:root{
  --bg:#f5f7fa;
  --card:#ffffff;
  --text:#0f2f4a;
  --muted:#5f7285;
  --accent:#1e6fae;
  --accent-soft:#e9f2fb;
  --border:rgba(15,47,74,.12);
  --shadow:0 12px 30px rgba(15,47,74,.08);
  --radius:18px;
}
*{box-sizing:border-box}
html{scroll-behavior:smooth}
body{margin:0;font-family:Inter,system-ui,Segoe UI,Roboto,Arial,sans-serif;background:var(--bg);color:var(--text);line-height:1.65}
a{color:inherit;text-decoration:none}
img{max-width:100%;display:block}
.kb-shell{max-width:1320px;margin:0 auto;padding:0 24px}
.kb-topbar{position:sticky;top:0;z-index:30;background:rgba(255,255,255,.95);backdrop-filter:blur(10px);border-bottom:1px solid var(--border)}
.kb-topbar-inner{display:flex;align-items:center;justify-content:space-between;gap:20px;min-height:78px}
.kb-brand{display:flex;align-items:center;gap:12px;min-width:0}
.kb-brand img{width:48px;height:48px;object-fit:contain}
.kb-brand strong{display:block;font-size:20px;line-height:1.1}
.kb-brand span{display:block;color:var(--muted);font-size:13px;margin-top:2px}
.kb-nav{display:flex;flex-wrap:wrap;justify-content:flex-end;gap:18px;font-weight:700;color:var(--muted)}
.kb-nav a{padding:6px 0;border-bottom:2px solid transparent}
.kb-nav a:hover,.kb-nav a.active{color:var(--text);border-bottom-color:var(--accent)}
.knowledge-home,.article-layout{padding-top:26px;padding-bottom:36px}
.article-layout{display:grid;grid-template-columns:minmax(0,1fr) 330px;gap:22px;align-items:start}
.hero-card,.side-card,.knowledge-card,.cluster-section,.toolbar,.anchor-strip,.cta-panel,.note,.toc-card{background:var(--card);border:1px solid var(--border);border-radius:var(--radius);box-shadow:var(--shadow)}
.hero-card{display:grid;grid-template-columns:minmax(0,1.45fr) minmax(280px,.85fr);gap:22px;padding:28px}
.hero-home,.hero-article{margin-bottom:20px}
.hero-copy h1{font-size:42px;line-height:1.05;margin:0 0 14px}
.lead{font-size:18px;color:var(--muted);margin:0 0 16px}
.chip,.small-chip{display:inline-flex;align-items:center;gap:8px;font-weight:800;font-size:12px;border-radius:999px;padding:7px 12px;background:var(--accent-soft);color:var(--accent)}
.small-chip{padding:5px 10px;font-size:11px}
.hero-actions,.cta-actions{display:flex;flex-wrap:wrap;gap:12px;margin-top:16px}
.btn{display:inline-flex;align-items:center;justify-content:center;padding:12px 16px;border-radius:12px;border:1px solid var(--border);background:#fff;font-weight:800;cursor:pointer;transition:transform .12s ease,border-color .12s ease,box-shadow .12s ease}
.btn:hover{transform:translateY(-1px);border-color:rgba(30,111,174,.35);box-shadow:0 10px 22px rgba(30,111,174,.12)}
.btn-primary{background:var(--accent);border-color:var(--accent);color:#fff}
.hero-aside h2,.side-card h2,.anchor-strip h2,.cluster-head h2,.article-main h2,.cta-panel h2,.toc-card h2{margin:0 0 12px;font-size:24px;line-height:1.2}
.hero-aside,.side-card,.toc-card{padding:22px}
.check-list,.bullet-list{margin:0;padding-left:18px}
.check-list li,.bullet-list li{margin:0 0 10px}
.toolbar{display:grid;grid-template-columns:minmax(320px,.8fr) minmax(0,1fr);gap:20px;padding:22px;margin:0 0 20px}
.search-box span{display:block;font-weight:800;margin-bottom:8px}
.search-box input{width:100%;padding:14px 16px;border:1px solid var(--border);border-radius:14px;font:inherit}
.toolbar-note,.muted-paragraph{color:var(--muted)}
.anchor-strip{padding:24px;margin-bottom:20px}
.anchor-grid{display:grid;grid-template-columns:repeat(2,minmax(0,1fr));gap:14px}
