/* ============================================================
   oBeaver docs — CSS3 stylesheet
   Brand: oBeaver — Build local. Dam the cloud.
   ============================================================ */

/* ---------- Google Fonts ---------- */
@import url('https://fonts.googleapis.com/css2?family=Fraunces:ital,opsz,wght@0,9..144,300;0,9..144,400;0,9..144,700;0,9..144,800;1,9..144,300;1,9..144,400&family=DM+Sans:wght@400;500;600;700&family=Space+Mono:wght@400;700&display=swap');

/* ---------- CSS Custom Properties (Light / Dark) ---------- */
:root {
  /* oBeaver brand palette */
  --ob-bark:    #1A0F05;
  --ob-brown:   #6B3D1A;
  --ob-amber:   #E8A828;
  --ob-birch:   #FDF5E6;
  --ob-river:   #2DD4A0;
  --ob-belly:   #C8A474;
  --ob-outline: #2A1205;
  --ob-tail:    #4A2810;

  --bg: #ffffff;
  --bg-secondary: var(--ob-birch);
  --bg-code: #faf6ee;
  --bg-sidebar: #ffffff;
  --bg-hover: #f5efe4;
  --bg-hero: var(--ob-bark);
  --text: #1A0F05;
  --text-secondary: #4a3b2a;
  --text-muted: #8b7a66;
  --border: #e5ddd0;
  --accent: var(--ob-amber);
  --accent-hover: #B07A20;
  --accent-light: rgba(232, 168, 40, 0.10);
  --code-text: var(--ob-amber);
  --link: var(--ob-amber);
  --link-hover: #B07A20;
  --shadow: 0 1px 3px rgba(26,15,5,0.06);
  --shadow-lg: 0 4px 20px rgba(26,15,5,0.10);
  --radius: 8px;
  --sidebar-width: 280px;
  --header-height: 60px;
  --font-sans: 'DM Sans', -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, sans-serif;
  --font-heading: 'Fraunces', Georgia, serif;
  --font-mono: 'Space Mono', "SF Mono", "Fira Code", Menlo, Consolas, monospace;
  --transition: 0.2s ease;
}

[data-theme="dark"] {
  --bg: #0f0a05;
  --bg-secondary: #1a1208;
  --bg-code: #1e1610;
  --bg-sidebar: #0f0a05;
  --bg-hover: #241a10;
  --bg-hero: var(--ob-bark);
  --text: #f0e8dc;
  --text-secondary: #c4b8a4;
  --text-muted: #8b7a66;
  --border: #3a2e20;
  --accent: var(--ob-amber);
  --accent-hover: #f0bc4c;
  --accent-light: rgba(232, 168, 40, 0.12);
  --code-text: var(--ob-amber);
  --link: var(--ob-amber);
  --link-hover: #f0bc4c;
  --shadow: 0 1px 3px rgba(0,0,0,0.3);
  --shadow-lg: 0 4px 20px rgba(0,0,0,0.4);
}

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

html {
  scroll-behavior: smooth;
  scroll-padding-top: calc(var(--header-height) + 20px);
}

body {
  font-family: var(--font-sans);
  font-size: 16px;
  line-height: 1.7;
  color: var(--text);
  background: var(--bg);
  transition: background var(--transition), color var(--transition);
  -webkit-font-smoothing: antialiased;
}

a {
  color: var(--link);
  text-decoration: none;
  transition: color var(--transition);
}
a:hover {
  color: var(--link-hover);
}

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

/* ---------- Header / Navbar ---------- */
.site-header {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  height: var(--header-height);
  background: var(--bg);
  border-bottom: 1px solid var(--border);
  z-index: 1000;
  display: flex;
  align-items: center;
  padding: 0 24px;
  -webkit-backdrop-filter: blur(10px);
  backdrop-filter: blur(10px);
  transition: background var(--transition), border-color var(--transition);
}

.header-inner {
  display: flex;
  align-items: center;
  justify-content: flex-start;
  width: 100%;
  max-width: 1440px;
  margin: 0 auto;
  gap: 20px;
}

