/* ============================================
   Apple-Inspired CSS Variables & Root Styles
   ============================================ */
:root {
  /* Light Theme Colors - Apple Style */
  --bg-primary: #ffffff;
  --bg-secondary: #f5f5f7;
  --bg-tertiary: #e8e8ed;
  --text-primary: #1d1d1f;
  --text-secondary: #86868b;
  --text-tertiary: #a1a1a6;

  /* Accent Colors - Refined Purple/Blue */
  --accent-primary: #0071e3;
  --accent-secondary: #5856d6;
  --accent-hover: #0077ed;
  --success: #34c759;
  --warning: #ff9500;
  --danger: #ff3b30;

  /* Card & Border */
  --card-bg: #ffffff;
  --border-color: #d2d2d7;
  --shadow-sm: 0 1px 3px 0 rgba(0, 0, 0, 0.04);
  --shadow-md: 0 2px 8px 0 rgba(0, 0, 0, 0.08);
  --shadow-lg: 0 4px 16px 0 rgba(0, 0, 0, 0.12);
  --shadow-xl: 0 8px 32px 0 rgba(0, 0, 0, 0.16);

  /* Spacing */
  --spacing-xs: 0.5rem;
  --spacing-sm: 1rem;
  --spacing-md: 1.5rem;
  --spacing-lg: 2rem;
  --spacing-xl: 3rem;
  --spacing-2xl: 4rem;

  /* Border Radius - Apple Style */
  --radius-sm: 0.5rem;
  --radius-md: 0.75rem;
  --radius-lg: 1rem;
  --radius-xl: 1.25rem;

  /* Transitions - Smooth Apple-like */
  --transition-fast: 200ms cubic-bezier(0.4, 0, 0.2, 1);
  --transition-base: 300ms cubic-bezier(0.4, 0, 0.2, 1);
  --transition-slow: 400ms cubic-bezier(0.4, 0, 0.2, 1);
}

[data-theme="dark"] {
  --bg-primary: #000000;
  --bg-secondary: #1c1c1e;
  --bg-tertiary: #2c2c2e;
  --text-primary: #f5f5f7;
  --text-secondary: #a1a1a6;
  --text-tertiary: #6e6e73;

  --card-bg: #1c1c1e;
  --border-color: #38383a;
  --shadow-sm: 0 1px 3px 0 rgba(0, 0, 0, 0.3);
  --shadow-md: 0 2px 8px 0 rgba(0, 0, 0, 0.4);
  --shadow-lg: 0 4px 16px 0 rgba(0, 0, 0, 0.5);
  --shadow-xl: 0 8px 32px 0 rgba(0, 0, 0, 0.6);
}

/* ============================================
   Reset & Base Styles
   ============================================ */
* {
  margin: 0;
  padding: 0;
  box-sizing: border-box;
}

html {
  scroll-behavior: smooth;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
}

body {
  font-family: -apple-system, BlinkMacSystemFont, "Inter", "SF Pro Display",
    "Segoe UI", Roboto, sans-serif;
  background: var(--bg-primary);
  color: var(--text-primary);
  line-height: 1.47059;
  font-weight: 400;
  letter-spacing: -0.022em;
  transition: background-color var(--transition-base),
    color var(--transition-base);
}

.container {
  max-width: 1200px;
  margin: 0 auto;
  padding: 0 var(--spacing-md);
}

/* ============================================
   Navigation - Apple Style
   ============================================ */
.navbar {
  background: rgba(255, 255, 255, 0.8);
  backdrop-filter: saturate(180%) blur(20px);
  -webkit-backdrop-filter: saturate(180%) blur(20px);
  border-bottom: 1px solid var(--border-color);
  position: sticky;
  top: 0;
  z-index: 1000;
  transition: all var(--transition-base);
}

[data-theme="dark"] .navbar {
  background: rgba(28, 28, 30, 0.8);
}

.navbar .container {
  display: flex;
  justify-content: space-between;
  align-items: center;
  padding: 1rem var(--spacing-md);
  min-height: 44px;
}

.nav-brand {
  display: flex;
  align-items: center;
  gap: var(--spacing-sm);
}

.nav-brand h1 {
  font-size: 1.25rem;
  font-weight: 600;
  letter-spacing: -0.01em;
  background: linear-gradient(
    90deg,
    var(--accent-primary),
    var(--accent-secondary)
  );
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}

