:root{
  --paper:#F4F1EB;
  --paper-2:#E8EAE4;
  --ink:#171817;
  --muted:#68706C;
  --faint:#9CA39E;
  --line:rgba(23,24,23,.15);
  --line-soft:rgba(23,24,23,.08);
  --signal:#C9534D;
  --serif:ui-serif,Georgia,"Songti SC","Noto Serif SC",serif;
  --sans:"Avenir Next","Helvetica Neue","PingFang SC","Hiragino Sans GB","Microsoft YaHei",sans-serif;
  --mono:"SFMono-Regular","Roboto Mono","Menlo",monospace;
}
html{background:var(--paper)}
body{background:var(--paper);color:var(--ink);font-family:var(--sans);letter-spacing:0;line-height:1.6}
::selection{background:var(--signal);color:var(--paper)}
nav{background:rgba(244,241,235,.84);backdrop-filter:blur(18px) saturate(120%);-webkit-backdrop-filter:blur(18px) saturate(120%);border-bottom-color:transparent}
nav.scrolled{background:rgba(244,241,235,.95);border-bottom-color:var(--line-soft)}
.nav-in{width:min(1240px,calc(100% - clamp(44px,11.6vw,224px)));max-width:none;height:72px;padding:0;margin:0 auto}
.brand{display:flex;align-items:center;gap:12px;letter-spacing:0;text-transform:none;font-weight:400;color:var(--ink)}
.brand-logo{display:block;width:116px;height:auto}.brand-sep{font-family:var(--mono);font-size:11px;color:var(--faint)}.brand-name{font-size:13px;color:var(--muted)}
.brand svg{display:none}.nav-right{gap:clamp(18px,3vw,42px)}.nav-links{gap:clamp(16px,2.8vw,30px)}.nav-links a{font-family:var(--mono);font-size:10px;letter-spacing:.05em;color:var(--muted)}.nav-links a:hover,.nav-links a.on{color:var(--signal)}
.lang{border-radius:0;padding:2px;background:rgba(255,255,255,.42)}.lang button{font-family:var(--mono);font-size:9px;border-radius:0;padding:4px 9px;color:var(--muted)}.lang button.on{background:var(--ink);color:var(--paper)}
.head{padding:clamp(142px,16vw,205px) 0 clamp(56px,7vw,86px);border-bottom:1px solid var(--line-soft)}.eyebrow{font-family:var(--mono);font-size:10px;letter-spacing:.1em;color:var(--signal);margin-bottom:28px}.eyebrow::before{background:var(--signal);width:30px}
h1{font-size:clamp(48px,7vw,92px);line-height:.95;font-weight:500;letter-spacing:-.075em;max-width:10ch}body.lang-zh h1{line-height:1.12}
.lede{max-width:40ch;margin-top:30px;color:var(--muted);font-size:16px;line-height:1.75}
.cards,.faq,.report,.tldr,main{background:transparent}.cards{padding:clamp(36px,5vw,72px) 0 clamp(96px,12vw,170px)}.card-grid{grid-template-columns:repeat(3,1fr);gap:0;background:transparent;border-top:1px solid var(--ink);border-bottom:1px solid var(--line)}.card{background:transparent;min-height:290px;padding:22px 24px 30px 0;border-right:1px solid var(--line)}.card+.card{padding-left:24px}.card:last-child{border-right:0}.card .k{font-family:var(--mono);font-size:10px;letter-spacing:.1em;color:var(--signal);margin-bottom:56px}.card h3{font-size:23px;font-weight:450;letter-spacing:-.055em;line-height:1.1}.card p{margin-top:14px;font-size:14px;color:var(--muted);line-height:1.7}.card a.act{margin-top:24px;color:var(--ink);font-family:var(--mono);font-size:10px;letter-spacing:.03em;border-bottom:1px solid var(--ink);padding-bottom:6px}.card .soon{margin-top:25px;font-family:var(--mono);font-size:10px;color:var(--signal)}
