/* ARuVR Learn — Modern Knowledge Base */

@import url('https://fonts.googleapis.com/css2?family=Inter:wght@400;500;600;700&display=swap');

:root {
  --color-brand: #2f90c5;
  --color-brand-hover: #2578a6;
  --color-brand-light: #4aa8d8;
  --color-brand-bg: rgba(47, 144, 197, 0.08);
  --color-text: #0f172a;
  --color-text-secondary: #475569;
  --color-text-muted: #94a3b8;
  --color-bg: #ffffff;
  --color-bg-subtle: #f8fafc;
  --color-bg-muted: #f1f5f9;
  --color-border: #e2e8f0;
  --color-border-light: #f1f5f9;
  --sidebar-width: 260px;
  --header-height: 60px;
  --content-max-width: 768px;
  --radius-sm: 6px;
  --radius-md: 8px;
  --radius-lg: 12px;
  --shadow-sm: 0 1px 2px rgba(0,0,0,0.05);
  --shadow-md: 0 4px 12px rgba(0,0,0,0.08);
  --transition: 150ms ease;
}

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

html { scroll-behavior: smooth; }

body {
  font-family: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', sans-serif;
  color: var(--color-text);
  background: var(--color-bg);
  line-height: 1.7;
  font-size: 15px;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
}

/* ─── Header ─── */
.site-header {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  height: var(--header-height);
  background: rgba(255,255,255,0.85);
  backdrop-filter: blur(12px);
  -webkit-backdrop-filter: blur(12px);
  border-bottom: 1px solid var(--color-border);
  z-index: 100;
}

.header-inner {
  max-width: 1440px;
  margin: 0 auto;
  height: 100%;
  display: flex;
  align-items: center;
  padding: 0 24px;
  gap: 32px;
}

.logo img { height: 26px; display: block; }

.top-nav { display: flex; gap: 4px; margin-left: auto; }

.top-nav a {
  color: var(--color-text-secondary);
  text-decoration: none;
  font-size: 13.5px;
  font-weight: 500;
  padding: 6px 12px;
  border-radius: var(--radius-sm);
  transition: color var(--transition), background var(--transition);
}

.top-nav a:hover {
  color: var(--color-text);
  background: var(--color-bg-muted);
}

.mobile-menu-btn {
  display: none;
  background: none;
  border: none;
  font-size: 20px;
  cursor: pointer;
  color: var(--color-text);
  padding: 4px;
}

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

/* ─── Sidebar ─── */
.sidebar {
  width: var(--sidebar-width);
  flex-shrink: 0;
  padding: 20px 16px;
  border-right: 1px solid var(--color-border);
  position: fixed;
  top: var(--header-height);
  bottom: 0;
  overflow-y: auto;
  background: var(--color-bg);
  scrollbar-width: thin;
  scrollbar-color: var(--color-border) transparent;
}

.sidebar::-webkit-scrollbar { width: 4px; }
.sidebar::-webkit-scrollbar-track { background: transparent; }
.sidebar::-webkit-scrollbar-thumb { background: var(--color-border); border-radius: 4px; }

.sidebar-group { margin-bottom: 24px; }

.sidebar-group h3 {
  font-size: 11px;
  font-weight: 600;
  color: var(--color-text-muted);
  text-transform: uppercase;
  letter-spacing: 0.06em;
  margin-bottom: 4px;
  padding: 6px 10px 4px;
}

.sidebar-group ul { list-style: none; }

.sidebar-group a {
  display: block;
  padding: 5px 10px;
  color: var(--color-text-secondary);
  text-decoration: none;
  font-size: 13.5px;
  font-weight: 450;
  border-radius: var(--radius-sm);
  transition: all var(--transition);
  margin: 1px 0;
}

.sidebar-group a:hover {
  background: var(--color-bg-muted);
  color: var(--color-text);
}

.sidebar-group a.active {
  color: var(--color-brand);
  font-weight: 550;
  background: var(--color-brand-bg);
}