.badge {
  background: var(--accent-primary);
  color: white;
  padding: 0.2rem 0.6rem;
  border-radius: 0.4rem;
  font-size: 0.75rem;
  font-weight: 600;
  letter-spacing: 0.02em;
}

.nav-links {
  display: flex;
  gap: var(--spacing-lg);
  align-items: center;
}

.nav-link {
  text-decoration: none;
  color: var(--text-primary);
  font-weight: 400;
  font-size: 0.875rem;
  transition: color var(--transition-fast);
  padding: 0.5rem 0.75rem;
  border-radius: var(--radius-md);
  position: relative;
}

.nav-link::after {
  content: "";
  position: absolute;
  bottom: 0;
  left: 50%;
  transform: translateX(-50%);
  width: 0;
  height: 2px;
  background: var(--accent-primary);
  transition: width var(--transition-base);
}

.nav-link:hover::after,
.nav-link.active::after {
  width: calc(100% - 1.5rem);
}

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

.nav-actions {
  display: flex;
  align-items: center;
  gap: 0.75rem;
}

.search-toggle,
.github-link {
  background: var(--bg-secondary);
  border: none;
  border-radius: var(--radius-md);
  padding: 0.5rem 0.75rem;
  cursor: pointer;
  transition: all var(--transition-fast);
  display: flex;
  align-items: center;
  justify-content: center;
  color: var(--text-primary);
  text-decoration: none;
}

.search-toggle:hover,
.github-link:hover {
  background: var(--bg-tertiary);
  transform: scale(1.05);
}

.hamburger {
  display: none;
  flex-direction: column;
  gap: 4px;
  background: transparent;
  border: none;
  cursor: pointer;
  padding: 0.5rem;
}

.hamburger span {
  width: 24px;
  height: 2px;
  background: var(--text-primary);
  transition: all var(--transition-fast);
  border-radius: 2px;
}

.hamburger.active span:nth-child(1) {
  transform: rotate(45deg) translate(5px, 5px);
}

.hamburger.active span:nth-child(2) {
  opacity: 0;
}

.hamburger.active span:nth-child(3) {
  transform: rotate(-45deg) translate(7px, -6px);
}

.theme-toggle {
  background: var(--bg-secondary);
  border: none;
  border-radius: var(--radius-md);
  padding: 0.5rem 0.75rem;
  cursor: pointer;
  transition: all var(--transition-fast);
  display: flex;
  align-items: center;
  justify-content: center;
  color: var(--text-primary);
}

.theme-toggle:hover {
  background: var(--bg-tertiary);
  transform: scale(1.05);
}

.theme-icon {
  width: 20px;
  height: 20px;
  transition: opacity var(--transition-fast);
}

[data-theme="light"] .theme-icon.moon {
  display: none;
}

[data-theme="dark"] .theme-icon.sun {
  display: none;
}

/* ============================================
   Search Overlay
   ============================================ */
.search-overlay {
  display: none;
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  bottom: 0;
  background: rgba(0, 0, 0, 0.5);
  backdrop-filter: blur(10px);
  z-index: 1000;
  opacity: 0;
  transition: opacity var(--transition-base);
}

.search-overlay.active {
  display: flex;
  opacity: 1;
  animation: fadeIn 0.3s ease;
}

.search-container {
  width: 100%;
  max-width: 700px;
  margin: 4rem auto;
  background: var(--card-bg);
  border-radius: var(--radius-xl);
  box-shadow: var(--shadow-xl);
  overflow: hidden;
  animation: slideDown 0.3s ease;
}

@keyframes slideDown {
  from {
    transform: translateY(-2rem);
    opacity: 0;
  }
  to {
    transform: translateY(0);
    opacity: 1;
  }
}

.search-header {
  display: flex;
  align-items: center;
  gap: 1rem;
  padding: 1.5rem;
  border-bottom: 1px solid var(--border-color);
}

.search-input {
  flex: 1;
  font-size: 1.125rem;
  padding: 0.75rem;
  border: none;
  background: var(--bg-secondary);
  border-radius: var(--radius-md);
  color: var(--text-primary);
  font-family: inherit;
  transition: all var(--transition-fast);
}

.search-input:focus {
  outline: none;
  background: var(--bg-tertiary);
  box-shadow: 0 0 0 3px var(--accent-primary-alpha);
}

