:root{
  --h2-inset:16px;
  --brand:#1f8cff;
  --cyan:#16c2d6;
  --ink:#16202e;
  --muted:#5b6b7d;
  --bg:#eef3f8;
  --card:#ffffff;
  --line:#dde6ef;
  --soft:#f3f7fb;
  --header-h:62px;
}
*{box-sizing:border-box}
html{scroll-behavior:smooth}
body{
  margin:0;font-family:"PingFang SC","Microsoft YaHei",-apple-system,"Segoe UI",Roboto,Helvetica,Arial,sans-serif;
  color:var(--ink);background:var(--bg);line-height:1.75;font-size:16px;
}
a{color:var(--brand);text-decoration:none}
a:hover{text-decoration:underline}
img{max-width:100%}
h1,h2,h3,h4{line-height:1.3;color:#10202f}

/* ===== Header ===== */
.site-header{position:sticky;top:0;z-index:50;background:linear-gradient(120deg,#0b2238,#103a55);
  box-shadow:0 2px 14px rgba(8,28,48,.18)}
.header-inner{max-width:1140px;margin:0 auto;height:var(--header-h);display:flex;align-items:center;
  justify-content:space-between;padding:0 24px;gap:16px}
.brand{display:flex;align-items:center;gap:10px;color:#fff;font-weight:700;font-size:18px}
.brand:hover{text-decoration:none}
.brand-mark{width:22px;height:22px;border-radius:6px;background:conic-gradient(from 210deg,var(--cyan),var(--brand),#7b5cff);
  box-shadow:0 0 12px rgba(31,140,255,.6)}
.top-nav{display:flex;gap:22px}
.top-nav a{color:#d6e6f3;font-size:15px}
.top-nav a:hover{color:#fff;text-decoration:none}
.nav-toggle{display:none;flex-direction:column;gap:5px;background:none;border:0;cursor:pointer;padding:8px}
.nav-toggle span{width:24px;height:2px;background:#fff;border-radius:2px}
.mobile-menu{display:none;flex-direction:column;background:#0e2a40;border-top:1px solid rgba(255,255,255,.08)}
.mobile-menu a,.mobile-menu summary{padding:13px 24px;color:#d6e6f3;border-bottom:1px solid rgba(255,255,255,.06);font-size:15px}
.mobile-menu details summary{cursor:pointer;list-style:none}
.mobile-menu details summary::-webkit-details-marker{display:none}
.mobile-menu details a{padding-left:40px;font-size:14px;color:#a9c4da}
.mobile-menu a:hover{color:#fff;text-decoration:none}

/* ===== Layout ===== */
.site-main{min-height:60vh}
.doc-wrap,.list-wrap{max-width:1140px;margin:0 auto;padding:0 24px}
.page-wrap{max-width:900px;margin:0 auto;padding:0 24px}
.crumbs{padding-left:var(--h2-inset);margin:22px 0 6px}
.crumbs ol{list-style:none;display:flex;flex-wrap:wrap;gap:8px;margin:0;padding:0;font-size:13px;color:var(--muted)}
.crumbs li:not(:last-child)::after{content:"›";margin-left:8px;color:#9fb2c4}
.crumbs a{color:var(--muted)}
.doc-grid{display:grid;grid-template-columns:1fr 240px;gap:40px;align-items:start}
.doc-main{padding-left:var(--h2-inset);min-width:0}
.page-main{padding-left:48px;min-width:0}
.page-wrap > .crumbs{padding-left:48px}

/* ===== Doc title & meta ===== */
.doc-title{font-size:30px;margin:6px 0 12px}
.kw-row{display:flex;flex-wrap:wrap;gap:8px;margin-bottom:10px}
.tag-text{display:inline-block;background:var(--soft);border:1px solid var(--line);color:#3a6ea5;
  border-radius:999px;padding:3px 11px;font-size:13px}
.updated{font-size:13px;color:var(--muted);margin-bottom:14px}
.updated time{font-variant-numeric:tabular-nums}

/* ===== Body content ===== */
.doc-body{font-size:16px;color:#1d2b3a}
.doc-body h2{font-size:22px;margin:30px 0 12px;padding-bottom:8px;border-bottom:2px solid var(--line)}
.doc-body h3{font-size:18px;margin:22px 0 10px;color:#173049}
.doc-body p{margin:12px 0}
.doc-body ul.doc-list,.doc-body ol.doc-list{margin:12px 0;padding-left:22px}
.doc-body li{margin:6px 0}
.doc-body code{background:var(--soft);border:1px solid var(--line);border-radius:5px;padding:1px 6px;font-size:14px}
.doc-body hr{border:0;border-top:1px solid var(--line);margin:24px 0}

