:root{
  --bg:#F5F3FF;
  --soft:#ECE9FB;
  --card:#FFFFFF;
  --text:#191927;
  --muted:#67677D;
  --border:rgba(25,25,41,.09);
  --border-soft:rgba(25,25,41,.055);
  --sans:-apple-system,BlinkMacSystemFont,"SF Pro Text","Segoe UI",Roboto,sans-serif;
  --hanzi:"PingFang SC","Hiragino Sans GB","Noto Sans SC","Microsoft YaHei",sans-serif;
}
*{box-sizing:border-box}
html{scroll-behavior:smooth}
body{margin:0;background:var(--bg);color:var(--text);font-family:var(--sans);
  -webkit-font-smoothing:antialiased;text-rendering:optimizeLegibility}
a{color:inherit;text-decoration:none}
.top{position:fixed;z-index:20;inset:0 0 auto;height:44px;
  background:rgba(245,243,255,.96);backdrop-filter:blur(14px) saturate(1.3);
  border-bottom:1px solid var(--border)}
.top-in{width:min(1100px,100%);height:100%;margin:auto;padding:0 32px;
  display:flex;align-items:center;gap:9px}
.top-brand{display:inline-flex;align-items:center;gap:7px;font-size:13px;font-weight:700;
  letter-spacing:-.015em}
.top-brand img{width:28px;height:28px;object-fit:contain;transform:translateY(-.25px)}
.top-section{font-size:11.5px;color:var(--muted)}
.top-section::before{content:"/";margin-right:9px;color:rgba(25,25,41,.25)}
.top-site{margin-left:auto;font-size:11.5px;font-weight:550;color:var(--muted);
  transition:color .18s ease}
.top-site:hover{color:var(--text)}
.layout{width:min(1100px,100%);margin:auto;padding:80px 32px 92px;
  display:grid;grid-template-columns:218px minmax(0,720px);gap:68px}
.sidebar{position:sticky;top:76px;align-self:start}
.toc-title{margin:0 0 23px;font-size:13px;font-weight:700;letter-spacing:-.01em;color:var(--text)}
.toc-groups{display:grid;gap:21px}
.chapter-link{display:block;margin-inline:-8px;padding:6px 8px;border-radius:7px;
  font-size:13px;line-height:1.45;font-weight:620;color:var(--muted);
  transition:color .18s ease,background-color .18s ease}
.chapter-link:hover,.toc-group.current>.chapter-link{color:var(--text)}
.toc-group.current>.chapter-link{background:rgba(25,25,41,.055);font-weight:700}
.toc-sub{display:grid;gap:7px;margin:8px 0 0;padding-left:8px;list-style:none}
.toc-sub a{font-size:11.5px;line-height:1.45;color:var(--muted);
  transition:color .18s ease}
.toc-sub a:hover,.toc-sub a.active{color:var(--text)}
.toc-sub a.active{font-weight:620}
.content{min-width:0}
.doc-section{padding-top:0}
.doc-section[hidden]{display:none}
.doc-section.active{animation:sectionIn .18s ease}
@keyframes sectionIn{from{opacity:0}to{opacity:1}}
h2{margin:0 0 15px;font-size:20px;line-height:1.3;font-weight:700;letter-spacing:-.015em}
h3{margin:26px 0 10px;font-size:15px;line-height:1.45;font-weight:700}
p{margin:0;font-size:15px;line-height:1.75}
p+p{margin-top:13px}
strong{font-weight:680}
.note{margin:22px 0;padding:17px 19px;background:var(--soft);
  border:1px solid var(--border-soft)}
.note b{display:block;margin-bottom:5px;font-size:13px}
.note p{font-size:13.5px;line-height:1.65;color:var(--muted)}
.facts{display:grid;grid-template-columns:repeat(3,minmax(0,1fr));gap:1px;
  margin:22px 0;background:var(--border);border:1px solid var(--border)}
.facts div{padding:16px;background:var(--card)}
.facts b{display:block;margin-bottom:6px;font-size:13px}
.facts span{display:block;font-size:12px;line-height:1.5;color:var(--muted)}
.rows{margin:21px 0;border-top:1px solid var(--border)}
.row{display:grid;grid-template-columns:105px minmax(0,1fr);gap:20px;
  padding:14px 0;border-bottom:1px solid var(--border-soft)}
.row b{font-size:13px;line-height:1.5}
.row span,.row p{font-size:13.5px;line-height:1.6;color:var(--muted)}
.timeline .row{grid-template-columns:70px minmax(0,1fr) 126px}
.timeline .row>span:last-child{text-align:right;font-size:12px}
