:root{--bg:#fbfaf7;--fg:#1c1b18;--muted:#6b675f;--line:#e6e2d9;--accent:#1f4f8f;--max:760px}
@media (prefers-color-scheme:dark){:root{--bg:#141412;--fg:#ebe8e1;--muted:#a19c91;--line:#2c2b27;--accent:#7fb0ec}}
*{box-sizing:border-box}html{-webkit-text-size-adjust:100%}
body{margin:0;background:var(--bg);color:var(--fg);font:17px/1.65 -apple-system,BlinkMacSystemFont,"PingFang SC","Helvetica Neue","Noto Sans SC",sans-serif}
header,main,footer{max-width:var(--max);margin:0 auto;padding:0 20px}
header{display:flex;align-items:baseline;justify-content:space-between;gap:16px;padding-top:28px;padding-bottom:12px;border-bottom:1px solid var(--line);flex-wrap:wrap}
.brand{font-weight:700;text-decoration:none;color:var(--fg);letter-spacing:.01em}
.brand small{display:block;font-weight:400;color:var(--muted);font-size:13px}
nav a{color:var(--muted);text-decoration:none;margin-left:18px;font-size:15px}nav a:hover,nav a[aria-current]{color:var(--fg)}
main{padding-top:40px;padding-bottom:64px}
h1{font-size:34px;line-height:1.2;margin:0 0 8px;letter-spacing:-.01em}h1 .zh{display:block;font-size:22px;font-weight:500;color:var(--muted);margin-top:6px}
h2{font-size:20px;margin:40px 0 10px}
p{margin:0 0 14px}.lead{font-size:19px;color:var(--muted)}
a{color:var(--accent)}
dl{display:grid;grid-template-columns:max-content 1fr;gap:6px 18px;margin:0}dt{color:var(--muted)}dd{margin:0}
@media (max-width:480px){dl{grid-template-columns:1fr}dt{margin-top:8px}}
footer{border-top:1px solid var(--line);padding-top:16px;padding-bottom:40px;color:var(--muted);font-size:14px}
ul{padding-left:20px}li{margin-bottom:6px}