/* ============================================================
   YOLO-Master GitHub Pages — Material for MkDocs Indigo Theme
   ============================================================ */

/* ── CSS Variables ── */
:root {
  --color-primary: #3f51b5;
  --color-primary-dark: #303f9f;
  --color-primary-light: #e8eaf6;
  --color-primary-hover: #3949ab;
  --color-accent: #536dfe;

  --color-bg: #ffffff;
  --color-bg-alt: #fafafa;
  --color-bg-sidebar: #ffffff;
  --color-bg-toc: transparent;
  --color-bg-code: #f5f5f5;
  --color-bg-nav: #3f51b5;

  --color-text: #212121;
  --color-text-secondary: #616161;
  --color-text-muted: #9e9e9e;
  --color-text-inverse: #ffffff;
  --color-text-nav: rgba(255,255,255,0.7);
  --color-text-nav-active: #ffffff;

  --color-border: #e0e0e0;
  --color-border-light: #eeeeee;
  --color-border-nav: rgba(255,255,255,0.12);

  --font-sans: 'Roboto', -apple-system, BlinkMacSystemFont, 'Segoe UI', 'Helvetica Neue', Arial, sans-serif;
  --font-mono: 'Roboto Mono', 'SFMono-Regular', Consolas, 'Liberation Mono', Menlo, monospace;

  --radius-sm: 4px;
  --radius-md: 8px;
  --radius-lg: 12px;

  --shadow-sm: 0 1px 3px rgba(0,0,0,0.08);
  --shadow-md: 0 2px 8px rgba(0,0,0,0.1);
  --shadow-lg: 0 4px 16px rgba(0,0,0,0.12);

  --max-width: 1200px;
  --nav-height: 56px;
  --sidebar-width: 260px;
  --toc-width: 220px;

  --transition-fast: 150ms ease;
  --transition-base: 200ms ease;
}

/* ── Reset & Base ── */
*, *::before, *::after { box-sizing: border-box; margin: 0; padding: 0; }

html { scroll-behavior: smooth; scroll-padding-top: calc(var(--nav-height) + 16px); }

body {
  font-family: var(--font-sans);
  font-size: 16px;
  line-height: 1.65;
  color: var(--color-text);
  background: var(--color-bg);
  -webkit-font-smoothing: antialiased;
}

a { color: var(--color-primary); text-decoration: none; transition: color var(--transition-fast); }
a:hover { color: var(--color-primary-hover); text-decoration: underline; }

img { max-width: 100%; height: auto; }

/* ── Typography ── */
h1, h2, h3, h4, h5, h6 { font-weight: 500; line-height: 1.3; color: var(--color-text); margin-bottom: 0.6em; }

h1 { font-size: 2.5rem; font-weight: 300; letter-spacing: -0.01em; }
h2 { font-size: 1.75rem; font-weight: 400; }
h3 { font-size: 1.35rem; font-weight: 500; }
h4 { font-size: 1.15rem; font-weight: 500; }
h5 { font-size: 1rem; font-weight: 500; }
h6 { font-size: 0.9rem; font-weight: 500; }

p { margin-bottom: 1em; color: var(--color-text-secondary); }
p:last-child { margin-bottom: 0; }

.text-center { text-align: center; }
.text-muted { color: var(--color-text-muted); }
.text-gradient {
  background: linear-gradient(135deg, var(--color-primary) 0%, var(--color-accent) 100%);
  -webkit-background-clip: text; -webkit-text-fill-color: transparent; background-clip: text;
}

/* ── Layout ── */
.container { max-width: var(--max-width); margin: 0 auto; padding: 0 1.5rem; }

.section { padding: 3rem 0; }
.section-alt { background: var(--color-bg-alt); }

/* ── Top App Bar (Navigation) ── */
.app-bar {
  position: fixed; top: 0; left: 0; right: 0;
  height: var(--nav-height);
  background: var(--color-bg-nav);
  color: var(--color-text-inverse);
  z-index: 1000;
  box-shadow: 0 2px 4px rgba(0,0,0,0.1);
}

.app-bar-inner {
  max-width: var(--max-width);
  margin: 0 auto; padding: 0 1.25rem;
  height: 100%;
  display: flex; align-items: center; justify-content: space-between;
}

.app-bar-brand {
  display: flex; align-items: center; gap: 0.6rem;
  font-size: 1.15rem; font-weight: 500;
  color: var(--color-text-inverse);
  text-decoration: none !important;
}
.app-bar-brand:hover { color: var(--color-text-inverse); }

