:root{--bg:#f4f7fb;--paper:#fff;--ink:#0b1833;--muted:#5c6b80;--line:#d5e1ef;--green:#0055cb;--sans:Inter,-apple-system,BlinkMacSystemFont,"Segoe UI","PingFang SC","Microsoft YaHei",sans-serif}
*{box-sizing:border-box}
html{scroll-padding-top:24px}
body{margin:0;background:var(--bg);color:var(--ink);font:16px/1.75 var(--sans)}
a{color:var(--green)}
a:focus-visible,button:focus-visible,summary:focus-visible{outline:3px solid var(--green);outline-offset:3px}
.wrap{max-width:760px;margin:auto;padding:28px 22px 80px}
header{display:flex;align-items:center;justify-content:space-between;gap:16px;padding-bottom:22px;border-bottom:1px solid var(--line)}
.brand img{height:32px;width:auto;display:block}
.back{font-size:14px;white-space:nowrap}
.kicker{margin:28px 0 0;font-size:13px;letter-spacing:.04em;color:var(--green)}
h1{font-size:34px;letter-spacing:-.04em;line-height:1.25;margin:8px 0}
.en{margin:0;color:var(--muted);font-size:14px}
.lede{font-size:18px;line-height:1.6;margin:18px 0 8px}
h2{font-size:20px;margin:32px 0 8px;letter-spacing:-.02em}
h3{font-size:16px;margin:22px 0 6px;letter-spacing:-.02em}
p,li{font-size:15px}
ul{padding-left:1.2em}
li+li{margin-top:6px}
details{margin-top:28px;border:1px solid var(--line);border-radius:12px;background:var(--paper);padding:12px 16px}
summary{cursor:pointer;font-weight:600}
details p:last-child{margin-bottom:0}
.siblings{display:flex;flex-wrap:wrap;gap:8px;margin-top:28px}
.siblings a{display:inline-flex;align-items:center;gap:8px;padding:8px 12px;border:1px solid var(--line);border-radius:999px;background:var(--paper);color:var(--ink);text-decoration:none;font-size:13px}
.siblings a:hover,.siblings a:focus-visible{border-color:var(--green);color:var(--green)}
.siblings a[aria-current="page"]{border-color:var(--green);color:var(--green);background:#eef4fc}
footer{margin-top:40px;padding-top:18px;border-top:1px solid var(--line);color:var(--muted);font-size:13px;display:flex;flex-wrap:wrap;gap:14px}
footer button{background:none;border:0;padding:0;color:var(--green);font:inherit;cursor:pointer}
pre.eq{margin:8px 0 0;padding:14px 16px;background:var(--paper);border:1px solid var(--line);border-radius:12px;font:14px/1.75 ui-monospace,SFMono-Regular,Menlo,Consolas,monospace;white-space:pre-wrap}
@media (max-width:640px){h1{font-size:28px}.lede{font-size:16px}}