.search-close {
  background: transparent;
  border: none;
  cursor: pointer;
  color: var(--text-secondary);
  padding: 0.5rem;
  display: flex;
  align-items: center;
  justify-content: center;
  border-radius: var(--radius-md);
  transition: all var(--transition-fast);
}

.search-close:hover {
  background: var(--bg-secondary);
  color: var(--text-primary);
}

.search-filters {
  display: flex;
  gap: 0.5rem;
  padding: 1rem 1.5rem;
  border-bottom: 1px solid var(--border-color);
  overflow-x: auto;
}

.filter-btn {
  padding: 0.5rem 1rem;
  border: 1px solid var(--border-color);
  background: var(--bg-secondary);
  border-radius: var(--radius-full);
  font-size: 0.875rem;
  font-weight: 500;
  cursor: pointer;
  transition: all var(--transition-fast);
  white-space: nowrap;
  color: var(--text-primary);
}

.filter-btn:hover {
  background: var(--bg-tertiary);
  border-color: var(--accent-primary);
}

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

.search-results {
  max-height: 60vh;
  overflow-y: auto;
  padding: 1rem;
}

.search-empty {
  text-align: center;
  padding: 3rem 1rem;
  color: var(--text-secondary);
}

.search-empty svg {
  margin-bottom: 1rem;
  opacity: 0.5;
}

.search-result-item {
  padding: 1rem;
  border-radius: var(--radius-md);
  background: var(--bg-secondary);
  margin-bottom: 0.75rem;
  cursor: pointer;
  transition: all var(--transition-fast);
  border: 1px solid transparent;
}

.search-result-item:hover {
  background: var(--bg-tertiary);
  border-color: var(--accent-primary);
  transform: translateX(4px);
}

.search-result-header {
  display: flex;
  justify-content: space-between;
  align-items: start;
  margin-bottom: 0.5rem;
}

.search-result-title {
  font-weight: 600;
  color: var(--text-primary);
  font-size: 1rem;
  margin: 0;
}

.search-result-badge {
  padding: 0.25rem 0.75rem;
  background: var(--accent-primary);
  color: white;
  border-radius: var(--radius-full);
  font-size: 0.75rem;
  font-weight: 600;
}

.search-result-path {
  color: var(--text-secondary);
  font-size: 0.875rem;
  margin-bottom: 0.5rem;
}

.search-result-snippet {
  color: var(--text-secondary);
  font-size: 0.875rem;
  line-height: 1.5;
}

.search-result-snippet mark {
  background: var(--accent-primary-alpha);
  color: var(--accent-primary);
  padding: 0.125rem 0.25rem;
  border-radius: 0.25rem;
}

/* ============================================
   Hero Section - Apple Style
   ============================================ */
.hero {
  background: linear-gradient(
    135deg,
    var(--accent-primary) 0%,
    var(--accent-secondary) 100%
  );
  color: white;
  padding: var(--spacing-2xl) 0;
  text-align: center;
  position: relative;
  overflow: hidden;
}

.hero::before {
  content: "";
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  bottom: 0;
  background: radial-gradient(
    circle at 30% 50%,
    rgba(255, 255, 255, 0.1),
    transparent 50%
  );
}

.hero-content {
  padding: var(--spacing-xl) 0;
  position: relative;
  z-index: 1;
}

.hero-title {
  font-size: 3.5rem;
  font-weight: 700;
  letter-spacing: -0.03em;
  margin-bottom: var(--spacing-sm);
  line-height: 1.08349;
}

.hero-subtitle {
  font-size: 1.25rem;
  opacity: 0.95;
  margin-bottom: var(--spacing-lg);
  font-weight: 400;
  letter-spacing: -0.01em;
}

.hero-stats {
  display: flex;
  justify-content: center;
  gap: var(--spacing-2xl);
  margin: var(--spacing-xl) 0;
}

.stat {
  display: flex;
  flex-direction: column;
  align-items: center;
}

.stat-number {
  font-size: 3rem;
  font-weight: 600;
  line-height: 1;
  letter-spacing: -0.02em;
}

.stat-label {
  font-size: 0.875rem;
  opacity: 0.9;
  text-transform: capitalize;
  letter-spacing: 0.01em;
  margin-top: 0.25rem;
}

.hero-cta {
  display: flex;
  gap: var(--spacing-md);
  justify-content: center;
  margin-top: var(--spacing-xl);
}

