:root {
  --font-base: 'Inter', 'Sarabun', system-ui, -apple-system, BlinkMacSystemFont, 'Segoe UI', sans-serif;
  --font-thai: 'Sarabun', 'Inter', sans-serif;
  --color-bg: #f8fafc;
  --color-surface: #ffffff;
  --color-text: #1e293b;
  --color-muted: #64748b;
  --color-link: #3b82f6;
  --color-border: rgba(30, 41, 59, 0.08);
  --color-highlight: #f1f5f9;
  --color-accent: #3b82f6;
  --color-success: #10b981;
  --color-warning: #f59e0b;
  --sidebar-width: 300px;
  --transition: 0.3s cubic-bezier(0.22, 1, 0.36, 1);
  --bg-secondary: #f1f5f9;
}
[data-theme="dark"] {
  --color-bg: #0b1120;
  --color-surface: #121a2f;
  --color-text: #e2e8f0;
  --color-muted: #94a3b8;
  --color-link: #60a5fa;
  --color-border: rgba(148, 163, 184, 0.16);
  --color-highlight: rgba(148, 163, 184, 0.1);
  --color-accent: #38bdf8;
  --bg-secondary: #1e293b;
}
* {
  box-sizing: border-box;
}
html, body {
  margin: 0;
  padding: 0;
  font-family: var(--font-base);
  background-color: var(--color-bg);
  color: var(--color-text);
  transition: background-color var(--transition), color var(--transition);
}
body {
  min-height: 100vh;
}
h1, h2, h3, h4, h5, h6 {
  font-weight: 700;
  color: var(--color-text);
  letter-spacing: -0.02em;
}
p {
  line-height: 1.7;
  color: var(--color-muted);
}
a {
  color: var(--color-link);
  text-decoration: none;
  transition: color var(--transition), background-color var(--transition);
}
a:hover,
a:focus {
  color: var(--color-accent);
}
.layout {
  display: grid;
  grid-template-columns: var(--sidebar-width) 1fr;
  min-height: 100vh;
}
.sidebar {
  background-color: var(--color-surface);
  border-right: 1px solid var(--color-border);
  padding: 24px;
  position: sticky;
  top: 0;
  height: 100%;
  overflow-y: auto;
  transition: transform var(--transition);
}
.sidebar-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  margin-bottom: 24px;
}
.sidebar .brand {
  display: flex;
  align-items: center;
  gap: 12px;
  font-weight: 700;
  font-size: 1.1rem;
  color: var(--color-text);
}
.sidebar .brand i {
  font-size: 1.4rem;
  color: var(--color-accent);
}
.sidebar-toggle {
  border: none;
  background: transparent;
  color: var(--color-muted);
  font-size: 1.5rem;
  display: none;
}
.sidebar-search form {
  display: flex;
  gap: 12px;
  background-color: var(--color-highlight);
  padding: 8px 12px;
  border-radius: 12px;
  margin-bottom: 32px;
}
.sidebar-search input {
  flex: 1;
  width: 100%;
  border: none;
  background: transparent;
  color: var(--color-text);
  font-size: 0.95rem;
}
.sidebar-search input:focus {
  outline: none;
}
.sidebar-search button {
  border: none;
  background: transparent;
  color: var(--color-muted);
  font-size: 1.2rem;
  cursor: pointer;
}
.sidebar nav {
  padding-bottom: 60px;
}
.toc {
  list-style: none;
  padding: 0;
  margin: 0;
  display: flex;
  flex-direction: column;
  gap: 8px;
}
.toc-item {
  transition: background-color var(--transition), border-color var(--transition);
}
nav > ul.toc > .toc-item {
  border: 1px solid transparent;
  border-radius: 12px;
}
.toc-item.active {
  border-color: var(--color-border);
  background-color: rgba(0, 0, 0, 0.05);
}
.toc-item .toc-item {
  padding-left: 8px;
}
.toc-item > a,
.toc-item summary {
  display: flex;
  align-items: center;
  gap: 12px;
  padding: 10px 12px;
  color: var(--color-muted);
  cursor: pointer;
}
.toc-item > a i {
  color: var(--color-accent);
}
.toc-item summary::-webkit-details-marker {
  display: none;
}
.toc-item details summary {
  justify-content: space-between;