.faq{padding:clamp(72px,10vw,150px) 0;background:var(--paper-2);border-top:0}.sec-head{gap:16px;margin-bottom:58px}.sec-idx{font-family:var(--mono);font-size:10px;color:var(--signal);letter-spacing:.12em}.sec-title{font-family:var(--mono);font-size:10px;color:var(--muted);letter-spacing:.12em}.qs{border-top:1px solid var(--ink)}.qs details{border-bottom:1px solid var(--line)}.qs summary{padding:22px 40px 22px 0;font-size:clamp(18px,2vw,26px);font-weight:450;letter-spacing:-.045em}.qs summary::after{right:5px;width:10px;height:10px;border-color:var(--signal)}.ans{padding:0 70px 26px 0;max-width:66ch}.ans p{font-size:15px;color:var(--muted);line-height:1.8}.ans li{font-size:14px;color:var(--muted);border-color:var(--line-soft)}.ans li::before{background:var(--signal)}.ans strong{color:var(--ink)}a.ln{border-color:var(--line)}
.report{padding:clamp(96px,12vw,170px) 0;border-top:1px solid var(--line-soft)}.two{grid-template-columns:.72fr 1.28fr;gap:clamp(36px,8vw,140px)}.two h2{font-family:var(--serif);font-size:clamp(36px,4.6vw,64px);font-weight:400;line-height:1;letter-spacing:-.065em}.two p{font-size:15px;color:var(--muted);line-height:1.8}.checklist{border-color:var(--line);margin-top:30px}.checklist div{font-size:14px;color:var(--muted);border-color:var(--line);padding:13px 0}.checklist div em{font-family:var(--mono);font-size:10px;color:var(--signal)}.mail{font-family:var(--mono);font-size:clamp(14px,1.7vw,20px);letter-spacing:0}.reply{font-size:12px;color:var(--faint)}
.tldr{padding:44px 0 58px;background:var(--ink);color:var(--paper);border:0}.tldr .k{font-family:var(--mono);font-size:10px;letter-spacing:.1em;color:var(--signal);margin-bottom:17px}.tldr p{font-family:var(--serif);font-size:clamp(20px,2.5vw,32px);line-height:1.35;letter-spacing:-.045em;max-width:34ch}.doc{grid-template-columns:200px 1fr;gap:clamp(34px,8vw,130px)}main{padding:clamp(66px,9vw,120px) 0 clamp(96px,12vw,170px)}.toc div,.toc a{font-family:var(--mono);font-size:10px;letter-spacing:.05em}.toc a{color:var(--muted)}.toc a:hover{color:var(--signal)}.body h2{font-size:clamp(21px,2.4vw,30px);font-weight:450;letter-spacing:-.045em}.body h2 i{font-family:var(--mono);font-size:10px;color:var(--signal)}.body p,.body li{color:var(--muted)}.body section+section{border-color:var(--line)}.callout{border-color:var(--signal)}
footer{padding:28px 0 34px;background:var(--ink);border:0}.foot{width:min(1240px,calc(100% - clamp(44px,11.6vw,224px)));max-width:none;padding:0;margin:0 auto}.foot-links{gap:8px 22px}.foot-links a,.foot .c{font-family:var(--mono);font-size:9px;letter-spacing:.05em;color:rgba(244,241,235,.62)}.foot-links a:hover{color:var(--signal)}
@media(max-width:860px){.nav-in,.foot{width:calc(100% - 44px)}.card-grid{grid-template-columns:1fr}.card,.card+.card{min-height:0;padding:20px 0 28px;border-right:0;border-bottom:1px solid var(--line)}.card:last-child{border-bottom:0}.doc{grid-template-columns:1fr;gap:38px}.toc{position:static}.two{grid-template-columns:1fr;gap:34px}}
@media(max-width:620px){.nav-links{display:none}.brand-logo{width:104px}.head{padding-top:125px}h1{font-size:56px}.faq{padding-top:80px}.ans{padding-right:10px}.foot{display:block}.foot-links{margin-top:20px;justify-content:flex-start}}