/* ============================================
   Buttons - Apple Style
   ============================================ */
.btn {
  padding: 0.75rem 1.5rem;
  border-radius: var(--radius-lg);
  font-weight: 500;
  font-size: 1rem;
  text-decoration: none;
  display: inline-block;
  transition: all var(--transition-fast);
  cursor: pointer;
  border: none;
  letter-spacing: -0.01em;
}

.btn-primary {
  background: white;
  color: var(--accent-primary);
}

.btn-primary:hover {
  transform: scale(1.02);
  box-shadow: var(--shadow-lg);
}

.btn-secondary {
  background: rgba(255, 255, 255, 0.15);
  color: white;
  border: 1px solid rgba(255, 255, 255, 0.3);
  backdrop-filter: blur(10px);
}

.btn-secondary:hover {
  background: rgba(255, 255, 255, 0.25);
  transform: scale(1.02);
}

.btn-outline {
  background: transparent;
  color: var(--accent-primary);
  border: 1px solid var(--accent-primary);
}

.btn-outline:hover {
  background: var(--accent-primary);
  color: white;
  transform: translateY(-2px);
  box-shadow: var(--shadow-md);
}

.btn-small {
  padding: 0.5rem 1rem;
  font-size: 0.875rem;
  display: inline-block;
}

/* ============================================
   Features Section
   ============================================ */
.features {
  padding: var(--spacing-2xl) 0;
  background: var(--bg-secondary);
}

.section-title {
  text-align: center;
  font-size: 2.5rem;
  font-weight: 600;
  letter-spacing: -0.02em;
  margin-bottom: var(--spacing-xl);
  color: var(--text-primary);
}

.section-subtitle {
  text-align: center;
  font-size: 1.125rem;
  color: var(--text-secondary);
  margin-bottom: var(--spacing-lg);
  letter-spacing: -0.01em;
}

.features-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
  gap: var(--spacing-lg);
}

.feature-card {
  background: var(--card-bg);
  padding: var(--spacing-lg);
  border-radius: var(--radius-xl);
  box-shadow: var(--shadow-md);
  transition: all var(--transition-base);
  border: 1px solid var(--border-color);
}

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

.feature-icon {
  font-size: 2rem;
  margin-bottom: var(--spacing-md);
  color: var(--accent-primary);
}

.feature-icon svg {
  width: 32px;
  height: 32px;
  color: var(--accent-primary);
}

.feature-card h3 {
  font-size: 1.25rem;
  font-weight: 600;
  margin-bottom: var(--spacing-sm);
  letter-spacing: -0.01em;
  color: var(--text-primary);
}

.feature-card p {
  color: var(--text-secondary);
  line-height: 1.5;
  font-size: 0.9375rem;
}

/* ============================================
   Subjects Section
   ============================================ */
.subjects {
  padding: var(--spacing-2xl) 0;
}

.subjects-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
  gap: var(--spacing-lg);
}

.subject-card {
  background: var(--card-bg);
  border-radius: var(--radius-xl);
  padding: var(--spacing-lg);
  box-shadow: var(--shadow-md);
  transition: all var(--transition-base);
  border: 1px solid var(--border-color);
  display: flex;
  flex-direction: column;
}

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

.subject-header {
  display: flex;
  justify-content: space-between;
  align-items: start;
  margin-bottom: var(--spacing-md);
}

.subject-header h3 {
  font-size: 1.5rem;
  font-weight: 600;
  letter-spacing: -0.02em;
  color: var(--text-primary);
}

.subject-code {
  background: var(--bg-secondary);
  padding: 0.3rem 0.75rem;
  border-radius: var(--radius-md);
  font-size: 0.8125rem;
  font-weight: 500;
  color: var(--text-secondary);
}

.resource-list {
  list-style: none;
  margin-bottom: var(--spacing-md);
}

.resource-list li {
  padding: 0.75rem 0;
  color: var(--text-secondary);
  border-bottom: 1px solid var(--border-color);
  font-size: 0.9375rem;
}

.resource-list li:last-child {
  border-bottom: none;
}

.subject-tags {
  display: flex;
  flex-wrap: wrap;
  gap: var(--spacing-xs);
  margin-bottom: var(--spacing-md);
}

.tag {
  background: linear-gradient(
    135deg,
    var(--accent-primary),
    var(--accent-secondary)
  );
  color: white;
  padding: 0.3rem 0.75rem;
  border-radius: 0.5rem;
  font-size: 0.75rem;
  font-weight: 500;
  letter-spacing: 0.01em;
}