}
.toc-item details .summary-link {
  padding: 4px;
  display: inline-flex;
  border-radius: 8px;
  background: rgba(99, 102, 241, 0.1);
}
.content {
  min-height: 100vh;
  display: flex;
  flex-direction: column;
}
.topbar {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 24px 32px;
  background-color: rgba(255, 255, 255, 0.8);
  backdrop-filter: blur(12px);
  border-bottom: 1px solid var(--color-border);
  position: sticky;
  top: 0;
  z-index: 10;
}
[data-theme="dark"] .topbar {
  background-color: rgba(18, 26, 47, 0.9);
}
.topbar-left {
  display: flex;
  align-items: center;
  gap: 16px;
}
.topbar-left h1 {
  font-size: 1.2rem;
  margin: 0;
}
.topbar-actions {
  display: flex;
  align-items: center;
  gap: 16px;
}
.language-switcher {
  display: flex;
  gap: 8px;
}
.language-switcher .lang {
  padding: 6px 12px;
  border-radius: 999px;
  border: 1px solid var(--color-border);
  display: flex;
  align-items: center;
  gap: 4px;
  font-size: 0.85rem;
  letter-spacing: 0.04em;
  color: var(--color-muted);
}
.language-switcher .lang.active {
  background-color: var(--color-accent);
  color: #fff;
  border-color: transparent;
}
.theme-toggle {
  border: none;
  background: var(--color-highlight);
  border-radius: 999px;
  color: var(--color-muted);
  font-size: 1.1rem;
  padding: 8px 10px;
  cursor: pointer;
}
.doc-wrapper {
  flex: 1;
  padding: 32px;
  line-height: 2;
}
.doc-header {
  margin-bottom: 32px;
  display: flex;
  flex-direction: column;
  gap: 16px;
}
.breadcrumbs {
  display: flex;
  align-items: center;
  gap: 8px;
  font-size: 0.85rem;
  color: var(--color-muted);
}
.breadcrumbs i {
  color: var(--color-accent);
}
.doc-tagline {
  text-transform: uppercase;
  letter-spacing: 0.2em;
  font-size: 0.75rem;
  margin: 0;
  color: var(--color-accent);
}
.doc-header h2 {
  font-size: clamp(2rem, 5vw, 2.6rem);
  margin: 0;
}
.doc-meta {
  display: flex;
  gap: 16px;
  font-size: 0.85rem;
  color: var(--color-muted);
}
.doc-meta span {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  background-color: var(--color-highlight);
  padding: 6px 12px;
  border-radius: 999px;
}
.doc-content {
  background-color: var(--color-surface);
  border-radius: 16px;
  padding: 48px;
  border: 1px solid var(--color-border);
  box-shadow: 0 1px 3px rgba(0, 0, 0, 0.05);
}
/* E-Learning Enhancements */
.doc-content h1 {
  font-size: 2.5rem;
  margin-bottom: 1.5rem;
  color: var(--color-text);
  border-bottom: 3px solid var(--color-accent);
  padding-bottom: 0.5rem;
}
.doc-content h2 {
  font-size: 1.875rem;
  margin-top: 3rem;
  margin-bottom: 1rem;
  color: var(--color-text);
  display: flex;
  align-items: center;
  gap: 0.5rem;
}
.doc-content h2::before {
  content: "📚";
  font-size: 1.5rem;
}
.doc-content h3 {
  font-size: 1.5rem;
  margin-top: 2rem;
  margin-bottom: 0.75rem;
  color: var(--color-text);
}
.doc-content p {
  margin-bottom: 1.25rem;
  line-height: 1.8;
}
.doc-content ul, .doc-content ol {
  margin: 1.5rem 0;
  padding-left: 2rem;
}
.doc-content li {
  margin-bottom: 0.75rem;
  line-height: 1.7;
}
.doc-content strong {
  color: var(--color-text);
  font-weight: 600;
}
.doc-content pre {
  background-color: #0f172a;
  color: #e2e8f0;
  padding: 16px;
  border-radius: 16px;
  overflow-x: auto;
}
.doc-content code {
  font-family: 'Fira Code', 'JetBrains Mono', monospace;
  font-size: 0.9rem;
}
.doc-content pre code {
  display: block;
  padding: 0;
}
.doc-content table {
  width: 100%;
  border-collapse: collapse;
  margin: 24px 0;
}
.doc-content th,
.doc-content td {
