:root{color-scheme:light dark;--brand:#2a61d4;--ink:#061143;--text:#1f2638;--muted:#575f78;--line:#dde1ea;--bg:#fff}
*{box-sizing:border-box}
body{margin:0;background:var(--bg);color:var(--text);font:16px/1.8 -apple-system,BlinkMacSystemFont,"PingFang SC","Hiragino Sans GB","Noto Sans SC",sans-serif;-webkit-text-size-adjust:100%}
a{color:var(--brand);text-underline-offset:3px}
a:focus-visible{outline:2px solid var(--brand);outline-offset:4px}
.skip{position:fixed;left:16px;top:8px;z-index:3;padding:8px 12px;background:var(--bg);transform:translateY(-150%)}
.skip:focus{transform:none}
header{border-bottom:1px solid var(--line);background:var(--bg);position:sticky;top:0;z-index:2}
.bar{max-width:1080px;margin:auto;padding:12px 24px;display:flex;align-items:center;justify-content:space-between;gap:16px}
.bar img{width:auto;height:28px;display:block}
.lang{display:flex;align-items:center;min-height:44px;padding:4px 12px;border:1px solid var(--line);border-radius:4px;font-size:14px;color:var(--ink);text-decoration:none;white-space:nowrap}
.lang:hover{border-color:var(--brand);color:var(--brand)}
.wrap{max-width:1080px;margin:auto;padding:0 24px;display:grid;grid-template-columns:220px minmax(0,1fr);gap:48px}
nav.toc{position:sticky;top:88px;align-self:start;padding-top:32px;font-size:14px}
nav.toc p{margin:0 0 8px;color:var(--muted);font-weight:600}
nav.toc a{display:flex;align-items:center;min-height:44px;padding:4px 0 4px 12px;border-left:2px solid var(--line);color:var(--muted);text-decoration:none}
nav.toc a:hover{color:var(--brand);border-color:var(--brand)}
main{padding:40px 0 64px;min-width:0;overflow-wrap:break-word}
h1,h2,h3{color:var(--ink)}
h1{font-size:32px;line-height:1.4;margin:0 0 8px}
.meta{color:var(--muted);font-size:14px;margin:0 0 24px}
.intro{margin:0 0 8px}
section{padding-top:16px;scroll-margin-top:88px}
h2{font-size:22px;line-height:1.5;margin:24px 0 16px;padding-bottom:8px;border-bottom:1px solid var(--line)}
h3.rule{font-size:17px;line-height:1.6;margin:24px 0 8px}
p{margin:0 0 16px}
ul,ol{margin:0 0 16px;padding-left:1.4em}
li{margin:8px 0}
footer{border-top:1px solid var(--line);color:var(--muted);font-size:14px}
footer .bar{display:block;padding-top:24px;padding-bottom:24px}
@media(max-width:820px){.wrap{display:block}nav.toc{position:static;padding-top:24px}nav.toc a{display:inline-flex;border-left:0;padding:4px 16px 4px 0}main{padding-top:24px}h1{font-size:28px}}
@media(max-width:420px){.bar,.wrap{padding-left:20px;padding-right:20px}h1{font-size:26px}}
@media(prefers-color-scheme:dark){:root{--brand:#8aafff;--ink:#e8ecf5;--text:#dde1ea;--muted:#aab3ca;--line:#34405c;--bg:#0a1022}.bar img{filter:brightness(0) invert(1)}}