/* ─── Content ─── */
.content {
  flex: 1;
  min-width: 0;
  max-width: var(--content-max-width);
  margin-left: var(--sidebar-width);
  padding: 40px 56px 80px;
}

.content h1 {
  font-size: 30px;
  font-weight: 700;
  line-height: 1.2;
  margin-bottom: 8px;
  letter-spacing: -0.025em;
  color: var(--color-text);
}

.content h1 + p { color: var(--color-text-secondary); }

.content h2 {
  font-size: 22px;
  font-weight: 650;
  margin-top: 48px;
  margin-bottom: 12px;
  padding-top: 24px;
  border-top: 1px solid var(--color-border-light);
  letter-spacing: -0.015em;
}

.content h2:first-child { margin-top: 0; padding-top: 0; border: none; }

.content h3 {
  font-size: 17px;
  font-weight: 600;
  margin-top: 32px;
  margin-bottom: 8px;
  letter-spacing: -0.01em;
}

.content h4 {
  font-size: 15px;
  font-weight: 600;
  margin-top: 24px;
  margin-bottom: 8px;
}

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

.content a {
  color: var(--color-brand);
  text-decoration: none;
  font-weight: 500;
  transition: color var(--transition);
}

.content a:hover { color: var(--color-brand-hover); text-decoration: underline; }

.content .hero-action { color: white; }
.content .hero-action:hover { color: white; text-decoration: none; }
.content .hero-action.alt { color: var(--color-text); }
.content .hero-action.alt:hover { color: var(--color-text); text-decoration: none; }

.content img {
  max-width: 100%;
  height: auto;
  border-radius: var(--radius-lg);
  border: 1px solid var(--color-border);
  margin: 20px 0;
  box-shadow: var(--shadow-sm);
}

.content video {
  max-width: 100%;
  height: auto;
  border-radius: var(--radius-lg);
  border: 1px solid var(--color-border);
  margin: 20px 0;
  box-shadow: var(--shadow-sm);
}

.content ul, .content ol { padding-left: 22px; margin-bottom: 16px; }

.content li { margin-bottom: 6px; }

.content li::marker { color: var(--color-text-muted); }

.content blockquote {
  margin: 20px 0;
  padding: 14px 20px;
  border-left: 3px solid var(--color-brand);
  background: var(--color-bg-subtle);
  border-radius: 0 var(--radius-md) var(--radius-md) 0;
  color: var(--color-text-secondary);
}

.content code {
  font-family: 'SF Mono', 'JetBrains Mono', Monaco, Menlo, Consolas, monospace;
  font-size: 13px;
  background: var(--color-bg-muted);
  padding: 2px 6px;
  border-radius: 4px;
  color: var(--color-text);
}

.content pre {
  margin: 20px 0;
  padding: 18px 22px;
  background: #0f172a;
  color: #e2e8f0;
  border-radius: var(--radius-lg);
  overflow-x: auto;
  line-height: 1.6;
  box-shadow: var(--shadow-md);
}

.content pre code {
  background: none;
  padding: 0;
  color: inherit;
  font-size: 13px;
}

.content table {
  width: 100%;
  border-collapse: collapse;
  margin: 20px 0;
  font-size: 14px;
  border-radius: var(--radius-md);
  overflow: hidden;
  border: 1px solid var(--color-border);
}

.content th, .content td {
  padding: 10px 16px;
  text-align: left;
  border-bottom: 1px solid var(--color-border-light);
}

.content th {
  background: var(--color-bg-subtle);
  font-weight: 600;
  font-size: 12px;
  text-transform: uppercase;
  letter-spacing: 0.04em;
  color: var(--color-text-secondary);
}

.content tr:last-child td { border-bottom: none; }

.content strong { font-weight: 600; }

.content hr {
  margin: 40px 0;
  border: none;
  border-top: 1px solid var(--color-border-light);
}

/* ─── Custom Blocks ─── */
.custom-block {
  margin: 20px 0;
  padding: 16px 20px;
  border-radius: var(--radius-md);
  border-left: 3px solid;
  font-size: 14px;
}

