction: column;
  box-shadow: var(--shadow-xl);
  overflow: hidden;
}

.modal-header {
  padding: 20px 24px;
  border-bottom: 1px solid var(--border-color);
  display: flex;
  align-items: center;
  justify-content: space-between;
}

.modal-title {
  font-size: 1.25rem;
  font-weight: 800;
  color: var(--text-primary);
}

.modal-close-btn {
  font-size: 1.5rem;
  line-height: 1;
  color: var(--text-muted);
  transition: color 0.2s ease;
}

.modal-close-btn:hover {
  color: var(--text-primary);
}

.modal-body {
  padding: 20px 24px;
  overflow-y: auto;
  flex: 1;
}

/* Legal Pages (Privacy Policy, Terms) */
.legal-page {
  padding: 60px 0 80px;
}

.legal-header {
  margin-bottom: 40px;
  padding-bottom: 20px;
  border-bottom: 1px solid var(--border-color);
}

.legal-header h1 {
  font-size: 2.5rem;
  font-weight: 900;
  margin-bottom: 12px;
  color: var(--text-primary);
}

.legal-meta {
  font-size: 0.9rem;
  color: var(--text-muted);
}

.legal-content {
  font-size: 1rem;
  line-height: 1.75;
  color: var(--text-secondary);
}

.legal-content h2 {
  font-size: 1.4rem;
  font-weight: 800;
  color: var(--text-primary);
  margin: 36px 0 14px;
}

.legal-content h3 {
  font-size: 1.15rem;
  font-weight: 700;
  color: var(--text-primary);
  margin: 24px 0 10px;
}

.legal-content p {
  margin-bottom: 16px;
}

.legal-content ul, .legal-content ol {
  margin: 12px 0 20px 24px;
}

.legal-content li {
  margin-bottom: 8px;
}

.legal-callout {
  background-color: var(--bg-tertiary);
  border-left: 4px solid var(--primary);
  border-radius: var(--radius-sm);
  padding: 16px 20px;
  margin: 24px 0;
}

/* Responsive */
@media (max-width: 992px) {
  .hero-grid {
    grid-template-columns: 1fr;
    text-align: center;
  }
  .hero-description {
    margin-left: auto;
    margin-right: auto;
  }
  .hero-cta-group {
    justify-content: center;
  }
  .hero-stats {
    grid-template-columns: repeat(2, 1fr);
  }
  .features-grid {
    grid-template-columns: repeat(2, 1fr);
  }
  .footer-grid {
    grid-template-columns: 1fr 1fr;
  }
}

@media (max-width: 768px) {
  .hero-title {
    font-size: 2.35rem;
  }
  .nav {
    display: none;
  }
  .mobile-menu-btn {
    display: flex;
  }
  .features-grid {
    grid-template-columns: 1fr;
  }
  .courses-grid {
    grid-template-columns: 1fr;
  }
  .curriculum-selector-bar {
    flex-direction: column;
    align-items: stretch;
  }
  .course-dropdown-select, .module-search-input {
    width: 100%;
  }
  .footer-grid {
    grid-template-columns: 1fr;
  }
  .cta-title {
    font-size: 2rem;
  }
}