.app-bar-brand-icon {
  width: 28px; height: 28px;
  display: flex; align-items: center; justify-content: center;
  font-size: 1rem;
}

.app-bar-links {
  display: flex; align-items: center; gap: 0;
  flex: 1; margin-left: 2rem;
}

.app-bar-links a {
  display: flex; align-items: center; gap: 0.35rem;
  padding: 0 0.9rem;
  font-size: 0.85rem; font-weight: 500;
  color: var(--color-text-nav);
  text-decoration: none !important;
  transition: color var(--transition-fast);
  height: var(--nav-height); line-height: var(--nav-height);
}

.app-bar-links a:hover,
.app-bar-links a.active {
  color: var(--color-text-nav-active);
}

.app-bar-search {
  display: flex; align-items: center;
  background: rgba(255,255,255,0.12);
  border-radius: var(--radius-md);
  padding: 0.35rem 0.75rem;
  min-width: 200px;
  margin: 0 1.5rem;
  color: rgba(255,255,255,0.6);
  font-size: 0.85rem;
}
.app-bar-search i { margin-right: 0.4rem; font-size: 0.8rem; }
.app-bar-search { text-decoration: none !important; }
.app-bar-search:hover, .app-bar-search:focus { color: #fff; background: rgba(255,255,255,0.2); }

.app-bar-meta {
  display: flex; align-items: center; gap: 1rem;
  font-size: 0.8rem; color: rgba(255,255,255,0.8);
}
.app-bar-meta a { color: rgba(255,255,255,0.8); text-decoration: none !important; }
.app-bar-meta a:hover { color: #fff; }

.meta-badge { height: 18px; vertical-align: middle; margin-left: 0.3rem; }

.app-bar-toggle {
  display: none; background: none; border: none;
  color: var(--color-text-inverse); font-size: 1.25rem; cursor: pointer;
}

/* ── Hero / Intro Section ── */
.hero-intro {
  padding-top: calc(var(--nav-height) + 3rem);
  padding-bottom: 3rem;
  text-align: center;
  max-width: 720px; margin: 0 auto;
}

.hero-intro h1 {
  font-size: 2.75rem; font-weight: 300;
  line-height: 1.25;
  margin-bottom: 1.5rem;
}

.hero-intro .mascot {
  width: 120px; height: auto;
  margin: 1.5rem auto;
}

.hero-intro .org-logo {
  display: flex; align-items: center; justify-content: center;
  gap: 0.5rem; margin-top: 1.5rem;
  font-size: 1.1rem; color: var(--color-text-secondary);
}
.hero-intro .org-logo img { height: 28px; }

.hero-logo {
  width: 120px; height: auto;
  margin: 1.5rem auto;
  display: block;
  border-radius: 50%;
}

img.hero-logo {
  border-radius: 50%;
  box-shadow: 0 4px 12px rgba(63,81,181,0.15);
}

.org-logo-img {
  width: 28px; height: 28px;
  border-radius: 50%;
  object-fit: cover;
}

/* ── Content Area (3-column layout) ── */
.doc-layout {
  display: grid;
  grid-template-columns: var(--sidebar-width) 1fr var(--toc-width);
  gap: 2rem;
  max-width: var(--max-width); margin: 0 auto;
  padding: 0 1.5rem;
  padding-top: calc(var(--nav-height) + 1.5rem);
}

/* ── Left Sidebar ── */
.doc-sidebar {
  position: sticky;
  top: calc(var(--nav-height) + 1rem);
  height: calc(100vh - var(--nav-height) - 2rem);
  overflow-y: auto;
  padding-right: 0.5rem;
}

.doc-sidebar-nav { list-style: none; }

.doc-sidebar-nav li { margin-bottom: 0; }

.doc-sidebar-nav a {
  display: block; padding: 0.45rem 0.75rem;
  border-radius: var(--radius-sm);
  font-size: 0.85rem;
  color: var(--color-text-secondary);
  text-decoration: none !important;
  transition: all var(--transition-fast);
  border-left: 3px solid transparent;
}

.doc-sidebar-nav a:hover {
  color: var(--color-primary);
  background: var(--color-primary-light);
}

.doc-sidebar-nav a.active {
  color: var(--color-primary);
  background: var(--color-primary-light);
  border-left-color: var(--color-primary);
  font-weight: 500;
}

.doc-sidebar-nav .nav-section {
  font-size: 0.7rem; font-weight: 700;
  text-transform: uppercase; letter-spacing: 0.06em;
  color: var(--color-text-muted);
  padding: 1rem 0.75rem 0.4rem;
  pointer-events: none;
}