.subject-card .btn {
  margin-top: auto;
  width: 100%;
  text-align: center;
}

/* ============================================
   Emergency Section
   ============================================ */
.emergency {
  padding: var(--spacing-2xl) 0;
  background: var(--bg-secondary);
}

.emergency-header {
  text-align: center;
  margin-bottom: var(--spacing-xl);
}

.emergency-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
  gap: var(--spacing-md);
}

.emergency-card {
  background: linear-gradient(
    135deg,
    var(--accent-primary),
    var(--accent-secondary)
  );
  color: white;
  padding: var(--spacing-lg);
  border-radius: var(--radius-xl);
  box-shadow: var(--shadow-lg);
  transition: all var(--transition-base);
  cursor: pointer;
  text-decoration: none;
  display: block;
}

.emergency-card:hover {
  transform: translateY(-4px) scale(1.02);
  box-shadow: var(--shadow-xl);
}

.emergency-card h3 {
  font-size: 1.25rem;
  font-weight: 600;
  margin-bottom: var(--spacing-sm);
  letter-spacing: -0.01em;
  color: white;
}

.emergency-card p {
  opacity: 0.95;
  margin-bottom: var(--spacing-md);
  font-size: 0.875rem;
  line-height: 1.5;
  color: white;
}

.emergency-card .btn {
  background: white;
  color: var(--accent-primary);
  width: 100%;
  text-align: center;
}

/* ============================================
   About Section
   ============================================ */
.about {
  padding: var(--spacing-2xl) 0;
}

.about-content {
  max-width: 800px;
  margin: 0 auto;
}

.about-text h3 {
  font-size: 1.75rem;
  font-weight: 600;
  margin: var(--spacing-lg) 0 var(--spacing-md);
  letter-spacing: -0.02em;
  color: var(--text-primary);
}

.about-text ul {
  margin-left: var(--spacing-lg);
  margin-bottom: var(--spacing-md);
  color: var(--text-secondary);
}

.about-text li {
  margin-bottom: var(--spacing-xs);
  line-height: 1.5;
}

.ai-models {
  display: flex;
  flex-wrap: wrap;
  gap: var(--spacing-sm);
  margin: var(--spacing-md) 0;
}

.ai-badge {
  background: linear-gradient(
    135deg,
    var(--accent-primary),
    var(--accent-secondary)
  );
  color: white;
  padding: 0.5rem 1rem;
  border-radius: var(--radius-lg);
  font-size: 0.875rem;
  font-weight: 500;
}

.disclaimer {
  background: var(--bg-secondary);
  padding: var(--spacing-lg);
  border-radius: var(--radius-xl);
  border-left: 4px solid var(--warning);
  margin-top: var(--spacing-xl);
}

.disclaimer h4 {
  margin-bottom: var(--spacing-sm);
  color: var(--text-primary);
  font-weight: 600;
}

.disclaimer p {
  color: var(--text-secondary);
  line-height: 1.5;
}

/* ============================================
   Footer
   ============================================ */
.footer {
  background: var(--bg-secondary);
  padding: var(--spacing-xl) 0 var(--spacing-md);
  border-top: 1px solid var(--border-color);
}

.footer-content {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
  gap: var(--spacing-xl);
  margin-bottom: var(--spacing-lg);
}

.footer-section h3,
.footer-section h4 {
  margin-bottom: var(--spacing-md);
  color: var(--text-primary);
  font-weight: 600;
  letter-spacing: -0.01em;
}

.footer-section p {
  color: var(--text-secondary);
  margin-bottom: var(--spacing-sm);
  line-height: 1.5;
}

.footer-section ul {
  list-style: none;
}

.footer-section ul li {
  margin-bottom: var(--spacing-xs);
}

.footer-section a {
  color: var(--text-secondary);
  text-decoration: none;
  transition: color var(--transition-fast);
  font-size: 0.9375rem;
}

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

.footer-stats {
  margin-top: var(--spacing-md);
}

.footer-bottom {
  text-align: center;
  padding-top: var(--spacing-lg);
  border-top: 1px solid var(--border-color);
  color: var(--text-tertiary);
  font-size: 0.875rem;
}