.header-left {
  display: flex;
  align-items: center;
  gap: 16px;
  flex: 0 0 auto;
  min-width: 0;
}

.header-badge {
  display: none !important;
  align-items: center;
  padding: 6px 12px;
  border: 1px solid rgba(217, 119, 6, 0.25);
  border-radius: 999px;
  background: rgba(245, 158, 11, 0.12);
  color: #b45309;
  font-size: 0.76rem;
  font-weight: 800;
  letter-spacing: 0.06em;
  text-transform: uppercase;
  white-space: nowrap;
}

.logo {
  display: flex;
  align-items: center;
  gap: 10px;
  font-family: var(--font-heading);
  font-size: 1.25rem;
  font-weight: 800;
  color: var(--text);
  text-decoration: none;
  letter-spacing: -1px;
}
.logo:hover { color: var(--ob-amber); }

.logo img,
.logo svg {
  height: 32px;
  width: auto;
  image-rendering: -webkit-optimize-contrast;
  image-rendering: pixelated;
}

.logo-text {
  font-family: var(--font-heading);
  letter-spacing: -2px;
}
.logo-text .logo-o {
  font-style: italic;
  font-weight: 300;
  color: var(--ob-amber);
}
.logo-text .logo-beaver {
  font-weight: 800;
}

.header-right {
  display: flex;
  align-items: center;
  gap: 12px;
  margin-left: auto;
}

/* Search */
.search-box {
  position: relative;
  width: 240px;
}

.search-box input {
  width: 100%;
  padding: 8px 12px 8px 36px;
  border: 1px solid var(--border);
  border-radius: 6px;
  background: var(--bg-secondary);
  color: var(--text);
  font-size: 0.875rem;
  outline: none;
  transition: border-color var(--transition), box-shadow var(--transition);
}

.search-box input:focus {
  border-color: var(--accent);
  box-shadow: 0 0 0 3px var(--accent-light);
}

.search-box .search-icon {
  position: absolute;
  left: 10px;
  top: 50%;
  transform: translateY(-50%);
  color: var(--text-muted);
  pointer-events: none;
}

.search-results {
  position: absolute;
  top: 100%;
  left: 0;
  right: 0;
  background: var(--bg);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  box-shadow: var(--shadow-lg);
  max-height: 400px;
  overflow-y: auto;
  display: none;
  z-index: 100;
  margin-top: 4px;
}

.search-results.active { display: block; }

.search-result-item {
  display: block;
  padding: 10px 14px;
  border-bottom: 1px solid var(--border);
  color: var(--text);
  font-size: 0.875rem;
  transition: background var(--transition);
}
.search-result-item:last-child { border-bottom: none; }
.search-result-item:hover { background: var(--bg-hover); }
.search-result-item .result-title { font-weight: 600; }
.search-result-item .result-section {
  font-size: 0.75rem;
  color: var(--text-muted);
}

/* Theme toggle */
.theme-toggle {
  background: none;
  border: 1px solid var(--border);
  border-radius: 6px;
  padding: 6px 10px;
  cursor: pointer;
  color: var(--text);
  font-size: 1.1rem;
  display: flex;
  align-items: center;
  transition: background var(--transition), border-color var(--transition);
}
.theme-toggle:hover { background: var(--bg-hover); }

/* GitHub link */
.github-link {
  display: flex;
  align-items: center;
  color: var(--text);
  padding: 6px;
  border-radius: 6px;
  transition: background var(--transition);
}
.github-link:hover { background: var(--bg-hover); }
.github-link svg { width: 22px; height: 22px; fill: currentColor; }

/* Mobile menu button */
.menu-toggle {
  display: none;
  background: none;
  border: none;
  color: var(--text);
  font-size: 1.4rem;
  cursor: pointer;
  padding: 4px 8px;
}

/* ---------- Layout ---------- */
.docs-layout {
  display: flex;
  margin-top: var(--header-height);
  min-height: calc(100vh - var(--header-height));
}