  border: 1px solid var(--color-border);
  padding: 12px;
  text-align: left;
}
.doc-content blockquote {
  border-left: 4px solid var(--color-accent);
  background-color: var(--color-highlight);
  margin: 16px 0;
  padding: 12px 16px;
  color: var(--color-muted);
}
.doc-footer {
  margin-top: 48px;
}
.doc-footer-card {
  display: flex;
  align-items: center;
  justify-content: space-between;
  background: linear-gradient(135deg, rgba(99, 102, 241, 0.12), rgba(14, 165, 233, 0.12));
  border: 1px solid rgba(99, 102, 241, 0.24);
  padding: 24px 32px;
  border-radius: 24px;
  flex-wrap: wrap;
  gap: 16px;
}
.doc-footer-card .btn {
  background-color: var(--color-accent);
  color: #fff;
  padding: 10px 18px;
  border-radius: 12px;
  display: inline-flex;
  align-items: center;
  gap: 8px;
  font-weight: 600;
}
.doc-footer-card .btn:hover {
  opacity: 0.9;
}
.search-header {
  text-align: center;
  padding: 24px 0;
}
.search-form {
  display: flex;
  justify-content: center;
  gap: 12px;
  margin: 24px auto;
  max-width: 520px;
}
.search-form input {
  flex: 1;
  padding: 12px 16px;
  border-radius: 999px;
  border: 1px solid var(--color-border);
  background-color: var(--color-surface);
  color: var(--color-text);
}
.search-form button {
  border: none;
  background-color: var(--color-accent);
  color: #fff;
  border-radius: 999px;
  padding: 0 16px;
  cursor: pointer;
}
.search-hint {
  color: var(--color-muted);
  font-size: 0.9rem;
}
.search-results ul {
  list-style: none;
  padding: 0;
  display: grid;
  gap: 16px;
}
.search-results li a {
  display: block;
  padding: 20px;
  border-radius: 16px;
  border: 1px solid var(--color-border);
  background-color: var(--color-surface);
  transition: transform var(--transition), box-shadow var(--transition);
}
.search-results li a:hover {
  transform: translateY(-4px);
  box-shadow: 0 24px 32px -24px rgba(15, 23, 42, 0.45);
}
.search-results h3 {
  margin: 0 0 8px;
}
.badge {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  padding: 4px 12px;
  border-radius: 999px;
  background-color: var(--color-highlight);
  color: var(--color-muted);
  font-size: 0.75rem;
  margin-top: 12px;
}
.search-empty {
  display: grid;
  place-items: center;
  padding: 48px 24px;
  border: 1px dashed var(--color-border);
  border-radius: 24px;
  background-color: var(--color-surface);
  gap: 12px;
}
.search-empty i {
  font-size: 2.4rem;
  color: var(--color-accent);
}
.error {
  display: grid;
  place-items: center;
  padding: 120px 0;
}
.error-card {
  text-align: center;
  background-color: var(--color-surface);
  border-radius: 24px;
  padding: 48px 32px;
  border: 1px solid var(--color-border);
  box-shadow: 0 24px 48px -32px rgba(15, 23, 42, 0.35);
}
.error-card i {
  font-size: 2.6rem;
  color: var(--color-accent);
}
.btn {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  border-radius: 12px;
  padding: 10px 18px;
  background-color: var(--color-accent);
  color: #fff;
  font-weight: 600;
}
.sr-only {
  position: absolute;
  width: 1px;
  height: 1px;
  padding: 0;
  margin: -1px;
  overflow: hidden;
  clip: rect(0, 0, 0, 0);
  border: 0;
}
@media (max-width: 1080px) {
  :root {
    --sidebar-width: 280px;
  }
}
@media (max-width: 920px) {
  .layout {
    grid-template-columns: 1fr;
  }
  .sidebar {
    position: fixed;
    left: 0;
    top: 0;
    bottom: 0;
    transform: translateX(-100%);
    z-index: 20;
  }
  .sidebar[data-open="true"] {
    transform: translateX(0);
  }
  .sidebar-toggle {
    display: inline-flex;
  }