/* ── Right TOC ── */
.doc-toc {
  position: sticky;
  top: calc(var(--nav-height) + 1rem);
  height: calc(100vh - var(--nav-height) - 2rem);
  overflow-y: auto;
  padding-left: 0.5rem;
}

.doc-toc-title {
  font-size: 0.75rem; font-weight: 700;
  text-transform: uppercase; letter-spacing: 0.05em;
  color: var(--color-text-muted);
  margin-bottom: 0.75rem;
  padding-left: 0.5rem;
}

.doc-toc ul { list-style: none; }
.doc-toc li { margin-bottom: 0.1rem; }

.doc-toc a {
  display: block; padding: 0.3rem 0.5rem;
  font-size: 0.8rem;
  color: var(--color-text-muted);
  text-decoration: none !important;
  border-left: 2px solid transparent;
  transition: all var(--transition-fast);
}

.doc-toc a:hover { color: var(--color-primary); }
.doc-toc a.active {
  color: var(--color-primary);
  border-left-color: var(--color-primary);
  font-weight: 500;
}

.doc-toc a.level-2 { padding-left: 1rem; }
.doc-toc a.level-3 { padding-left: 1.5rem; font-size: 0.75rem; }

/* ── Main Content ── */
.doc-content {
  max-width: 740px;
  padding-bottom: 4rem;
  min-width: 0;
}

.doc-content h1 {
  font-size: 2.25rem; font-weight: 300;
  margin-bottom: 0.75rem;
  color: var(--color-text);
}

.doc-content h2 {
  font-size: 1.5rem; font-weight: 400;
  margin-top: 2.5rem; margin-bottom: 0.75rem;
  padding-bottom: 0.4rem;
  border-bottom: 1px solid var(--color-border-light);
}

.doc-content h3 {
  font-size: 1.15rem; font-weight: 500;
  margin-top: 1.75rem; margin-bottom: 0.6rem;
}

.doc-content p { margin-bottom: 1em; }

.doc-content ul, .doc-content ol {
  margin-left: 1.5rem; margin-bottom: 1em;
  color: var(--color-text-secondary);
}
.doc-content li { margin-bottom: 0.35rem; }

.doc-content blockquote {
  border-left: 4px solid var(--color-primary);
  background: var(--color-primary-light);
  padding: 0.75rem 1rem;
  margin: 1.25rem 0;
  border-radius: 0 var(--radius-sm) var(--radius-sm) 0;
  color: var(--color-text-secondary);
}
.doc-content blockquote p { margin-bottom: 0; }

.doc-content strong { color: var(--color-text); font-weight: 500; }

/* ── Tables ── */
.table-wrap {
  overflow-x: auto;
  margin: 1.25rem 0;
  border: 1px solid var(--color-border);
  border-radius: var(--radius-sm);
}

table {
  width: 100%; border-collapse: collapse;
  font-size: 0.85rem; background: white;
}

thead { background: var(--color-bg-alt); }

th {
  padding: 0.7rem 0.85rem;
  text-align: left; font-weight: 600;
  font-size: 0.75rem;
  text-transform: uppercase; letter-spacing: 0.03em;
  color: var(--color-text-secondary);
  border-bottom: 2px solid var(--color-border);
  white-space: nowrap;
}

td {
  padding: 0.6rem 0.85rem;
  border-bottom: 1px solid var(--color-border-light);
  color: var(--color-text-secondary);
}

tr:last-child td { border-bottom: none; }
tr:hover td { background: #fafafa; }

tr.highlight td {
  background: var(--color-primary-light);
  color: var(--color-primary-dark);
  font-weight: 500;
}

/* ── Code Blocks ── */
.code-block {
  background: var(--color-bg-code);
  color: #37474f;
  border-radius: var(--radius-sm);
  padding: 1rem;
  font-family: var(--font-mono);
  font-size: 0.82rem;
  line-height: 1.6;
  overflow-x: auto;
  position: relative;
  margin: 1.25rem 0;
  border-left: 4px solid var(--color-primary);
}

.code-block .code-header {
  display: flex; align-items: center; justify-content: space-between;
  margin-bottom: 0.6rem; padding-bottom: 0.4rem;
  border-bottom: 1px solid rgba(0,0,0,0.06);
}

.code-block .code-lang {
  font-size: 0.65rem; font-weight: 600;
  text-transform: uppercase; letter-spacing: 0.06em;
  color: var(--color-text-muted);
}