.docs-layout-preview {
  position: relative;
  overflow: hidden;
}

.docs-layout-preview::after {
  content: "Tech Preview\A(CPU Only)";
  position: absolute;
  top: 28px;
  right: -74px;
  z-index: 950;
  padding: 10px 88px;
  background: linear-gradient(135deg, #d97706, #f59e0b);
  color: #fff7ed;
  font-size: 0.74rem;
  font-weight: 800;
  letter-spacing: 0.12em;
  line-height: 1.45;
  text-align: center;
  text-transform: uppercase;
  white-space: pre;
  box-shadow: 0 12px 24px rgba(0, 0, 0, 0.18);
  transform: rotate(35deg);
  transform-origin: center;
  pointer-events: none;
}

[data-lang="zh"] .docs-layout-preview::after {
  content: "技术预览版\A(仅提供 CPU 测试)";
  letter-spacing: 0.08em;
}

/* ---------- Sidebar ---------- */
.sidebar {
  position: fixed;
  top: var(--header-height);
  left: 0;
  bottom: 0;
  width: var(--sidebar-width);
  background: var(--bg-sidebar);
  border-right: 1px solid var(--border);
  overflow-y: auto;
  padding: 20px 0;
  transition: transform 0.3s ease, background var(--transition), border-color var(--transition);
  z-index: 900;
}

.sidebar-nav { padding: 0 16px; }

.sidebar-section {
  margin-bottom: 8px;
}

.sidebar-section-title {
  font-size: 0.7rem;
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: 0.08em;
  color: var(--text-muted);
  padding: 12px 12px 6px;
}

.sidebar-link {
  display: flex;
  align-items: center;
  gap: 8px;
  padding: 7px 12px;
  border-radius: 6px;
  color: var(--text-secondary);
  font-size: 0.9rem;
  transition: all var(--transition);
  text-decoration: none;
}

.sidebar-link:hover {
  background: var(--bg-hover);
  color: var(--text);
}

.sidebar-link.active {
  background: var(--accent-light);
  color: var(--accent);
  font-weight: 600;
}

.sidebar-link .nav-icon {
  font-size: 1rem;
  width: 20px;
  text-align: center;
  flex-shrink: 0;
}

/* ---------- Main Content ---------- */
.main-content {
  flex: 1;
  margin-left: var(--sidebar-width);
  padding: 40px 48px;
  max-width: 900px;
  min-width: 0;
}

/* ---------- Hero Section (Home page) ---------- */
.hero {
  background: var(--ob-bark);
  background-image:
    linear-gradient(rgba(232,168,40,.04) 1px, transparent 1px),
    linear-gradient(90deg, rgba(232,168,40,.04) 1px, transparent 1px);
  background-size: 16px 16px;
  border-radius: 16px;
  padding: 60px 48px;
  margin-bottom: 48px;
  color: #fff;
  text-align: center;
  position: relative;
  overflow: hidden;
}

.hero::before {
  content: '';
  position: absolute;
  top: 50%;
  left: 50%;
  transform: translate(-50%, -50%);
  width: 500px;
  height: 500px;
  background: radial-gradient(
    ellipse,
    rgba(232,168,40,.18) 0%,
    transparent 68%
  );
  pointer-events: none;
}

.hero-logo {
  width: 120px;
  height: auto;
  margin: 0 auto 24px;
  display: block;
  image-rendering: -webkit-optimize-contrast;
  image-rendering: pixelated;
  position: relative;
}

.hero h1 {
  font-family: var(--font-heading);
  font-size: 3.2rem;
  font-weight: 800;
  margin-bottom: 8px;
  line-height: 1.1;
  letter-spacing: -2px;
}
.hero h1 .hero-o {
  font-style: italic;
  font-weight: 300;
  color: var(--ob-amber);
}
.hero h1 .hero-beaver {
  font-weight: 800;
  color: #fff;
}

.hero .hero-slogan {
  font-family: var(--font-heading);
  font-style: italic;
  font-weight: 300;
  font-size: 1.15rem;
  color: var(--ob-amber);
  margin-bottom: 16px;
  opacity: 0.9;
}