/* tables */
table.data{width:100%;border-collapse:collapse;margin:16px 0;font-size:14.5px;background:#fff;
  border:1px solid var(--line);border-radius:8px;overflow:hidden}
table.data th{background:#eaf2fb;color:#173049;text-align:left;padding:10px 12px;border-bottom:1px solid var(--line)}
table.data td{padding:9px 12px;border-bottom:1px solid #eef3f8}
table.data tr:last-child td{border-bottom:0}

/* callouts */
.callout{border-left:4px solid var(--brand);background:#f1f7ff;border-radius:0 8px 8px 0;padding:14px 16px;margin:16px 0}
.callout-summary{border-left-color:var(--cyan);background:#eefcfd}
.callout-conclusion{border-left-color:#2f9e6b;background:#eefaf2}
.callout-case{border-left-color:#e0a32e;background:#fff8ea}
.callout p{margin:6px 0}
.callout strong{color:#173049}

/* FAQ */
.faq-block{margin:34px 0 10px}
.faq-title{font-size:22px;margin-bottom:10px}
.faq-block details{border:1px solid var(--line);background:#fff;border-radius:8px;margin:8px 0;overflow:hidden}
.faq-block summary{cursor:pointer;padding:12px 16px;font-weight:600;color:#173049;list-style:none}
.faq-block summary::-webkit-details-marker{display:none}
.faq-block summary::before{content:"+";display:inline-block;width:18px;color:var(--brand);font-weight:700}
.faq-block details[open] summary::before{content:"−"}
.faq-a{padding:0 16px 14px;color:#2a3a4b}

/* related */
.related-block{margin:30px 0}
.related-title{font-size:22px;margin-bottom:10px}
.related-list{list-style:none;padding:0;margin:0}
.related-list li{background:#fff;border:1px solid var(--line);border-radius:8px;padding:12px 14px;margin:8px 0}
.related-list a{font-weight:600}
.related-reason{display:block;font-size:13px;color:var(--muted);margin-top:3px}

/* TOC */
.toc-aside{position:sticky;top:calc(var(--header-h) + 18px);max-height:calc(100vh - 100px);overflow:auto}
.toc-box{border:1px solid var(--line);background:#fff;border-radius:10px;padding:14px 16px}
.toc-h{font-size:13px;color:var(--muted);text-transform:uppercase;letter-spacing:.06em;margin-bottom:8px}
.toc-list{list-style:none;margin:0;padding:0}
.toc-list li{margin:7px 0;font-size:14px}
.toc-list a{color:#3a6ea5}

/* ===== Listings ===== */
.list-grid{display:grid;grid-template-columns:220px 1fr;gap:32px;align-items:start}
.cat-side{position:sticky;top:calc(var(--header-h) + 18px)}
.cat-side-h{font-size:13px;color:var(--muted);text-transform:uppercase;letter-spacing:.06em;margin-bottom:8px}
.category-list{list-style:none;margin:0;padding:0}
.category-list li{margin:2px 0}
.category-list a{display:block;padding:9px 12px;border-radius:8px;color:#2a3a4b;font-size:15px}
.category-list a:hover{background:var(--soft);text-decoration:none}
.category-list a.active{background:var(--brand);color:#fff}
.list-title{font-size:28px;margin:6px 0 6px}
.list-sub{color:var(--muted);margin:0 0 18px}
.item-grid{list-style:none;margin:0;padding:0;display:grid;grid-template-columns:repeat(2,1fr);gap:16px}
.item-card{background:#fff;border:1px solid var(--line);border-radius:12px;transition:.18s}
.item-card:hover{box-shadow:0 8px 24px rgba(20,60,110,.12);transform:translateY(-2px)}
.item-link{display:block;padding:16px 18px}
.item-cat{font-size:12px;color:var(--cyan);font-weight:600;margin-bottom:6px}
.item-name{font-size:17px;margin:0 0 8px;color:#143049}
.item-desc{font-size:14px;color:var(--muted);margin:0;line-height:1.6}

