:root {
  color-scheme: light dark;
  --bg: #f6f7f9;
  --surface: #fff;
  --text: #1f2328;
  --muted: #59636e;
  --border: #d8dee4;
  --accent: #1677ff;
  font-family: system-ui, -apple-system, "Segoe UI", "PingFang SC", "Microsoft YaHei", sans-serif;
  line-height: 1.7;
}
@media (prefers-color-scheme: dark) {
  :root { --bg: #0d1117; --surface: #161b22; --text: #e6edf3; --muted: #9198a1; --border: #30363d; --accent: #4c8dff; }
}
* { box-sizing: border-box; }
body { margin: 0; background: var(--bg); color: var(--text); }
a { color: var(--accent); }
.top { display: flex; flex-wrap: wrap; gap: 8px 24px; align-items: center; justify-content: space-between; max-width: 860px; margin: 0 auto; padding: 16px; }
.brand { font-weight: 600; color: var(--text); text-decoration: none; }
nav { display: flex; flex-wrap: wrap; gap: 16px; }
nav a { text-decoration: none; }
main { max-width: 860px; margin: 0 auto; padding: 8px 16px 48px; }
section, article { background: var(--surface); border: 1px solid var(--border); border-radius: 10px; padding: 24px 28px; margin-bottom: 16px; }
h1 { font-size: 26px; margin: 0 0 12px; }
h2 { font-size: 18px; margin: 28px 0 8px; }
section > h2:first-child, article > h2:first-child { margin-top: 0; }
.hero h1 { font-size: 30px; }
.meta { color: var(--muted); margin-top: 0; }
.button { display: inline-block; padding: 8px 20px; border-radius: 6px; background: var(--accent); color: #fff; text-decoration: none; }
code { font-size: 0.92em; padding: 1px 5px; border-radius: 4px; background: var(--bg); border: 1px solid var(--border); }
ul { padding-left: 1.3em; }
footer { max-width: 860px; margin: 0 auto; padding: 0 16px 32px; color: var(--muted); font-size: 13px; }
@media (max-width: 480px) { section, article { padding: 18px 16px; } }