:root{--bg:#fff;--fg:#1f2328;--mut:#59636e;--line:#e5e7eb;--soft:#f6f8fa;--acc:#2563eb;--accs:rgba(37,99,235,.08);--code:#0f172a;--codefg:#e2e8f0;--warn:#b45309;--warns:rgba(245,158,11,.1);--ok:#15803d;--oks:rgba(22,163,74,.08)}
@media (prefers-color-scheme:dark){:root:not([data-theme=light]){--bg:#0d1117;--fg:#e6edf3;--mut:#9198a1;--line:#30363d;--soft:#161b22;--acc:#60a5fa;--accs:rgba(96,165,250,.1);--code:#010409;--warn:#f59e0b;--ok:#4ade80}}
*{box-sizing:border-box}html{scroll-behavior:smooth;scroll-padding-top:72px}
body{margin:0;background:var(--bg);color:var(--fg);font:16px/1.8 -apple-system,BlinkMacSystemFont,"Segoe UI","PingFang SC","Hiragino Sans GB","Microsoft YaHei",sans-serif;-webkit-text-size-adjust:100%}
a{color:var(--acc);text-decoration:none}a:hover{text-decoration:underline}
header.top{position:sticky;top:0;z-index:10;display:flex;align-items:center;gap:16px;height:56px;padding:0 20px;background:color-mix(in srgb,var(--bg) 88%,transparent);backdrop-filter:blur(10px);border-bottom:1px solid var(--line)}
header.top .brand{display:flex;align-items:center;gap:8px;font-weight:700;color:var(--fg)}header.top .brand img{width:26px;height:26px;border-radius:6px}
header.top nav{margin-left:auto;display:flex;gap:18px;font-size:14px}header.top nav a{color:var(--mut)}header.top nav a:hover{color:var(--fg)}
#menu{display:none;margin-left:auto;background:none;border:1px solid var(--line);border-radius:6px;color:var(--fg);padding:4px 10px;font-size:14px}
.wrap{display:grid;grid-template-columns:240px minmax(0,1fr) 200px;gap:40px;max-width:1320px;margin:0 auto;padding:0 20px}
aside.side{position:sticky;top:56px;height:calc(100vh - 56px);overflow:auto;padding:28px 0}
aside.side a{display:block;padding:7px 12px;border-radius:6px;color:var(--mut);font-size:15px}aside.side a:hover{background:var(--soft);color:var(--fg);text-decoration:none}
aside.side a.on{background:var(--accs);color:var(--acc);font-weight:600}
aside.side .grp{margin:18px 12px 6px;font-size:12px;color:var(--mut);letter-spacing:.05em}
aside.toc{position:sticky;top:56px;height:calc(100vh - 56px);overflow:auto;padding:32px 0;font-size:13px}
aside.toc b{display:block;margin-bottom:8px;color:var(--mut);font-weight:600}aside.toc a{display:block;padding:3px 0;color:var(--mut)}aside.toc a.h3{padding-left:12px}
main{min-width:0;padding:28px 0 80px}
.crumb{font-size:13px;color:var(--mut)}.crumb a{color:var(--mut)}
h1{font-size:32px;line-height:1.3;margin:10px 0 8px}h2{font-size:24px;margin:48px 0 14px;padding-top:8px;border-top:1px solid var(--line)}h3{font-size:19px;margin:30px 0 10px}
.lead{font-size:17px;color:var(--mut)}.muted{color:var(--mut);font-size:14px}
.updated{font-size:13px;color:var(--mut)}
code{font-family:ui-monospace,SFMono-Regular,Menlo,Consolas,monospace;font-size:.88em;background:var(--soft);border:1px solid var(--line);border-radius:5px;padding:1px 5px;word-break:break-word}
.code{position:relative;margin:14px 0}.code pre{margin:0;background:var(--code);color:var(--codefg);border-radius:10px;padding:16px 18px;overflow:auto;font-size:13.5px;line-height:1.65}
.code pre code{background:none;border:0;padding:0;color:inherit;font-size:inherit;word-break:normal}
.code .copy{position:absolute;top:8px;right:8px;font-size:12px;padding:3px 10px;border-radius:6px;border:1px solid rgba(255,255,255,.2);background:rgba(255,255,255,.08);color:#e2e8f0;cursor:pointer}
table{width:100%;border-collapse:collapse;margin:14px 0;font-size:14.5px;display:block;overflow-x:auto}
th,td{border:1px solid var(--line);padding:8px 12px;text-align:left;vertical-align:top}th{background:var(--soft);white-space:nowrap}
figure{margin:18px 0}figure img{display:block;width:100%;height:auto;border:1px solid var(--line);border-radius:10px;box-shadow:0 4px 20px rgba(0,0,0,.06)}
figcaption{margin-top:8px;text-align:center;font-size:13.5px;color:var(--mut)}
.demo{display:grid;grid-template-columns:1fr 1fr;gap:16px}.demo figure{margin:8px 0}
.callout{margin:16px 0;padding:12px 16px;border-radius:8px;border-left:4px solid var(--acc);background:var(--accs);font-size:15px}
.callout strong{display:block;margin-bottom:2px}.callout.warn{border-color:var(--warn);background:var(--warns)}.callout.ok{border-color:var(--ok);background:var(--oks)}
ol.steps{counter-reset:s;list-style:none;padding:0}ol.steps>li{counter-increment:s;position:relative;padding:6px 0 6px 40px}
ol.steps>li:before{content:counter(s);position:absolute;left:0;top:8px;width:26px;height:26px;border-radius:50%;background:var(--acc);color:#fff;font-size:13px;font-weight:700;display:flex;align-items:center;justify-content:center}
.cards{display:grid;grid-template-columns:repeat(auto-fill,minmax(220px,1fr));gap:12px}
.card{display:block;padding:16px;border:1px solid var(--line);border-radius:10px;color:var(--fg)}.card:hover{border-color:var(--acc);text-decoration:none}
.card b{display:block;margin-bottom:4px}.card span{font-size:14px;color:var(--mut)}
.formula{font-size:18px;font-weight:600;text-align:center;padding:14px;border:1px dashed var(--line);border-radius:10px}
details{border:1px solid var(--line);border-radius:8px;margin:10px 0;padding:0 16px}details[open]{background:var(--soft)}
summary{cursor:pointer;padding:12px 0;font-weight:600}details p{margin:0 0 14px}
.next{margin-top:40px;padding:14px 18px;border:1px solid var(--line);border-radius:10px;font-weight:600}
.pager{display:flex;justify-content:space-between;gap:12px;margin-top:40px}.pager a{flex:1;padding:14px 16px;border:1px solid var(--line);border-radius:10px}
.pager a small{display:block;color:var(--mut)}.pager a.r{text-align:right}
footer{border-top:1px solid var(--line);padding:24px 20px;text-align:center;font-size:13px;color:var(--mut)}
@media (max-width:1100px){.wrap{grid-template-columns:220px minmax(0,1fr)}aside.toc{display:none}}
@media (max-width:760px){.wrap{display:block;padding:0 16px}header.top{padding:0 16px}header.top nav{display:none}#menu{display:block}
aside.side{display:none;position:static;height:auto;padding:8px 0;border-bottom:1px solid var(--line)}body.open aside.side{display:block}
h1{font-size:26px}h2{font-size:21px}.demo{grid-template-columns:1fr}}