.code-block .code-copy {
  background: rgba(0,0,0,0.04); border: none;
  color: var(--color-text-muted);
  padding: 0.2rem 0.5rem;
  border-radius: var(--radius-sm);
  font-size: 0.7rem; cursor: pointer;
  transition: all var(--transition-fast);
}
.code-block .code-copy:hover { background: rgba(0,0,0,0.08); color: var(--color-text); }

.code-block pre { margin: 0; white-space: pre; word-wrap: normal; }
.code-block code { font-family: var(--font-mono); color: inherit; }

.code-inline {
  background: #f5f5f5; color: #e91e63;
  padding: 0.1rem 0.35rem;
  border-radius: 3px;
  font-family: var(--font-mono);
  font-size: 0.82em;
}

/* ── Info Boxes ── */
.info-box {
  border-radius: var(--radius-sm);
  padding: 1rem 1.25rem;
  margin: 1.25rem 0;
  display: flex; gap: 0.6rem; align-items: flex-start;
  font-size: 0.9rem;
}

.info-box.info {
  background: #e3f2fd;
  border-left: 4px solid #2196f3;
  color: #1565c0;
}
.info-box.success {
  background: #e8f5e9;
  border-left: 4px solid #4caf50;
  color: #2e7d32;
}
.info-box.warning {
  background: #fff8e1;
  border-left: 4px solid #ffc107;
  color: #f57f17;
}
.info-box.danger {
  background: #ffebee;
  border-left: 4px solid #f44336;
  color: #c62828;
}
.info-box .icon { font-size: 1rem; flex-shrink: 0; margin-top: 0.15rem; }
.info-box p { margin: 0; color: inherit; font-size: 0.9rem; }

/* ── Abstract Box ── */
.abstract-box {
  background: var(--color-bg-alt);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-md);
  padding: 1.5rem;
  margin: 1.5rem 0;
}

/* ── Feature Cards ── */
.features-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
  gap: 1.25rem;
}

.feature-card {
  background: white;
  border: 1px solid var(--color-border);
  border-radius: var(--radius-md);
  padding: 1.5rem;
  transition: all var(--transition-base);
}

.feature-card:hover {
  box-shadow: var(--shadow-md);
  border-color: var(--color-border);
}

.feature-icon {
  width: 40px; height: 40px;
  border-radius: var(--radius-sm);
  display: flex; align-items: center; justify-content: center;
  font-size: 1.1rem; margin-bottom: 0.75rem;
}

.feature-icon.blue   { background: #e3f2fd; color: #1976d2; }
.feature-icon.green  { background: #e8f5e9; color: #388e3c; }
.feature-icon.purple { background: #f3e5f5; color: #7b1fa2; }
.feature-icon.orange { background: #fff3e0; color: #f57c00; }
.feature-icon.pink   { background: #fce4ec; color: #c2185b; }
.feature-icon.cyan   { background: #e0f7fa; color: #00838f; }
.feature-icon.indigo { background: #e8eaf6; color: #303f9f; }

.feature-card h3 { font-size: 1rem; margin-bottom: 0.4rem; }
.feature-card p { font-size: 0.85rem; color: var(--color-text-secondary); margin-bottom: 0; }

/* ── Gallery ── */
.gallery-grid {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 1rem;
}

.gallery-item {
  border-radius: var(--radius-md);
  overflow: hidden;
  box-shadow: var(--shadow-sm);
  border: 1px solid var(--color-border);
}

.gallery-item img { width: 100%; height: 100%; object-fit: cover; display: block; }

/* ── Model Zoo Cards ── */
.model-card {
  background: white;
  border: 1px solid var(--color-border);
  border-radius: var(--radius-md);
  padding: 1.25rem;
  transition: all var(--transition-base);
}

.model-card:hover { box-shadow: var(--shadow-md); }

.model-card-header {
  display: flex; align-items: center; justify-content: space-between;
  margin-bottom: 0.75rem;
}

.model-card-title { font-size: 1rem; font-weight: 500; color: var(--color-text); }

.model-card-badge {
  padding: 0.15rem 0.5rem;
  border-radius: 9999px;
  font-size: 0.65rem; font-weight: 600;
  text-transform: uppercase;
}

.badge-new    { background: #c8e6c9; color: #2e7d32; }
.badge-hot    { background: #ffcdd2; color: #c62828; }
.badge-stable { background: #bbdefb; color: #1565c0; }

.model-card-stats {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 0.5rem; margin-bottom: 0.75rem;
}