.hero p {
  font-size: 1.05rem;
  opacity: 0.85;
  max-width: 600px;
  margin: 0 auto 32px;
  line-height: 1.6;
  color: var(--ob-belly);
}

.hero-buttons {
  display: flex;
  gap: 16px;
  justify-content: center;
  flex-wrap: wrap;
}

.btn {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  padding: 12px 28px;
  border-radius: 8px;
  font-size: 1rem;
  font-weight: 600;
  text-decoration: none;
  transition: all var(--transition);
  border: none;
  cursor: pointer;
}

.btn-primary {
  background: var(--ob-amber);
  color: var(--ob-bark);
}
.btn-primary:hover {
  background: #f0bc4c;
  color: var(--ob-bark);
  transform: translateY(-1px);
}

.btn-secondary {
  background: rgba(255,255,255,0.10);
  color: #fff;
  border: 1px solid rgba(255,255,255,0.3);
}
.btn-secondary:hover {
  background: rgba(255,255,255,0.25);
  color: #fff;
  transform: translateY(-1px);
}

/* ---------- Feature Cards (Home page) ---------- */
.features-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(260px, 1fr));
  gap: 20px;
  margin: 32px 0;
}

.feature-card {
  background: var(--bg-secondary);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 24px;
  transition: transform var(--transition), box-shadow var(--transition);
  text-decoration: none;
  color: var(--text);
  display: block;
}

.feature-card:hover {
  transform: translateY(-2px);
  box-shadow: var(--shadow-lg);
  color: var(--text);
  border-color: var(--ob-amber);
}

.feature-card .card-icon {
  font-size: 2rem;
  margin-bottom: 12px;
}

.feature-card h3 {
  font-family: var(--font-heading);
  font-size: 1.05rem;
  font-weight: 700;
  margin-bottom: 8px;
}

.feature-card p {
  font-size: 0.9rem;
  color: var(--text-secondary);
  line-height: 1.5;
}

/* ---------- Content Typography ---------- */
.content h1 {
  font-family: var(--font-heading);
  font-size: 2rem;
  font-weight: 800;
  margin-bottom: 12px;
  padding-bottom: 12px;
  border-bottom: 1px solid var(--border);
}

.content h2 {
  font-family: var(--font-heading);
  font-size: 1.5rem;
  font-weight: 700;
  margin-top: 48px;
  margin-bottom: 16px;
  padding-bottom: 8px;
  border-bottom: 1px solid var(--border);
}

.content h3 {
  font-family: var(--font-heading);
  font-size: 1.2rem;
  font-weight: 600;
  margin-top: 32px;
  margin-bottom: 12px;
}

.content h4 {
  font-size: 1.05rem;
  font-weight: 600;
  margin-top: 24px;
  margin-bottom: 8px;
}

.content p {
  margin-bottom: 16px;
  color: var(--text-secondary);
}

.content-note-compact {
  margin-bottom: 0;
  color: var(--text-secondary);
  font-size: 0.9rem;
}

.features-grid-spaced {
  margin-top: 32px;
}

.content ul, .content ol {
  margin-bottom: 16px;
  padding-left: 24px;
}

.content li {
  margin-bottom: 6px;
  color: var(--text-secondary);
}

.content hr {
  border: none;
  border-top: 1px solid var(--border);
  margin: 32px 0;
}

.content strong { color: var(--text); }

/* Inline code */
.content code {
  background: var(--bg-code);
  color: var(--code-text);
  padding: 2px 6px;
  border-radius: 4px;
  font-family: var(--font-mono);
  font-size: 0.875em;
}

/* Code blocks */
.code-block {
  position: relative;
  margin: 16px 0 24px;
  background: var(--bg-code);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  overflow: hidden;
}

.code-block-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 8px 16px;
  background: var(--bg-secondary);
  border-bottom: 1px solid var(--border);
  font-size: 0.8rem;
  color: var(--text-muted);
}

