:root {
  color-scheme: light dark;
  --bg: #ffffff;
  --panel: #f8fafc;
  --text: #111827;
  --text-2: #475569;
  --line: #cbd5e1;
  --accent: #2563eb;
}
@media (prefers-color-scheme: dark) {
  :root {
    --bg: #111827;
    --panel: #1f2937;
    --text: #f9fafb;
    --text-2: #cbd5e1;
    --line: #475569;
    --accent: #60a5fa;
  }
}
* { box-sizing: border-box; }
body {
  margin: 0;
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", "PingFang SC",
    "Hiragino Sans GB", "Microsoft YaHei", sans-serif;
  font-size: 16px;
  line-height: 1.75;
  color: var(--text);
  background: var(--bg);
}
main { max-width: 720px; margin: 0 auto; padding: 40px 20px 80px; }
h1 { font-size: 1.7rem; line-height: 1.3; margin: 0 0 8px; }
h2 { font-size: 1.2rem; margin: 32px 0 8px; }
p, li { color: var(--text); }
a { color: var(--accent); }
.muted { color: var(--text-2); font-size: .9rem; }
.lang-nav { font-size: .9rem; margin-bottom: 24px; }
.lang-nav a { margin-right: 12px; }
.card {
  background: var(--panel);
  border: 1px solid var(--line);
  border-radius: 10px;
  padding: 16px 20px;
  margin: 20px 0;
}
ul { padding-left: 22px; }
hr { border: none; border-top: 1px solid var(--line); margin: 32px 0; }
code {
  font-family: ui-monospace, SFMono-Regular, Menlo, Consolas, monospace;
  font-size: .85em;
  background: var(--panel);
  border: 1px solid var(--line);
  border-radius: 4px;
  padding: 1px 5px;
  word-break: break-all;
}
footer { margin-top: 48px; font-size: .85rem; color: var(--text-2); }
@media (max-width: 480px) {
  main { padding: 24px 16px 56px; }
  body { font-size: 15px; }
}