.model-stat {
  background: var(--color-bg-alt);
  border-radius: var(--radius-sm);
  padding: 0.5rem; text-align: center;
}

.model-stat-value { font-size: 1rem; font-weight: 600; color: var(--color-text); }
.model-stat-label { font-size: 0.65rem; color: var(--color-text-muted); text-transform: uppercase; }

/* ── Buttons ── */
.btn {
  display: inline-flex; align-items: center; gap: 0.4rem;
  padding: 0.6rem 1.25rem;
  border-radius: var(--radius-sm);
  font-size: 0.85rem; font-weight: 500;
  text-decoration: none !important;
  transition: all var(--transition-fast);
  border: none; cursor: pointer;
}

.btn-primary {
  background: var(--color-primary);
  color: white;
  box-shadow: 0 2px 4px rgba(63,81,181,0.3);
}
.btn-primary:hover {
  background: var(--color-primary-hover);
  color: white; box-shadow: 0 3px 8px rgba(63,81,181,0.4);
}

.btn-secondary {
  background: white;
  color: var(--color-text);
  border: 1px solid var(--color-border);
  box-shadow: var(--shadow-sm);
}
.btn-secondary:hover { border-color: var(--color-text-muted); box-shadow: var(--shadow-md); color: var(--color-text); }

.btn-ghost { background: transparent; color: var(--color-text-secondary); }
.btn-ghost:hover { background: var(--color-bg-alt); color: var(--color-text); }

.btn-sm { padding: 0.4rem 0.8rem; font-size: 0.8rem; }

/* ── Demo Embed ── */
.demo-container {
  width: 100%;
  border-radius: var(--radius-md);
  overflow: hidden;
  border: 1px solid var(--color-border);
  box-shadow: var(--shadow-md);
  background: white;
}

.demo-header {
  display: flex; align-items: center; gap: 0.4rem;
  padding: 0.6rem 0.85rem;
  background: var(--color-bg-alt);
  border-bottom: 1px solid var(--color-border);
  font-size: 0.8rem; font-weight: 500;
}

.demo-frame { width: 100%; height: 650px; border: none; display: block; }

/* ── Section Header ── */
.section-header {
  text-align: center;
  max-width: 600px; margin: 0 auto 2rem;
}
.section-header h2 { margin-bottom: 0.5rem; font-weight: 300; font-size: 1.75rem; }
.section-header p { font-size: 0.95rem; color: var(--color-text-muted); }

/* ── Authors ── */
.authors-bar {
  display: flex; justify-content: center; flex-wrap: wrap;
  gap: 1.25rem; margin-top: 1.5rem;
}

.author-chip {
  display: flex; flex-direction: column; align-items: center; gap: 0.15rem;
}

.author-chip a { font-weight: 500; color: var(--color-primary); text-decoration: none !important; font-size: 0.9rem; }
.author-chip span { font-size: 0.75rem; color: var(--color-text-muted); }

/* ── Hero Badges ── */
.hero-badges {
  display: flex; justify-content: center; flex-wrap: wrap;
  gap: 0.4rem; margin: 1.25rem 0;
}

.hero-badges img { height: 20px; }

/* ── Hero Actions ── */
.hero-actions {
  display: flex; justify-content: center; gap: 0.6rem;
  flex-wrap: wrap; margin: 1.25rem 0;
}

/* ── Hero Badge (pill) ── */
.hero-badge {
  display: inline-flex; align-items: center; gap: 0.4rem;
  padding: 0.3rem 0.85rem;
  background: var(--color-primary-light);
  color: var(--color-primary-dark);
  border-radius: 9999px;
  font-size: 0.75rem; font-weight: 500;
  margin-bottom: 1rem;
}

.hero-badge .dot {
  width: 6px; height: 6px;
  background: var(--color-success);
  border-radius: 50%;
  animation: pulse 2s infinite;
}

@keyframes pulse {
  0%, 100% { opacity: 1; }
  50% { opacity: 0.4; }
}

/* ── Tabs ── */
.tabs {
  display: flex; gap: 0;
  border-bottom: 1px solid var(--color-border);
  margin-bottom: 1.25rem;
}

.tab {
  padding: 0.5rem 1rem;
  font-weight: 500;
  color: var(--color-text-muted);
  border-bottom: 2px solid transparent;
  margin-bottom: -1px;
  cursor: pointer;
  transition: all var(--transition-fast);
  background: none; border-top: none; border-left: none; border-right: none;
  font-size: 0.85rem;
}