.custom-block-title {
  font-weight: 600;
  font-size: 13px;
  text-transform: uppercase;
  letter-spacing: 0.03em;
  margin-bottom: 6px;
}

.custom-block p:last-child { margin-bottom: 0; }

.custom-block.tip { background: #f0fdf4; border-color: #22c55e; }
.custom-block.tip .custom-block-title { color: #16a34a; }

.custom-block.info { background: #eff6ff; border-color: #3b82f6; }
.custom-block.info .custom-block-title { color: #2563eb; }

.custom-block.warning { background: #fffbeb; border-color: #f59e0b; }
.custom-block.warning .custom-block-title { color: #d97706; }

.custom-block.danger { background: #fef2f2; border-color: #ef4444; }
.custom-block.danger .custom-block-title { color: #dc2626; }

.custom-block.details { border-color: var(--color-border); background: var(--color-bg-subtle); }
.custom-block.details summary { font-weight: 600; cursor: pointer; }

/* ─── Home Page ─── */
.content.home-page {
  max-width: none;
}

.hero {
  text-align: center;
  padding: 64px 0 48px;
  max-width: 720px;
  margin: 0 auto;
}

.hero h1 {
  font-size: 44px;
  font-weight: 750;
  line-height: 1.1;
  margin-bottom: 16px;
  letter-spacing: -0.03em;
  border: none;
  padding: 0;
}

.hero-name {
  background: linear-gradient(135deg, var(--color-brand), var(--color-brand-light));
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}

.hero-tagline {
  font-size: 17px;
  color: var(--color-text-secondary);
  max-width: 520px;
  margin: 0 auto 32px;
  line-height: 1.6;
}

.hero-actions {
  display: flex;
  gap: 12px;
  justify-content: center;
}

.hero-action {
  display: inline-flex;
  align-items: center;
  padding: 10px 24px;
  border-radius: var(--radius-md);
  font-weight: 600;
  font-size: 14px;
  text-decoration: none;
  transition: all var(--transition);
}

.hero-action.brand {
  background: var(--color-brand);
  color: white;
  box-shadow: 0 1px 3px rgba(47,144,197,0.3);
}

.hero-action.brand:hover {
  background: var(--color-brand-hover);
  box-shadow: 0 4px 12px rgba(47,144,197,0.3);
  transform: translateY(-1px);
  text-decoration: none;
}

.hero-action.alt {
  background: var(--color-bg);
  color: var(--color-text);
  border: 1px solid var(--color-border);
}

.hero-action.alt:hover {
  background: var(--color-bg-subtle);
  border-color: var(--color-text-muted);
  text-decoration: none;
}

.features {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
  gap: 16px;
  max-width: 960px;
  margin: 0 auto;
  padding: 8px 0 48px;
}

.feature-card {
  display: block;
  padding: 24px;
  background: var(--color-bg);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-lg);
  text-decoration: none;
  color: var(--color-text);
  transition: all var(--transition);
}

.feature-card:hover {
  border-color: var(--color-brand-light);
  box-shadow: var(--shadow-md);
  transform: translateY(-2px);
  text-decoration: none;
}

.feature-card h3 {
  font-size: 15px;
  font-weight: 600;
  margin-bottom: 6px;
  margin-top: 0;
  color: var(--color-text);
}

.feature-card p {
  font-size: 13.5px;
  color: var(--color-text-secondary);
  margin: 0;
  line-height: 1.5;
}

.feature-icon {
  width: 40px;
  height: 40px;
  display: flex;
  align-items: center;
  justify-content: center;
  background: var(--color-brand-bg);
  border-radius: var(--radius-md);
  color: var(--color-brand);
  margin-bottom: 14px;
}

.feature-card:hover .feature-icon {
  background: var(--color-brand);
  color: white;
  transition: all var(--transition);
}