.footer-bottom p {
  margin: var(--spacing-xs) 0;
}

/* ============================================
   Modal - Apple Style
   ============================================ */
.modal {
  display: none;
  position: fixed;
  z-index: 2000;
  left: 0;
  top: 0;
  width: 100%;
  height: 100%;
  overflow: auto;
  background-color: rgba(0, 0, 0, 0.6);
  backdrop-filter: blur(10px);
  -webkit-backdrop-filter: blur(10px);
  animation: fadeIn 0.2s ease;
}

@keyframes fadeIn {
  from {
    opacity: 0;
  }
  to {
    opacity: 1;
  }
}

.modal-content {
  background-color: var(--card-bg);
  margin: 3% auto;
  padding: 0;
  border: 1px solid var(--border-color);
  border-radius: var(--radius-xl);
  width: 90%;
  max-width: 900px;
  max-height: 85vh;
  box-shadow: var(--shadow-xl);
  animation: slideIn 0.3s cubic-bezier(0.4, 0, 0.2, 1);
  overflow: hidden;
  display: flex;
  flex-direction: column;
}

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

.modal-header {
  display: flex;
  justify-content: space-between;
  align-items: center;
  padding: var(--spacing-lg);
  border-bottom: 1px solid var(--border-color);
  background: var(--bg-secondary);
}

.modal-header h2 {
  margin: 0;
  font-size: 1.5rem;
  font-weight: 600;
  letter-spacing: -0.02em;
  color: var(--text-primary);
}

.modal-body {
  padding: 2rem 3rem 2.5rem 3rem;
  overflow-y: auto;
  flex: 1;
  line-height: 1.6;
}

.close {
  background: var(--bg-secondary);
  border: none;
  border-radius: var(--radius-md);
  padding: 0.5rem 0.75rem;
  font-size: 1.5rem;
  font-weight: 400;
  cursor: pointer;
  transition: all var(--transition-fast);
  color: var(--text-secondary);
  line-height: 1;
}

.close:hover {
  background: var(--bg-tertiary);
  color: var(--text-primary);
}

/* Markdown Content Styles */
.markdown-content {
  line-height: 1.6;
  color: var(--text-primary);
}

.markdown-content h1,
.markdown-content h2,
.markdown-content h3 {
  margin-top: var(--spacing-lg);
  margin-bottom: var(--spacing-md);
  font-weight: 600;
  letter-spacing: -0.02em;
  color: var(--text-primary);
}

.markdown-content h1 {
  font-size: 2rem;
}
.markdown-content h2 {
  font-size: 1.5rem;
}
.markdown-content h3 {
  font-size: 1.25rem;
}

.markdown-content p {
  margin-bottom: var(--spacing-md);
  color: var(--text-secondary);
}

.markdown-content code {
  background: var(--bg-secondary);
  padding: 0.2rem 0.4rem;
  border-radius: 0.25rem;
  font-family: "SF Mono", "Monaco", "Courier New", monospace;
  font-size: 0.875em;
  color: var(--accent-primary);
}

.markdown-content pre {
  background: var(--bg-secondary);
  padding: var(--spacing-md);
  border-radius: var(--radius-lg);
  overflow-x: auto;
  margin-bottom: var(--spacing-md);
}

.markdown-content pre code {
  background: none;
  padding: 0;
  color: var(--text-primary);
}

.markdown-content ul,
.markdown-content ol {
  margin-left: var(--spacing-lg);
  margin-bottom: var(--spacing-md);
  color: var(--text-secondary);
}

.markdown-content li {
  margin-bottom: var(--spacing-xs);
}

.markdown-content a {
  color: var(--accent-primary);
  text-decoration: none;
  border-bottom: 1px solid transparent;
  transition: border-color var(--transition-fast);
}

.markdown-content a:hover {
  border-bottom-color: var(--accent-primary);
}

.loading {
  text-align: center;
  padding: var(--spacing-xl);
  color: var(--text-secondary);
  font-size: 1.125rem;
}

/* ============================================
   Responsive Design
   ============================================ */
@media (max-width: 768px) {
  .nav-links {
    display: none;
  }

  .hero-title {
    font-size: 2.5rem;
  }

  .hero-stats {
    flex-direction: column;
    gap: var(--spacing-md);
  }

  .hero-cta {
    flex-direction: column;
  }

  .subjects-grid,
  .features-grid,
  .emergency-grid {
    grid-template-columns: 1fr;
  }

