:root{--ink:#1d2433;--muted:#5d6577;--line:#e3e1da;--paper:#faf8f3;--accent:#b4462b;--teal:#2f8f9a}
*{box-sizing:border-box;margin:0;padding:0}
body{font-family:"PingFang SC","Microsoft YaHei","Noto Sans SC",sans-serif;color:var(--ink);background:var(--paper);line-height:1.8}
a{color:var(--teal)}
.wrap{max-width:1040px;margin:0 auto;padding:0 24px}
.top{background:#fff;border-bottom:1px solid var(--line);position:sticky;top:0;z-index:10}
.top .wrap{display:flex;justify-content:space-between;align-items:center;height:68px}
.logo{display:flex;align-items:center;gap:10px;text-decoration:none;color:var(--ink);font-weight:700;font-size:19px;letter-spacing:1px}
.logo img{height:34px;width:auto}
.logo em{font-style:normal;color:var(--accent);margin-left:2px}
.top nav{display:flex;align-items:center}
.top nav a{color:var(--muted);text-decoration:none;margin-left:26px;font-size:15px}
.top nav a:hover,.top nav a.on{color:var(--accent)}
.top nav a.btn-login{background:var(--accent);color:#fff;padding:7px 16px;border-radius:4px}
.top nav a.btn-login:hover{color:#fff;opacity:.9}
.burger{display:none;font-size:24px;cursor:pointer}
.hero{padding:88px 0 72px;border-bottom:1px solid var(--line)}
.hero h1{font-family:"Songti SC","SimSun","Noto Serif SC",serif;font-size:40px;font-weight:700;line-height:1.35}
.hero h1 em{font-style:normal;color:var(--accent)}
.hero p{margin-top:20px;color:var(--muted);max-width:620px;font-size:17px}
.hero .cta{margin-top:30px;display:flex;gap:14px;flex-wrap:wrap}
.btn{display:inline-block;padding:10px 22px;border-radius:4px;text-decoration:none;font-size:15px;border:1px solid var(--accent)}
.btn.primary{background:var(--accent);color:#fff}
.btn.ghost{color:var(--accent);background:#fff}
section{padding:60px 0;border-bottom:1px solid var(--line)}
h2{font-size:24px;margin-bottom:24px;display:flex;align-items:center;gap:12px}
h2::before{content:"";width:6px;height:24px;background:var(--accent)}
.grid{display:grid;grid-template-columns:repeat(auto-fit,minmax(260px,1fr));gap:20px}
.card{background:#fff;border:1px solid var(--line);padding:24px}
.card h3{font-size:17px;margin-bottom:8px}
.card p,.card li{color:var(--muted);font-size:15px}
.card ul{padding-left:18px;margin-top:6px}
.steps{counter-reset:s;display:grid;grid-template-columns:repeat(auto-fit,minmax(200px,1fr));gap:20px}
.steps div{background:#fff;border:1px solid var(--line);padding:22px;position:relative}
.steps div::before{counter-increment:s;content:counter(s);position:absolute;top:-14px;left:20px;background:var(--accent);color:#fff;width:28px;height:28px;border-radius:50%;text-align:center;line-height:28px;font-size:14px}
.steps h3{font-size:16px;margin:6px 0}
.steps p{color:var(--muted);font-size:14px}
.kv p{margin-bottom:8px}
.kv b{display:inline-block;width:120px;color:var(--muted);font-weight:400}
.doc{background:#fff;border:1px solid var(--line);padding:40px 44px;margin:48px auto}
.doc h1{font-size:28px;margin-bottom:6px}
.doc .meta{color:var(--muted);font-size:14px;margin-bottom:28px}
.doc h2{font-size:19px;margin:30px 0 12px}
.doc h2::before{height:18px;width:5px}
.doc p,.doc li{font-size:15px;margin-bottom:8px}
.doc ul,.doc ol{padding-left:22px;margin-bottom:10px}
.foot{padding:36px 0 20px;color:var(--muted);font-size:14px}
.foot .cols{display:grid;grid-template-columns:repeat(auto-fit,minmax(240px,1fr));gap:20px}
.foot b{color:var(--ink);display:block;margin-bottom:6px}
.foot a{color:var(--muted)}
.foot .copy{margin-top:24px;padding-top:16px;border-top:1px solid var(--line);font-size:13px;text-align:center}
@media(max-width:760px){
  .hero h1{font-size:30px}
  .burger{display:block}
  .top nav{display:none;position:absolute;top:68px;left:0;right:0;background:#fff;flex-direction:column;align-items:flex-start;padding:10px 24px;border-bottom:1px solid var(--line)}
  .top nav a{margin:8px 0}
  #navtoggle:checked ~ nav{display:flex}
  .doc{padding:26px 20px}
}