  .content {
    margin-left: 0;
  }
  .topbar-search input {
    min-width: 120px;
  }
  .doc-wrapper {
    padding: 24px 20px;
  }
}
@media (max-width: 600px) {
  .topbar {
    flex-direction: column;
    align-items: stretch;
    gap: 16px;
  }
  .topbar-actions {
    justify-content: flex-end;
  }
}
/* AI
 Assistant Link */
.sidebar-ai {
  padding: 0.75rem 1rem;
  border-top: 1px solid var(--color-border);
}
.ai-link {
  display: flex;
  align-items: center;
  gap: 0.75rem;
  padding: 0.75rem 1rem;
  background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
  color: white !important;
  border-radius: 8px;
  font-weight: 600;
  transition: transform 0.2s, box-shadow 0.2s;
  text-decoration: none;
}
.ai-link:hover {
  transform: translateY(-2px);
  box-shadow: 0 4px 12px rgba(102, 126, 234, 0.4);
}
.ai-link i {
  font-size: 1.2rem;
}
/* Navig
ation Toggle Icon */
.toc details summary {
  display: flex;
  align-items: center;
  gap: 0.5rem;
  cursor: pointer;
  user-select: none;
}
.toc details summary .toggle-icon {
  margin-left: auto;
  transition: transform 0.2s ease;
  font-size: 0.875rem;
  opacity: 0.6;
}
.toc details[open] summary .toggle-icon {
  transform: rotate(90deg);
}
.toc details summary::-webkit-details-marker {
  display: none;
}
.toc details summary::marker {
  display: none;
}
/* E-Le
arning Specific Styles */
.lesson-card {
  background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
  color: white;
  padding: 2rem;
  border-radius: 16px;
  margin-bottom: 2rem;
  box-shadow: 0 10px 30px rgba(102, 126, 234, 0.3);
}
.lesson-card h1 {
  margin: 0 0 0.5rem 0;
  font-size: 2rem;
  border: none !important;
  padding: 0 !important;
}
.lesson-card p {
  margin: 0;
  opacity: 0.95;
  font-size: 1.1rem;
}
.progress-indicator {
  display: flex;
  align-items: center;
  gap: 1rem;
  padding: 1rem;
  background-color: var(--color-highlight);
  border-radius: 12px;
  margin-bottom: 2rem;
}
.progress-indicator i {
  font-size: 1.5rem;
  color: var(--color-accent);
}
.code-example {
  position: relative;
  margin: 1.5rem 0;
}
.code-example::before {
  content: "💻 ตัวอย่างโค้ด";
  display: block;
  padding: 0.5rem 1rem;
  background-color: #1e293b;
  color: #94a3b8;
  font-size: 0.875rem;
  font-weight: 600;
  border-radius: 8px 8px 0 0;
  margin-bottom: -0.5rem;
}
.doc-content table {
  background-color: var(--color-surface);
  border-radius: 8px;
  overflow: hidden;
  box-shadow: 0 1px 3px rgba(0, 0, 0, 0.05);
}
.doc-content th {
  background-color: var(--color-accent);
  color: white;
  font-weight: 600;
  text-align: left;
}
.doc-content tr:nth-child(even) {
  background-color: var(--color-highlight);
}
.doc-content blockquote {
  border-left: 4px solid var(--color-warning);
  background-color: #fef3c7;
  margin: 1.5rem 0;
  padding: 1rem 1.5rem;
  border-radius: 8px;
}
[data-theme="dark"] .doc-content blockquote {
  background-color: rgba(245, 158, 11, 0.1);
  color: var(--color-text);
}
.exercise-box {
  background: linear-gradient(135deg, #10b981 0%, #059669 100%);
  color: white;
  padding: 1.5rem;
  border-radius: 12px;
  margin: 2rem 0;
}
.exercise-box h3, .exercise-box h4 {
  margin-top: 0;
  color: white;
}
.lesson-nav {
  display: flex;
  justify-content: space-between;
  gap: 1rem;
  margin-top: 3rem;
  padding-top: 2rem;
  border-top: 2px solid var(--color-border);
}
.lesson-nav-btn {
  display: flex;
  align-items: center;
  gap: 0.5rem;
  padding: 0.75rem 1.5rem;
  background-color: var(--color-accent);
  color: white;
  border-radius: 8px;