  .modal-content {
    width: 95%;
    margin: 5% auto;
  }

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

/* ============================================
   Responsive Design
   ============================================ */
@media (max-width: 768px) {
  .navbar .container {
    padding: 0 1rem;
  }

  .nav-links {
    display: none;
    position: fixed;
    top: 70px;
    left: 0;
    right: 0;
    background: var(--card-bg);
    flex-direction: column;
    padding: 1rem;
    gap: 0.5rem;
    box-shadow: var(--shadow-lg);
    border-bottom: 1px solid var(--border-color);
    z-index: 999;
  }

  .nav-links.active {
    display: flex;
  }

  .nav-link {
    padding: 0.75rem 1rem;
    border-radius: var(--radius-md);
    background: var(--bg-secondary);
  }

  .nav-link::after {
    display: none;
  }

  .hamburger {
    display: flex;
  }

  .hero-title {
    font-size: 2.5rem;
  }

  .hero-stats {
    flex-direction: column;
    gap: 1.5rem;
  }

  .features-grid,
  .subjects-grid,
  .emergency-grid {
    grid-template-columns: 1fr;
  }

  .modal-content {
    width: 95%;
    max-height: 90vh;
    margin: 1rem;
  }

  .modal-body {
    padding: 1.5rem;
  }

  .search-container {
    margin: 1rem;
    max-width: calc(100% - 2rem);
  }

  .search-filters {
    padding: 0.75rem 1rem;
  }

  .filter-btn {
    font-size: 0.8125rem;
    padding: 0.4rem 0.875rem;
  }
}

@media (max-width: 480px) {
  .hero-title {
    font-size: 2rem;
  }

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

/* ============================================
   Utility Classes
   ============================================ */
.text-center {
  text-align: center;
}

.hidden {
  display: none;
}

/* ============================================
   Back to Top Button
   ============================================ */
.back-to-top {
  position: fixed;
  bottom: 2rem;
  right: 2rem;
  width: 3rem;
  height: 3rem;
  background: var(--accent-primary);
  color: white;
  border: none;
  border-radius: 50%;
  cursor: pointer;
  display: flex;
  align-items: center;
  justify-content: center;
  box-shadow: var(--shadow-lg);
  transition: all var(--transition-fast);
  opacity: 0;
  visibility: hidden;
  transform: translateY(20px);
  z-index: 999;
}

.back-to-top.visible {
  opacity: 1;
  visibility: visible;
  transform: translateY(0);
}

.back-to-top:hover {
  background: var(--accent-secondary);
  transform: translateY(-4px);
  box-shadow: var(--shadow-xl);
}

.back-to-top:active {
  transform: translateY(-2px);
}

/* ============================================
   Loading Skeletons
   ============================================ */
.skeleton {
  background: linear-gradient(
    90deg,
    var(--bg-secondary) 0%,
    var(--bg-tertiary) 50%,
    var(--bg-secondary) 100%
  );
  background-size: 200% 100%;
  animation: shimmer 1.5s infinite;
  border-radius: var(--radius-md);
}

@keyframes shimmer {
  0% {
    background-position: 200% 0;
  }
  100% {
    background-position: -200% 0;
  }
}

.skeleton-text {
  height: 1rem;
  margin-bottom: 0.5rem;
}

.skeleton-text:last-child {
  width: 60%;
}

.skeleton-heading {
  height: 2rem;
  width: 40%;
  margin-bottom: 1rem;
}

.skeleton-card {
  padding: 1.5rem;
  background: var(--card-bg);
  border-radius: var(--radius-lg);
  border: 1px solid var(--border-color);
}

.skeleton-paragraph {
  display: flex;
  flex-direction: column;
  gap: 0.5rem;
}

/* ============================================
   Keyboard Shortcuts Hint
   ============================================ */
.kbd {
  display: inline-block;
  padding: 0.25rem 0.5rem;
  background: var(--bg-secondary);
  border: 1px solid var(--border-color);
  border-radius: 0.25rem;
  font-family: monospace;
  font-size: 0.875rem;
  box-shadow: 0 1px 2px rgba(0, 0, 0, 0.1);
}

.search-hint {
  position: absolute;
  right: 1.5rem;
  top: 50%;
  transform: translateY(-50%);
  color: var(--text-secondary);
  font-size: 0.875rem;
  display: flex;
  align-items: center;
  gap: 0.5rem;
  pointer-events: none;
}