.tab:hover { color: var(--color-text-secondary); }
.tab.active { color: var(--color-primary); border-bottom-color: var(--color-primary); }

/* ── Footer ── */
.footer {
  background: var(--color-bg-alt);
  color: var(--color-text-muted);
  padding: 2.5rem 0 1.5rem;
  border-top: 1px solid var(--color-border);
}

.footer-inner {
  max-width: var(--max-width);
  margin: 0 auto; padding: 0 1.5rem;
}

.footer-grid {
  display: grid;
  grid-template-columns: 2fr 1fr 1fr 1fr;
  gap: 2rem; margin-bottom: 1.5rem;
}

.footer-brand {
  display: flex; align-items: center; gap: 0.4rem;
  font-size: 1rem; font-weight: 500;
  color: var(--color-text);
  margin-bottom: 0.5rem;
}

.footer-desc {
  font-size: 0.8rem; line-height: 1.6;
  max-width: 280px; color: var(--color-text-muted);
}

.footer-heading {
  font-size: 0.7rem; font-weight: 700;
  text-transform: uppercase; letter-spacing: 0.06em;
  color: var(--color-text-secondary);
  margin-bottom: 0.75rem;
}

.footer-links { list-style: none; }
.footer-links li { margin-bottom: 0.4rem; }
.footer-links a {
  color: var(--color-text-muted); font-size: 0.8rem;
  text-decoration: none !important;
  transition: color var(--transition-fast);
}
.footer-links a:hover { color: var(--color-primary); }

.footer-bottom {
  border-top: 1px solid var(--color-border);
  padding-top: 1.25rem;
  display: flex; justify-content: space-between; align-items: center;
  flex-wrap: wrap; gap: 0.75rem;
  font-size: 0.75rem; color: var(--color-text-muted);
}

/* ── Admonitions (Material style) ── */
.admonition {
  border-radius: var(--radius-sm);
  padding: 0.75rem 1rem;
  margin: 1rem 0;
  font-size: 0.9rem;
  border-left: 4px solid;
}

.admonition.note {
  background: #e3f2fd;
  border-left-color: #2196f3;
  color: #0d47a1;
}
.admonition.tip {
  background: #e8f5e9;
  border-left-color: #4caf50;
  color: #1b5e20;
}
.admonition.warning {
  background: #fff8e1;
  border-left-color: #ff9800;
  color: #e65100;
}
.admonition.danger {
  background: #ffebee;
  border-left-color: #f44336;
  color: #b71c1c;
}

.admonition-title {
  font-weight: 600;
  margin-bottom: 0.3rem;
  display: flex; align-items: center; gap: 0.4rem;
}

/* ── Utilities ── */
.mt-1 { margin-top: 0.5rem; }
.mt-2 { margin-top: 1rem; }
.mt-3 { margin-top: 1.5rem; }
.mb-1 { margin-bottom: 0.5rem; }
.mb-2 { margin-bottom: 1rem; }
.mb-3 { margin-bottom: 1.5rem; }

.flex { display: flex; }
.flex-wrap { flex-wrap: wrap; }
.gap-1 { gap: 0.5rem; }
.gap-2 { gap: 1rem; }
.items-center { align-items: center; }
.justify-center { justify-content: center; }

.grid-2 { display: grid; grid-template-columns: repeat(2, 1fr); gap: 1.25rem; }
.grid-3 { display: grid; grid-template-columns: repeat(3, 1fr); gap: 1.25rem; }
.grid-4 { display: grid; grid-template-columns: repeat(4, 1fr); gap: 1.25rem; }

/* ── Responsive ── */
@media (max-width: 1024px) {
  .doc-layout { grid-template-columns: var(--sidebar-width) 1fr; }
  .doc-toc { display: none; }
  .footer-grid { grid-template-columns: 1fr 1fr; }
}

@media (max-width: 768px) {
  .app-bar-links, .app-bar-search, .app-bar-meta { display: none; }
  .app-bar-toggle { display: block; }

  .doc-layout {
    grid-template-columns: 1fr;
    padding-top: calc(var(--nav-height) + 1rem);
  }
  .doc-sidebar { display: none; }
  .doc-content { max-width: 100%; }

  .hero-intro h1 { font-size: 2rem; }

  .features-grid { grid-template-columns: 1fr; }
  .gallery-grid { grid-template-columns: 1fr; }
  .grid-2, .grid-3, .grid-4 { grid-template-columns: 1fr; }
  .footer-grid { grid-template-columns: 1fr; }

  .demo-frame { height: 500px; }
}