  font-weight: 600;
  transition: transform 0.2s, box-shadow 0.2s;
}
.lesson-nav-btn:hover {
  transform: translateY(-2px);
  box-shadow: 0 4px 12px rgba(59, 130, 246, 0.4);
}
.lesson-nav-btn.prev {
  background-color: var(--color-muted);
}
.home-hero {
  text-align: center;
  padding: 3rem 2rem;
  background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
  color: white;
  border-radius: 16px;
  margin-bottom: 3rem;
}
.home-hero h1 {
  font-size: 2.5rem;
  margin-bottom: 1rem;
  border: none !important;
  padding: 0 !important;
}
.home-hero p {
  font-size: 1.25rem;
  opacity: 0.95;
  max-width: 600px;
  margin: 0 auto;
}
.lesson-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
  gap: 1.5rem;
  margin: 2rem 0;
}
.lesson-item {
  background-color: var(--color-surface);
  border: 1px solid var(--color-border);
  border-radius: 12px;
  padding: 1.5rem;
  transition: transform 0.2s, box-shadow 0.2s;
}
.lesson-item:hover {
  transform: translateY(-4px);
  box-shadow: 0 8px 24px rgba(0, 0, 0, 0.1);
}
.lesson-item h3 {
  margin-top: 0;
  color: var(--color-accent);
  display: flex;
  align-items: center;
  gap: 0.5rem;
}
.lesson-number {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 32px;
  height: 32px;
  background-color: var(--color-accent);
  color: white;
  border-radius: 50%;
  font-weight: 700;
  font-size: 0.875rem;
}
@media (max-width: 768px) {
  .doc-content {
    padding: 24px;
  }
  .home-hero h1 {
    font-size: 1.875rem;
  }
  .lesson-grid {
    grid-template-columns: 1fr;
  }
}
/*
 Social Sharing Styles */
.social-sharing {
  margin-top: 3rem;
  padding-top: 2rem;
  border-top: 2px solid var(--color-border);
}
.social-sharing-title {
  font-size: 1rem;
  font-weight: 600;
  color: var(--color-text);
  margin-bottom: 1rem;
  display: flex;
  align-items: center;
  gap: 0.5rem;
}
.social-sharing-title i {
  font-size: 1.2rem;
  color: var(--color-accent);
}
.social-buttons {
  display: flex;
  gap: 0.75rem;
  flex-wrap: wrap;
}
.social-btn {
  display: inline-flex;
  align-items: center;
  gap: 0.5rem;
  padding: 0.625rem 1.25rem;
  border-radius: 8px;
  font-size: 0.9rem;
  font-weight: 500;
  text-decoration: none;
  transition: all 0.2s ease;
  border: 2px solid transparent;
}
.social-btn:hover {
  transform: translateY(-2px);
  box-shadow: 0 4px 12px rgba(0, 0, 0, 0.15);
}
.social-btn i,
.social-btn svg {
  font-size: 1.2rem;
}
/* Facebook */
.social-btn.facebook {
  background: #1877f2;
  color: white;
}
.social-btn.facebook:hover {
  background: #0d65d9;
}
/* X (Twitter) */
.social-btn.twitter {
  background: #000000;
  color: white;
}
.social-btn.twitter:hover {
  background: #1a1a1a;
}
/* LINE */
.social-btn.line {
  background: #00b900;
  color: white;
}
.social-btn.line:hover {
  background: #009900;
}
/* Copy Link */
.social-btn.copy {
  background: #6c757d;
  color: white;
}
.social-btn.copy:hover {
  background: #5a6268;
}
/* Dark mode adjustments */
[data-theme="dark"] .social-sharing {
  border-top-color: var(--color-border);
}
[data-theme="dark"] .social-sharing-title {
  color: var(--color-text);
}
/* Mobile responsive */
@media (max-width: 768px) {
  .social-buttons {
    flex-direction: column;
  }
  .social-btn {
    width: 100%;
    justify-content: center;
  }
}
/* Compact mode for smaller screens */
@media (max-width: 480px) {
  .social-btn span {
    display: none;
  }
  .social-btn {
    width: auto;
    padding: 0.625rem;
    justify-content: center;
  }
  .social-buttons {
    flex-direction: row;
    justify-content: center;
  }
}