.anchor-link{display:block;border:1px solid var(--border);border-radius:14px;padding:14px 16px;font-weight:800;background:#fbfdff}
.anchor-link:hover{border-color:rgba(30,111,174,.35);background:var(--accent-soft)}
.cluster-section{padding:24px;margin-bottom:18px}
.cluster-head{display:flex;align-items:flex-start;justify-content:space-between;gap:18px;padding-bottom:18px;border-bottom:1px solid var(--border);margin-bottom:18px}
.cluster-head p{color:var(--muted);margin:10px 0 0}
.knowledge-grid{display:grid;grid-template-columns:repeat(3,minmax(0,1fr));gap:16px}
.knowledge-card{padding:18px}
.knowledge-card-top{min-height:20px;margin-bottom:6px}
.knowledge-card h3{font-size:18px;line-height:1.3;margin:0 0 10px}
.knowledge-card p{color:var(--muted);margin:0}
.breadcrumbs{display:flex;flex-wrap:wrap;align-items:center;gap:8px;color:var(--muted);font-size:14px;margin-bottom:16px}
.crumb-sep{opacity:.55}
.article-main,.article-side{display:grid;gap:18px}
.article-main > section:not(.hero-card){background:#fff;border:1px solid var(--border);border-radius:var(--radius);padding:24px;box-shadow:var(--shadow)}
.article-main p{margin:0 0 14px}
.article-main p:last-child{margin-bottom:0}
.strong-note{background:#f8fbff;color:#37546f;padding:16px 18px}
.toc-card .toc-list{margin:0;padding-left:18px;display:grid;grid-template-columns:repeat(2,minmax(0,1fr));gap:8px 20px}
.toc-card a{font-weight:700;color:var(--accent)}
.formula-grid{display:grid;grid-template-columns:repeat(2,minmax(0,1fr));gap:14px;margin-top:14px}
.formula-card{border:1px solid var(--border);border-radius:14px;padding:16px;background:#fbfdff}
.formula-title{font-weight:800;margin-bottom:8px}
.formula-code{font-family:ui-monospace,SFMono-Regular,Consolas,monospace;background:#0f2f4a;color:#fff;border-radius:12px;padding:10px 12px;font-size:15px;margin-bottom:10px;overflow:auto}
.subsection-grid{display:grid;grid-template-columns:repeat(2,minmax(0,1fr));gap:18px;margin-top:18px}
.ordered-list{padding-left:20px;margin:0}
.ordered-list li{margin-bottom:10px}
.mini-table{width:100%;border-collapse:collapse;margin-top:14px}
.mini-table th,.mini-table td{padding:10px 12px;border-bottom:1px solid var(--border);text-align:left;vertical-align:top}
.mini-table th{width:42%;background:#fbfdff}
.mini-table-symbols th{width:24%}
.faq details{border:1px solid var(--border);border-radius:12px;padding:14px 16px;background:#fbfdff;margin-bottom:12px}
.faq summary{cursor:pointer;font-weight:800}
.faq p{margin:10px 0 0;color:var(--muted)}
.link-list{list-style:none;padding:0;margin:0}
.link-list li{margin-bottom:10px}
.link-list a{font-weight:700;color:var(--accent)}
.cta-panel{display:flex;align-items:center;justify-content:space-between;gap:20px;padding:24px}
.kb-footer{border-top:1px solid var(--border);background:#fff;padding:18px 0;color:var(--muted)}
.kb-footer .kb-shell{display:flex;align-items:center;justify-content:space-between;gap:16px;flex-wrap:wrap}
@media (max-width:1100px){.article-layout{grid-template-columns:1fr}.knowledge-grid{grid-template-columns:repeat(2,minmax(0,1fr))}.hero-card,.subsection-grid,.toc-card .toc-list{grid-template-columns:1fr}}
@media (max-width:760px){.kb-shell{padding:0 16px}.kb-topbar-inner{align-items:flex-start;padding:12px 0}.hero-copy h1{font-size:32px}.knowledge-grid,.formula-grid,.anchor-grid,.toolbar,.subsection-grid,.toc-card .toc-list{grid-template-columns:1fr}.cluster-head,.cta-panel{display:grid}.hero-card,.article-main>section:not(.hero-card),.side-card,.cluster-section,.toolbar,.anchor-strip,.toc-card{padding:18px}.kb-brand strong{font-size:18px}}