:root {
  --bg: #ffffff;
  --fg: #1a1a1a;
  --muted: #666666;
  --border: #e5e5e5;
  --accent: #2563eb;
  --code-bg: #f5f5f5;
  --sidebar-bg: #fafafa;
}

@media (prefers-color-scheme: dark) {
  :root {
    --bg: #16171a;
    --fg: #e6e6e6;
    --muted: #9a9a9a;
    --border: #2a2b2f;
    --accent: #6ea8fe;
    --code-bg: #1f2023;
    --sidebar-bg: #1b1c1f;
  }
}

* { box-sizing: border-box; }

body {
  margin: 0;
  background: var(--bg);
  color: var(--fg);
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Helvetica, Arial, sans-serif;
  line-height: 1.6;
}

.layout {
  display: flex;
  min-height: 100vh;
}

.sidebar {
  width: 220px;
  flex-shrink: 0;
  background: var(--sidebar-bg);
  border-right: 1px solid var(--border);
  padding: 24px 16px;
}

.sidebar h1 {
  font-size: 15px;
  font-weight: 600;
  margin: 0 0 16px 8px;
  color: var(--muted);
  text-transform: uppercase;
  letter-spacing: 0.03em;
}

.sidebar ul {
  list-style: none;
  margin: 0;
  padding: 0;
}

.sidebar a {
  display: block;
  padding: 8px;
  border-radius: 6px;
  color: var(--fg);
  text-decoration: none;
  font-size: 15px;
}

.sidebar a:hover {
  background: var(--border);
}

.sidebar a.active {
  background: var(--accent);
  color: #fff;
}

.content {
  flex: 1;
  max-width: 760px;
  padding: 40px 32px 80px;
}

.loading, .error {
  color: var(--muted);
}

.content h1 { font-size: 28px; margin-top: 0; }
.content h2 { font-size: 21px; margin-top: 2em; }
.content h3 { font-size: 17px; }

.content pre {
  background: var(--code-bg);
  padding: 12px 16px;
  border-radius: 6px;
  overflow-x: auto;
}

.content code {
  background: var(--code-bg);
  padding: 2px 5px;
  border-radius: 4px;
  font-size: 0.9em;
}

.content pre code {
  background: none;
  padding: 0;
}

.content blockquote {
  border-left: 3px solid var(--accent);
  margin: 1em 0;
  padding: 2px 16px;
  color: var(--muted);
}

.content table {
  border-collapse: collapse;
  width: 100%;
}

.content th, .content td {
  border: 1px solid var(--border);
  padding: 6px 10px;
  text-align: left;
}

.content a { color: var(--accent); }

@media (max-width: 640px) {
  .layout { flex-direction: column; }
  .sidebar {
    width: auto;
    border-right: none;
    border-bottom: 1px solid var(--border);
  }
  .sidebar ul { display: flex; gap: 8px; }
  .content { padding: 24px 20px 60px; }
}