:root{
  --ink:#1a1a1a; --ink-2:#4a4a4a; --ink-3:#7a7a7a;
  --line:#e6e6e6; --bg:#ffffff; --bg-2:#f7f8fa; --brand:#0b6b53; --brand-2:#0e8466;
}
*{box-sizing:border-box;}
html{-webkit-text-size-adjust:100%;}
body{
  margin:0; background:var(--bg); color:var(--ink);
  font-family:-apple-system,BlinkMacSystemFont,"PingFang SC","Hiragino Sans GB",
              "Microsoft YaHei","Source Han Sans SC",sans-serif;
  font-size:17px; line-height:1.85; letter-spacing:.01em;
}
a{color:var(--brand); text-decoration:none;}
a:hover{text-decoration:underline;}
.wrap{max-width:860px; margin:0 auto; padding:0 22px;}

/* 顶部 */
.topbar{
  border-bottom:1px solid var(--line); background:rgba(255,255,255,.92);
  backdrop-filter:saturate(180%) blur(8px); position:sticky; top:0; z-index:9;
}
.topbar .wrap{display:flex; align-items:center; justify-content:space-between; height:58px;}
.topbar .brand{font-weight:700; letter-spacing:.02em;}
.topbar .brand span{color:var(--ink-3); font-weight:400; margin-left:8px; font-size:14px;}
.topbar nav a{margin-left:18px; font-size:14px; color:var(--ink-2);}

/* 首页 hero */
.hero{padding:56px 0 40px; border-bottom:1px solid var(--line);}
.hero .kicker{color:var(--brand); font-size:14px; font-weight:600; letter-spacing:.14em;}
.hero h1{font-size:38px; line-height:1.35; margin:14px 0 10px; letter-spacing:-.01em;}
.hero .sub{font-size:19px; color:var(--ink-2); margin:0 0 6px;}
.hero .tag{color:var(--ink-3); font-size:15px; margin:0;}
.hero .actions{margin-top:26px; display:flex; gap:12px; flex-wrap:wrap;}
.btn{
  display:inline-block; padding:11px 22px; border-radius:8px;
  background:var(--brand); color:#fff; font-weight:600; font-size:15px;
}
.btn:hover{background:var(--brand-2); text-decoration:none;}
.btn.ghost{background:#fff; color:var(--ink); border:1px solid var(--line);}
.btn.ghost:hover{background:var(--bg-2);}

/* 数据速览 */
.stats{
  display:grid; grid-template-columns:repeat(4,1fr); gap:1px;
  background:var(--line); border:1px solid var(--line); border-radius:10px; overflow:hidden;
  margin:38px 0 8px;
}
.stats div{background:#fff; padding:20px 12px; text-align:center;}
.stats b{display:block; font-size:26px; color:var(--brand); letter-spacing:-.01em;}
.stats small{color:var(--ink-3); font-size:13px;}

/* 通用区块 */
section{padding:34px 0;}
h2{font-size:24px; margin:38px 0 14px; letter-spacing:-.01em;}
h3{font-size:19px; margin:26px 0 10px;}
p{margin:12px 0;}
ul,ol{padding-left:1.35em; margin:12px 0;}
li{margin:6px 0;}
hr{border:0; border-top:1px solid var(--line); margin:34px 0;}
blockquote{
  margin:22px 0; padding:14px 18px; background:var(--bg-2);
  border-left:3px solid var(--brand); border-radius:0 8px 8px 0; color:var(--ink-2);
  font-size:15.5px;
}
blockquote p{margin:4px 0;}

/* 表格 */
table{border-collapse:collapse; width:100%; margin:18px 0; font-size:15.5px; display:block; overflow-x:auto;}
th,td{border:1px solid var(--line); padding:9px 12px; text-align:left; vertical-align:top;}
th{background:var(--bg-2); font-weight:600; white-space:nowrap;}
tbody tr:nth-child(even){background:#fcfcfd;}

code{background:var(--bg-2); padding:1px 6px; border-radius:4px; font-size:14px;}
pre{
  background:#f4f6f8; border:1px solid var(--line); border-radius:8px;
  padding:16px 18px; overflow-x:auto; font-size:14.5px; line-height:1.7;
}
pre code{background:none; padding:0;}

/* 章节导航 */
.toc{display:grid; grid-template-columns:repeat(2,1fr); gap:10px; margin:20px 0 6px;}
.toc a{
  display:block; padding:14px 16px; border:1px solid var(--line); border-radius:9px;
  color:var(--ink); font-size:15.5px; line-height:1.5;
}
.toc a:hover{background:var(--bg-2); border-color:#d8d8d8; text-decoration:none;}

/* 常见问题（问答逐条可见，便于搜索引擎与 AI 读取） */
.faq{margin:18px 0 6px; counter-reset:faq;}
.faq .qa{
  border:1px solid var(--line); border-radius:9px; padding:16px 18px; margin:10px 0;
  background:#fff;
}
.faq .qa h3{
  font-size:16.5px; margin:0 0 8px; color:var(--ink); font-weight:600;
}
.faq .qa h3::before{
  counter-increment:faq; content:"Q" counter(faq);
  display:inline-block; min-width:1.9em; color:var(--brand); font-weight:700;
}
.faq .qa p{margin:0; color:var(--ink-2); font-size:15.5px; line-height:1.8;}

/* 白皮书正文页 */
.doc{padding:34px 0 10px;}
.doc .dochead{border-bottom:1px solid var(--line); padding-bottom:22px; margin-bottom:6px;}
.doc .dochead h1{font-size:32px; margin:0 0 8px; letter-spacing:-.01em;}
.doc .meta{color:var(--ink-3); font-size:14.5px;}
.docnav{
  background:var(--bg-2); border:1px solid var(--line); border-radius:10px;
  padding:16px 20px; margin:26px 0 6px; font-size:15px;
}
.docnav ol{margin:8px 0 0; padding-left:1.3em; columns:2; column-gap:28px;}
.doc nav ul{margin:8px 0 0; padding-left:1.3em;}
.doc nav li{margin:4px 0;}

footer{
  border-top:1px solid var(--line); margin-top:44px; padding:26px 0 46px;
  color:var(--ink-3); font-size:14px;
}
footer a{color:var(--ink-3);}

@media (max-width:640px){
  body{font-size:16px;}
  .hero h1{font-size:28px;}
  .stats{grid-template-columns:repeat(2,1fr);}
  .toc{grid-template-columns:1fr;}
  .docnav ol{columns:1;}
}
@media print{
  .topbar,.hero .actions,.docnav,footer{display:none;}
  body{font-size:12pt;}
  a{color:#000;}
}