.table-wrap{margin:22px 0;overflow:auto;border:1px solid var(--border)}
table{width:100%;border-collapse:collapse;background:var(--card);font-size:13px}
th,td{padding:12px 14px;text-align:left;border-bottom:1px solid var(--border-soft)}
th{font-size:11px;font-weight:680;color:var(--muted);background:var(--soft)}
tr:last-child td{border-bottom:0}
td:first-child{font-variant-numeric:tabular-nums;font-weight:620}
.modes{display:grid;grid-template-columns:repeat(2,minmax(0,1fr));margin:22px 0;
  border:1px solid var(--border)}
.mode{padding:18px;background:var(--card)}
.mode+.mode{border-left:1px solid var(--border)}
.mode b{display:block;margin-bottom:7px;font-size:15px}
.mode p{font-size:13px;line-height:1.6;color:var(--muted)}
.route{display:grid;grid-template-columns:repeat(7,minmax(0,1fr));gap:5px;margin:23px 0 9px}
.route span{display:grid;place-items:center;aspect-ratio:1;border:1px solid var(--border);
  background:var(--card);font-size:13px;font-weight:680}
.route span:last-child{background:var(--text);border-color:var(--text);color:#fff}
.route-cap{display:flex;justify-content:space-between;gap:20px;font-size:11.5px;color:var(--muted)}
.hanzi{display:grid;grid-template-columns:74px minmax(0,1fr);gap:21px;
  align-items:center;margin:22px 0;padding:18px;border:1px solid var(--border)}
.hanzi>span{font:400 54px/1 var(--hanzi);text-align:center}
.hanzi p{font-size:13.5px;color:var(--muted)}
.flow{margin:21px 0;border-top:1px solid var(--border)}
.flow .row{grid-template-columns:24px 134px minmax(0,1fr)}
.flow i{display:grid;place-items:center;width:22px;height:22px;border-radius:50%;
  background:var(--text);color:#fff;font-size:10px;font-style:normal;font-weight:700}
.scope{display:grid;grid-template-columns:repeat(2,minmax(0,1fr));gap:1px;
  margin-top:22px;background:var(--border);border:1px solid var(--border)}
.scope div{padding:18px;background:var(--card)}
.scope b{display:block;margin-bottom:7px;font-size:13px}
.scope p{font-size:13px;line-height:1.6;color:var(--muted)}
.section-nav{display:grid;grid-template-columns:1fr 1fr;align-items:center;
  margin-top:30px}
.section-nav button{width:max-content;min-width:92px;padding:9px 13px;
  border:1px solid var(--border);border-radius:9px;background:var(--card);
  font:620 12px/1 var(--sans);color:var(--text);cursor:pointer;
  transition:background-color .18s ease,border-color .18s ease,transform .16s ease}
.section-nav button:last-child{justify-self:end}
.section-nav button:last-child{background:var(--text);border-color:var(--text);color:#fff}
.section-nav button:hover:not(:disabled){background:var(--soft)}
.section-nav button:last-child:hover:not(:disabled){background:#2B2B33}
.section-nav button:active:not(:disabled){transform:scale(.98)}
.section-nav button:disabled{visibility:hidden}
@media(max-width:820px){
  .top-in{padding-inline:20px}
  .layout{grid-template-columns:1fr;padding:72px 20px 72px;gap:38px}
  .sidebar{position:static;padding:17px 18px;background:var(--soft);border:1px solid var(--border)}
  .toc-title{margin-bottom:19px}
  .toc-groups{grid-template-columns:repeat(3,minmax(0,1fr));gap:20px}
}
@media(max-width:600px){
  .toc-groups{grid-template-columns:1fr;gap:19px}
  .facts,.modes,.scope{grid-template-columns:1fr}
  .facts div+div,.mode+.mode,.scope div+div{border-left:0;border-top:1px solid var(--border)}
  .timeline .row,.row{grid-template-columns:1fr;gap:4px}
  .timeline .row>span:last-child{text-align:left}
  .flow .row{grid-template-columns:24px minmax(0,1fr);gap:10px}
  .flow .row p{grid-column:2}
}
@media(prefers-reduced-motion:reduce){
  html{scroll-behavior:auto}
  .doc-section.active{animation:none}
}