.hero-badge {
  display: inline-block;
  font-size: 12px;
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: 0.08em;
  color: var(--color-brand);
  background: var(--color-brand-bg);
  padding: 4px 14px;
  border-radius: 100px;
  margin-bottom: 20px;
}

/* ─── Search ─── */
.search-wrapper {
  position: relative;
  flex: 0 1 360px;
  margin-left: auto;
}

.search-icon {
  position: absolute;
  left: 12px;
  top: 50%;
  transform: translateY(-50%);
  color: var(--color-text-muted);
  pointer-events: none;
}

.search-input {
  width: 100%;
  padding: 7px 40px 7px 36px;
  font-size: 13.5px;
  font-family: inherit;
  border: 1px solid var(--color-border);
  border-radius: var(--radius-md);
  background: var(--color-bg-subtle);
  color: var(--color-text);
  outline: none;
  transition: all var(--transition);
}

.search-input::placeholder {
  color: var(--color-text-muted);
}

.search-input:focus {
  border-color: var(--color-brand-light);
  background: var(--color-bg);
  box-shadow: 0 0 0 3px rgba(47, 144, 197, 0.12);
}

.search-kbd {
  position: absolute;
  right: 10px;
  top: 50%;
  transform: translateY(-50%);
  font-family: inherit;
  font-size: 11px;
  font-weight: 500;
  color: var(--color-text-muted);
  background: var(--color-bg);
  border: 1px solid var(--color-border);
  border-radius: 4px;
  padding: 1px 6px;
  pointer-events: none;
}

.search-input:focus ~ .search-kbd {
  display: none;
}

.search-results {
  display: none;
  position: absolute;
  top: calc(100% + 6px);
  left: 0;
  right: 0;
  background: var(--color-bg);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-lg);
  box-shadow: 0 12px 40px rgba(0,0,0,0.12);
  max-height: 420px;
  overflow-y: auto;
  z-index: 200;
  padding: 6px;
}

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

.search-result-item {
  display: block;
  padding: 10px 14px;
  border-radius: var(--radius-md);
  text-decoration: none;
  color: var(--color-text);
  transition: background var(--transition);
}

.search-result-item:hover {
  background: var(--color-bg-muted);
  text-decoration: none;
}

.search-result-section {
  display: block;
  font-size: 10.5px;
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: 0.05em;
  color: var(--color-brand);
  margin-bottom: 2px;
}

.search-result-title {
  display: block;
  font-size: 14px;
  font-weight: 600;
  color: var(--color-text);
  margin-bottom: 2px;
}

.search-result-preview {
  display: block;
  font-size: 12.5px;
  color: var(--color-text-secondary);
  line-height: 1.4;
}

.search-result-preview mark {
  background: rgba(47, 144, 197, 0.15);
  color: var(--color-brand);
  padding: 0 2px;
  border-radius: 2px;
}

.search-empty {
  padding: 24px 14px;
  text-align: center;
  font-size: 13px;
  color: var(--color-text-muted);
}

/* ─── Footer ─── */
.site-footer {
  margin-left: var(--sidebar-width);
  padding: 24px 56px;
  border-top: 1px solid var(--color-border-light);
}

.site-footer p {
  font-size: 12.5px;
  color: var(--color-text-muted);
}

/* ─── Responsive ─── */
@media (max-width: 768px) {
  .sidebar {
    display: none;
    position: fixed;
    top: var(--header-height);
    left: 0;
    bottom: 0;
    width: 280px;
    z-index: 99;
    background: var(--color-bg);
    box-shadow: 4px 0 20px rgba(0,0,0,0.1);
  }

  .sidebar.open { display: block; }

  .mobile-menu-btn { display: block; }

  .top-nav { display: none; }

  .search-wrapper { flex: 1; margin-left: 0; margin-right: 12px; }

  .content { margin-left: 0; padding: 24px 20px 48px; }

  .site-footer { margin-left: 0; padding: 24px 20px; }

  .hero { padding: 40px 0 32px; }
  .hero h1 { font-size: 28px; }
  .hero-tagline { font-size: 15px; }

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