.code-block-lang { font-weight: 600; }

.copy-btn {
  background: none;
  border: 1px solid var(--border);
  border-radius: 4px;
  padding: 3px 10px;
  font-size: 0.75rem;
  color: var(--text-muted);
  cursor: pointer;
  transition: all var(--transition);
}
.copy-btn:hover {
  background: var(--bg-hover);
  color: var(--text);
}
.copy-btn.copied {
  color: #22c55e;
  border-color: #22c55e;
}

.code-block pre {
  margin: 0;
  padding: 16px;
  overflow-x: auto;
  font-family: var(--font-mono);
  font-size: 0.875rem;
  line-height: 1.6;
  color: var(--text);
}

/* CLI syntax highlight: command name amber, args river */
.code-block pre code .cli-cmd { color: var(--ob-amber); font-weight: 700; }
.code-block pre code .cli-arg { color: var(--ob-river); }
.code-block pre code .cli-flag { color: var(--text-muted); }

.code-block pre code {
  background: none;
  color: inherit;
  padding: 0;
  border-radius: 0;
  font-size: inherit;
}

/* ---------- Tables ---------- */
.content table {
  width: 100%;
  border-collapse: collapse;
  margin: 16px 0 24px;
  font-size: 0.9rem;
}

.content table th,
.content table td {
  padding: 10px 14px;
  border: 1px solid var(--border);
  text-align: left;
}

.content table th {
  background: var(--bg-secondary);
  font-weight: 600;
  color: var(--text);
}

.content table td {
  color: var(--text-secondary);
}

.content table tr:hover td {
  background: var(--bg-hover);
}

/* ---------- Callouts / Admonitions ---------- */
.callout {
  border-left: 4px solid var(--accent);
  background: var(--accent-light);
  padding: 16px 20px;
  border-radius: 0 var(--radius) var(--radius) 0;
  margin: 16px 0 24px;
  font-size: 0.925rem;
}

.callout.info { border-left-color: #3b82f6; background: rgba(59,130,246,0.08); }
.callout.warning { border-left-color: #f59e0b; background: rgba(245,158,11,0.08); }
.callout.danger { border-left-color: #ef4444; background: rgba(239,68,68,0.08); }
.callout.success { border-left-color: #22c55e; background: rgba(34,197,94,0.08); }

.callout p { margin: 0; color: var(--text); }
.callout strong { display: block; margin-bottom: 4px; }

/* ---------- Bottom Navigation ---------- */
.page-nav {
  display: flex;
  justify-content: space-between;
  margin-top: 64px;
  padding-top: 24px;
  border-top: 1px solid var(--border);
  gap: 16px;
}

.page-nav a {
  display: flex;
  flex-direction: column;
  padding: 16px 20px;
  border: 1px solid var(--border);
  border-radius: var(--radius);
  text-decoration: none;
  transition: all var(--transition);
  flex: 1;
  max-width: 50%;
}

.page-nav a:hover {
  border-color: var(--accent);
  background: var(--accent-light);
}

.page-nav .nav-label {
  font-size: 0.75rem;
  color: var(--text-muted);
  text-transform: uppercase;
  letter-spacing: 0.05em;
  margin-bottom: 4px;
}

.page-nav .nav-title {
  font-weight: 600;
  color: var(--text);
}

.page-nav .next { text-align: right; margin-left: auto; }

/* ---------- Footer ---------- */
.site-footer {
  margin-left: var(--sidebar-width);
  padding: 32px 48px;
  border-top: 1px solid var(--border);
  font-size: 0.85rem;
  color: var(--text-muted);
  display: flex;
  justify-content: space-between;
  align-items: center;
}

.footer-links {
  display: flex;
  gap: 20px;
}

.footer-links a {
  color: var(--text-muted);
  transition: color var(--transition);
}
.footer-links a:hover { color: var(--accent); }

/* ---------- Sidebar overlay (mobile) ---------- */
.sidebar-overlay {
  display: none;
  position: fixed;
  inset: 0;
  background: rgba(0,0,0,0.5);
  z-index: 899;
}