/* ===== Home ===== */
.home{padding-bottom:40px}
.hero{background:radial-gradient(1200px 400px at 70% -10%,rgba(22,194,214,.25),transparent),linear-gradient(120deg,#0b2238,#123b58);color:#eaf3fb;padding:54px 0 46px}
.hero-inner{max-width:1140px;margin:0 auto;padding:0 24px;display:flex;align-items:center;gap:40px}
.hero-text{flex:1}
.hero-title{font-size:40px;margin:0 0 14px;color:#fff}
.hero-sub{font-size:17px;color:#c5dcec;max-width:620px;margin:0 0 22px}
.hero-cta{display:flex;gap:14px;margin-bottom:26px}
.btn{display:inline-block;padding:11px 22px;border-radius:999px;font-weight:600;font-size:15px}
.btn-primary{background:linear-gradient(120deg,var(--cyan),var(--brand));color:#fff}
.btn-ghost{border:1px solid rgba(255,255,255,.4);color:#fff}
.btn:hover{text-decoration:none;opacity:.92}
.hero-stats{display:flex;gap:30px}
.hero-stats b{display:block;font-size:26px;color:#fff}
.hero-stats span{font-size:13px;color:#a9c4da}
.hero-art{position:relative;width:220px;height:220px;flex:none}
.hero-ring{position:absolute;inset:0;border:2px solid rgba(22,194,214,.5);border-radius:50%}
.hero-ring.r2{inset:34px;border-color:rgba(31,140,255,.5)}
.hero-dot{position:absolute;inset:84px;background:conic-gradient(from 0deg,var(--cyan),var(--brand),#7b5cff);border-radius:50%;box-shadow:0 0 30px rgba(31,140,255,.5)}
.band{max-width:1140px;margin:0 auto;padding:34px 24px 0}
.band-head{display:flex;align-items:baseline;justify-content:space-between;margin-bottom:16px}
.band-head h2{font-size:24px;margin:0}
.more{font-size:14px;color:var(--brand)}
.prod-show{list-style:none;margin:0;padding:0;display:grid;grid-template-columns:repeat(3,1fr);gap:14px}
.prod-show li a{display:flex;justify-content:space-between;align-items:center;background:#fff;border:1px solid var(--line);border-radius:12px;padding:18px;transition:.18s}
.prod-show li a:hover{box-shadow:0 8px 24px rgba(20,60,110,.12);text-decoration:none}
.ps-tag{font-weight:600;color:#143049}
.ps-arrow{font-size:13px;color:var(--cyan)}
.kw-cloud{display:flex;flex-wrap:wrap;gap:10px}
.baseline{display:grid;grid-template-columns:repeat(4,1fr);gap:14px}
.bl-card{background:#fff;border:1px solid var(--line);border-radius:12px;padding:16px}
.bl-card b{display:block;color:var(--brand);margin-bottom:6px}
.bl-card span{font-size:13.5px;color:var(--muted)}
.scene-list{list-style:none;margin:0;padding:0;display:flex;flex-wrap:wrap;gap:12px}
.scene-list li{background:#fff;border:1px solid var(--line);border-radius:999px;padding:10px 18px;color:#143049}

/* ===== Footer ===== */
.site-footer{background:#0b2238;color:#bcd2e4;margin-top:48px}
.footer-inner{max-width:1140px;margin:0 auto;padding:34px 24px;display:grid;grid-template-columns:2fr 1fr 1fr;gap:28px}
.footer-col h4{color:#fff;margin:0 0 12px;font-size:15px}
.footer-col a{display:block;color:#a9c4da;font-size:14px;margin:6px 0}
.footer-col p{font-size:14px;color:#9fbccf}
.footer-bottom{border-top:1px solid rgba(255,255,255,.08);padding:14px 24px;text-align:center;font-size:13px;color:#7e9ab0}

/* ===== Float capsule & wechat modal ===== */
.float-capsule{position:fixed;right:18px;top:50%;transform:translateY(-50%);z-index:60;display:flex;flex-direction:column;gap:12px}
.cap-btn{width:46px;height:46px;border:0;border-radius:999px;cursor:pointer;font-size:18px;color:#fff;
  background:linear-gradient(135deg,var(--cyan),var(--brand));box-shadow:0 6px 18px rgba(31,140,255,.45);font-weight:700}
.cap-btn:hover{opacity:.92}
.cap-wechat{background:linear-gradient(135deg,#27c06a,#16a85a)}
.wechat-modal{position:fixed;inset:0;background:rgba(6,18,30,.66);z-index:80;display:flex;align-items:center;justify-content:center}
.wechat-modal[hidden]{display:none}
.wechat-modal-inner{position:relative;background:#fff;border-radius:14px;padding:10px}
.wechat-modal-inner img{width:300px;height:500px;display:block;border-radius:8px;object-fit:contain}
.wechat-close{position:absolute;top:-14px;right:-14px;width:34px;height:34px;border-radius:50%;border:0;background:#fff;color:#333;font-size:20px;cursor:pointer;box-shadow:0 2px 10px rgba(0,0,0,.3)}

/* ===== Responsive ===== */
@media (max-width:860px){
  .top-nav{display:none}
  .nav-toggle{display:flex}
  .mobile-menu[hidden]{display:none}
  .mobile-menu:not([hidden]){display:flex}
  .doc-grid{grid-template-columns:1fr}
  .toc-aside{display:none}
  .doc-main{padding-left:0}
  .page-main{padding-left:0}
  .crumbs{padding-left:0}
  .page-wrap > .crumbs{padding-left:0}
  .list-grid{grid-template-columns:1fr}
  .cat-side{position:static}
  .item-grid{grid-template-columns:1fr}
  .prod-show{grid-template-columns:1fr}
  .baseline{grid-template-columns:1fr 1fr}
  .hero-inner{flex-direction:column;align-items:flex-start}
  .hero-art{display:none}
  .footer-inner{grid-template-columns:1fr}
  .wechat-modal-inner img{width:260px;height:433px}
}