:root {
  --bg: #fbfbfa; --fg: #24292f; --muted: #6e7781; --accent: #b45309;
  --accent-soft: #fef3c7; --border: #e5e7eb; --code-bg: #f3f4f6; --card: #ffffff;
}
@media (prefers-color-scheme: dark) {
  :root {
    --bg: #0d1117; --fg: #e6edf3; --muted: #8b949e; --accent: #f0a94c;
    --accent-soft: #2a2013; --border: #30363d; --code-bg: #161b22; --card: #161b22;
  }
}
* { box-sizing: border-box; }
body { margin: 0; background: var(--bg); color: var(--fg);
  font-family: -apple-system, "Segoe UI", "PingFang SC", "Microsoft YaHei", "Noto Sans CJK SC", sans-serif;
  line-height: 1.75; font-size: 16px; }
a { color: var(--accent); text-decoration: none; }
a:hover { text-decoration: underline; }
.layout { display: flex; min-height: 100vh; }
.sidebar { width: 264px; flex: none; padding: 24px 18px; border-right: 1px solid var(--border);
  position: sticky; top: 0; height: 100vh; overflow-y: auto; background: var(--card); }
.sidebar h1 { font-size: 17px; margin: 0 0 4px; }
.sidebar .sub { font-size: 12px; color: var(--muted); margin-bottom: 18px; }
.sidebar nav a { display: block; padding: 7px 10px; border-radius: 6px; font-size: 14px;
  color: var(--fg); margin-bottom: 2px; }
.sidebar nav a:hover { background: var(--code-bg); text-decoration: none; }
.sidebar nav a.active { background: var(--accent-soft); color: var(--accent); font-weight: 600; }
.sidebar .nav-title { font-size: 12px; color: var(--muted); margin: 16px 0 6px; padding-left: 10px;
  text-transform: uppercase; letter-spacing: .05em; }
.main { flex: 1; min-width: 0; padding: 40px 48px 80px; }
.content { max-width: 780px; margin: 0 auto; }
.content h1 { font-size: 28px; border-bottom: 1px solid var(--border); padding-bottom: 12px; margin-top: 0; }
.content h2 { font-size: 21px; margin-top: 2em; border-bottom: 1px solid var(--border); padding-bottom: 6px; }
.content h3 { font-size: 17px; margin-top: 1.6em; }
.content p { margin: .9em 0; }
.content blockquote { margin: 1em 0; padding: 2px 18px; border-left: 4px solid var(--accent);
  background: var(--accent-soft); border-radius: 0 6px 6px 0; color: var(--fg); }
.content blockquote p { margin: .6em 0; }
.content code { background: var(--code-bg); padding: 2px 6px; border-radius: 4px;
  font-family: "Cascadia Code", Consolas, monospace; font-size: .88em; }
.content pre { background: var(--code-bg); padding: 14px 16px; border-radius: 8px;
  overflow-x: auto; border: 1px solid var(--border); }
.content pre code { background: none; padding: 0; }
.content table { border-collapse: collapse; width: 100%; margin: 1em 0; font-size: 15px; }
.content th, .content td { border: 1px solid var(--border); padding: 8px 12px; text-align: left; }
.content th { background: var(--code-bg); font-weight: 600; }
.content tr:nth-child(even) td { background: var(--card); }
.content ul, .content ol { padding-left: 1.6em; }
.content li { margin: .35em 0; }
.content hr { border: none; border-top: 1px solid var(--border); margin: 2em 0; }
.hero h1 { font-size: 32px; margin: 0 0 8px; }
.hero .desc { color: var(--muted); margin-bottom: 28px; }
.cards { display: grid; grid-template-columns: repeat(auto-fill, minmax(300px, 1fr)); gap: 16px; margin: 20px 0; }
.card { display: block; background: var(--card); border: 1px solid var(--border); border-radius: 10px;
  padding: 18px 20px; color: var(--fg); transition: border-color .15s, box-shadow .15s; }
.card:hover { border-color: var(--accent); box-shadow: 0 2px 10px rgba(0,0,0,.10); text-decoration: none; }
.card h3 { margin: 0 0 6px; font-size: 16px; color: var(--fg); }
.card p { margin: 0; color: var(--muted); font-size: 14px; }
.card .tag { display: inline-block; font-size: 12px; color: var(--accent); background: var(--accent-soft);
  border-radius: 20px; padding: 1px 10px; margin-top: 10px; }
.map { margin: 26px 0; }
.map .part { font-weight: 700; margin: 14px 0 6px; }
.map .chips { display: flex; flex-wrap: wrap; gap: 8px; }
.chip { border: 1px solid var(--border); border-radius: 20px; padding: 3px 12px; font-size: 13px; }
.chip.done { background: var(--accent-soft); border-color: var(--accent); color: var(--accent); }
.pager { display: flex; justify-content: space-between; gap: 12px; margin-top: 40px;
  border-top: 1px solid var(--border); padding-top: 16px; font-size: 14px; }
.footer { margin-top: 48px; color: var(--muted); font-size: 13px; border-top: 1px solid var(--border);
  padding-top: 16px; }