/* ---------- Responsive ---------- */
@media (max-width: 1024px) {
  .main-content { padding: 32px 24px; }
  .site-footer { padding: 24px; }
}

@media (max-width: 768px) {
  .header-inner { gap: 12px; }
  .sidebar {
    transform: translateX(-100%);
    width: 280px;
  }
  .sidebar.open { transform: translateX(0); }
  .sidebar-overlay.active { display: block; }
  .main-content { margin-left: 0; }
  .site-footer { margin-left: 0; flex-direction: column; gap: 12px; text-align: center; }
  .menu-toggle { display: block; }
  .search-box { width: 160px; }
  .header-left { gap: 10px; }
  .header-badge {
    padding: 5px 10px;
    font-size: 0.66rem;
    letter-spacing: 0.04em;
  }
  .docs-layout-preview::after {
    top: 22px;
    right: -86px;
    padding: 8px 82px;
    font-size: 0.64rem;
  }
  .hero { padding: 40px 24px; }
  .hero h1 { font-size: 2rem; }

  .page-nav { flex-direction: column; }
  .page-nav a { max-width: 100%; }
}

@media (max-width: 480px) {
  .search-box { display: none; }
  .header-badge {
    padding: 4px 8px;
    font-size: 0.58rem;
  }
  .hero h1 { font-size: 1.6rem; }
  .hero p { font-size: 1rem; }
  .features-grid { grid-template-columns: 1fr; }
}

/* ---------- Scroll-to-top ---------- */
.scroll-top {
  position: fixed;
  bottom: 24px;
  right: 24px;
  width: 40px;
  height: 40px;
  border-radius: 50%;
  background: var(--accent);
  color: #fff;
  border: none;
  cursor: pointer;
  font-size: 1.2rem;
  display: none;
  align-items: center;
  justify-content: center;
  z-index: 100;
  box-shadow: var(--shadow-lg);
  transition: opacity var(--transition), transform var(--transition);
}
.scroll-top.visible { display: flex; }
.scroll-top:hover { transform: scale(1.1); }

/* ---------- Anchor links for headers ---------- */
.content h2 .anchor,
.content h3 .anchor {
  opacity: 0;
  margin-left: 8px;
  color: var(--text-muted);
  font-weight: 400;
  transition: opacity var(--transition);
  text-decoration: none;
}

.content h2:hover .anchor,
.content h3:hover .anchor { opacity: 1; }

/* ---------- i18n Language Toggle ---------- */
[data-lang="en"] [data-zh] { display: none !important; }
[data-lang="zh"] [data-en] { display: none !important; }

.lang-toggle {
  background: none;
  border: 1px solid var(--border);
  border-radius: 6px;
  padding: 4px 10px;
  cursor: pointer;
  color: var(--text);
  font-size: 0.8rem;
  font-weight: 600;
  display: flex;
  align-items: center;
  gap: 4px;
  transition: background var(--transition), border-color var(--transition);
}
.lang-toggle:hover { background: var(--bg-hover); }

/* ---------- Architecture Diagram ---------- */
.arch-diagram {
  text-align: center;
  margin: 24px 0 32px;
}
.arch-diagram img {
  max-width: 100%;
  border-radius: var(--radius);
  border: 1px solid var(--border);
  box-shadow: var(--shadow);
}

.arch-image-zoomable {
  cursor: zoom-in;
}

.lightbox {
  display: none;
  position: fixed;
  inset: 0;
  z-index: 9999;
  background: rgba(0, 0, 0, 0.85);
  cursor: zoom-out;
  align-items: center;
  justify-content: center;
}

.lightbox-image {
  max-width: 92vw;
  max-height: 92vh;
  border-radius: 8px;
  box-shadow: 0 8px 40px rgba(0, 0, 0, 0.5);
}

/* ---------- Print ---------- */
@media print {
  .site-header, .sidebar, .sidebar-overlay, .scroll-top, .theme-toggle, .page-nav { display: none !important; }
  .main-content { margin-left: 0; padding: 0; }
  .site-footer { margin-left: 0; }
}