:root {
  --bg: #ffffff;
  --surface: #f8f9fb;
  --border: #e4e7eb;
  --text: #1a1d21;
  --text-muted: #5a6470;
  --accent: #2b6cb0;
  --accent-hover: #1e4f8a;
  --code-bg: #f3f5f7;
  --code-text: #1a1d21;
  --rule-bg: #eef5fb;
  --rule-border: #b8d4f0;

  --font-sans: "Inter", "Segoe UI", system-ui, -apple-system, sans-serif;
  --font-mono: "SFMono-Regular", "Consolas", "Menlo", monospace;

  --max-width: 1200px;
  --sidebar-width: 260px;
}

* { box-sizing: border-box; }

html { scroll-behavior: smooth; }

body {
  margin: 0;
  font-family: var(--font-sans);
  font-size: 16px;
  line-height: 1.65;
  color: var(--text);
  background-color: var(--bg);
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
  display: flex;
  flex-direction: column;
  min-height: 100vh;
}

/* Header */
.site-header {
  border-bottom: 1px solid var(--border);
  background-color: var(--bg);
  position: sticky;
  top: 0;
  z-index: 10;
}

.header-inner {
  max-width: var(--max-width);
  margin: 0 auto;
  padding: 0.85rem 1.5rem;
  display: flex;
  align-items: center;
  gap: 0.75rem;
}

.site-logo {
  display: flex;
  align-items: center;
  text-decoration: none;
  gap: 0.5rem;
}

.site-logo img {
  width: 28px;
  height: 28px;
}

.site-title {
  font-size: 1.1rem;
  font-weight: 600;
  color: var(--text);
}

.header-nav {
  margin-left: auto;
  display: flex;
  gap: 1.25rem;
}

.header-nav a {
  color: var(--text-muted);
  text-decoration: none;
  font-size: 0.9rem;
  font-weight: 500;
  transition: color 0.15s;
}

.header-nav a:hover { color: var(--accent); }

/* Layout */
.layout {
  max-width: var(--max-width);
  margin: 0 auto;
  display: grid;
  grid-template-columns: var(--sidebar-width) 1fr;
  gap: 2.5rem;
  padding: 2.5rem 1.5rem;
  flex: 1 0 auto;
  width: 100%;
}

/* Sidebar */
.sidebar {
  position: sticky;
  top: 4rem;
  align-self: start;
  max-height: calc(100vh - 5rem);
  overflow-y: auto;
}

.sidebar-title {
  font-size: 0.95rem;
  font-weight: 600;
  margin: 0 0 0.75rem;
  color: var(--text);
}

.sidebar-section {
  font-size: 0.75rem;
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: 0.06em;
  color: var(--text-muted);
  margin: 1.5rem 0 0.5rem;
}

.sidebar-section:first-child { margin-top: 0; }

.sidebar ul {
  list-style: none;
  margin: 0;
  padding: 0;
  display: flex;
  flex-direction: column;
  gap: 2px;
}

.sidebar a {
  display: block;
  padding: 0.35rem 0.6rem;
  border-radius: 6px;
  color: var(--text-muted);
  text-decoration: none;
  font-size: 0.9rem;
  transition: background-color 0.15s, color 0.15s;
}

.sidebar a:hover {
  background-color: var(--surface);
  color: var(--text);
}

.sidebar a.active {
  background-color: var(--surface);
  color: var(--accent);
  font-weight: 500;
}

/* Content */
.content { min-width: 0; }

.breadcrumb {
  font-size: 0.85rem;
  color: var(--text-muted);
  margin-bottom: 1rem;
}

.breadcrumb a {
  color: var(--accent);
  text-decoration: none;
}

.breadcrumb a:hover { text-decoration: underline; }

.content h1 {
  font-size: 2rem;
  font-weight: 700;
  margin: 0 0 0.5rem;
  letter-spacing: -0.02em;
}

.content h2 {
  font-size: 1.35rem;
  font-weight: 600;
  margin: 2rem 0 0.75rem;
  padding-bottom: 0.4rem;
  border-bottom: 1px solid var(--border);
}

.content h3 {
  font-size: 1.1rem;
  font-weight: 600;
  margin: 1.5rem 0 0.5rem;
}

.content p { margin: 0.75rem 0; }

.content ul, .content ol { margin: 0.75rem 0; padding-left: 1.5rem; }

.content li { margin: 0.3rem 0; }

.content strong { font-weight: 600; }

.content code {
  font-family: var(--font-mono);
  font-size: 0.875em;
  background-color: var(--code-bg);
  padding: 0.15em 0.4em;
  border-radius: 4px;
  color: var(--code-text);
}

.content pre {
  background-color: var(--code-bg);
  border: 1px solid var(--border);
  padding: 1rem 1.25rem;
  border-radius: 8px;
  overflow-x: auto;
  margin: 1rem 0;
}

.content pre code {
  background: none;
  padding: 0;
  font-size: 0.875rem;
  line-height: 1.5;
}

.content a {
  color: var(--accent);
  text-decoration: none;
}

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

/* Rule box */
.rule {
  background-color: var(--rule-bg);
  border: 1px solid var(--rule-border);
  border-radius: 8px;
  padding: 0.75rem 1rem;
  margin: 1rem 0;
  font-size: 0.95rem;
}

.rule strong { color: var(--accent); }

/* Tables */
.table-wrap {
  overflow-x: auto;
  margin: 1rem 0;
}

.content table {
  border-collapse: collapse;
  width: 100%;
  font-size: 0.9rem;
}

.content th, .content td {
  text-align: left;
  padding: 0.5rem 0.75rem;
  border: 1px solid var(--border);
}

.content th {
  background-color: var(--surface);
  font-weight: 600;
}

.content tr:nth-child(even) td {
  background-color: var(--surface);
}

/* Navigation links */
.next-links, .page-navigation {
  display: flex;
  justify-content: space-between;
  gap: 1rem;
  margin-top: 2.5rem;
  padding-top: 1.5rem;
  border-top: 1px solid var(--border);
}

.next-links a, .page-navigation a {
  color: var(--accent);
  text-decoration: none;
  font-weight: 500;
  font-size: 0.9rem;
}

.next-links a:hover, .page-navigation a:hover {
  color: var(--accent-hover);
  text-decoration: underline;
}

/* Footer */
.site-footer {
  border-top: 1px solid var(--border);
  flex-shrink: 0;
}

.site-footer-inner {
  max-width: var(--max-width);
  margin: 0 auto;
  padding: 1.5rem;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 1rem;
}

.site-footer p {
  margin: 0;
  color: var(--text-muted);
  font-size: 0.85rem;
}

.site-footer a {
  color: var(--text-muted);
  text-decoration: none;
  font-size: 0.85rem;
}

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

/* Responsive */
@media (max-width: 768px) {
  .layout {
    grid-template-columns: 1fr;
    gap: 1rem;
    padding: 1.5rem 1rem;
  }
  .sidebar {
    position: static;
    max-height: none;
    border-bottom: 1px solid var(--border);
    padding-bottom: 1rem;
  }
  .header-nav { gap: 0.75rem; }
  .next-links, .page-navigation {
    flex-direction: column;
    gap: 0.5rem;
  }
}