:root{
  --navy:#0f172a; --blue:#1e3a8a; --blue2:#1d4ed8; --line:#e2e8f0; --muted:#64748b;
  --bg:#f1f5f9; --card:#ffffff; --ink:#0f172a; --soft:#f8fafc;
}
*{box-sizing:border-box}
html{scroll-behavior:smooth}
body{margin:0;font-family:'Segoe UI',system-ui,-apple-system,Roboto,Arial,sans-serif;background:var(--bg);color:var(--ink);line-height:1.6}
a{color:var(--blue2);text-decoration:none}
.wrap{display:flex;max-width:1200px;margin:0 auto}
nav.side{position:sticky;top:0;align-self:flex-start;height:100vh;width:250px;flex:none;background:linear-gradient(180deg,var(--blue) 0%,var(--navy) 100%);color:#fff;padding:22px 0;overflow-y:auto}
nav.side .brand{padding:0 20px 16px;border-bottom:1px solid rgba(255,255,255,.12);margin-bottom:10px}
nav.side .brand b{font-size:15px}
nav.side .brand span{display:block;font-size:11px;color:#bfdbfe;letter-spacing:.08em;text-transform:uppercase;margin-top:2px}
nav.side a{display:block;color:#dbeafe;padding:10px 20px;font-size:13.5px;border-left:3px solid transparent}
nav.side a:hover{background:rgba(255,255,255,.08);border-left-color:#60a5fa;color:#fff}
nav.side a.active{background:rgba(255,255,255,.12);border-left-color:#60a5fa;color:#fff;font-weight:600}
nav.side .sub{padding:6px 20px 4px;font-size:10.5px;letter-spacing:.1em;text-transform:uppercase;color:#93c5fd;margin-top:8px}
main{flex:1;min-width:0;padding:34px 40px 80px}
header.hero{background:linear-gradient(135deg,var(--blue) 0%,var(--navy) 100%);color:#fff;border-radius:20px;padding:34px;margin-bottom:28px;box-shadow:0 12px 30px rgba(30,58,138,.25)}
header.hero .eyebrow{font-size:11px;letter-spacing:.15em;text-transform:uppercase;color:#bfdbfe}
header.hero h1{margin:.3em 0 .2em;font-size:26px}
header.hero p{margin:0;color:#dbeafe;max-width:64ch}
section{background:var(--card);border:1px solid var(--line);border-radius:16px;padding:26px 28px;margin-bottom:22px;scroll-margin-top:16px}
section h2{margin:0 0 4px;font-size:20px;color:var(--blue)}
section h2 .num{display:inline-flex;align-items:center;justify-content:center;width:28px;height:28px;background:var(--blue);color:#fff;border-radius:8px;font-size:14px;margin-right:10px}
section h3{font-size:15px;margin:20px 0 6px;color:var(--navy)}
p,li{font-size:14.5px;color:#334155}
.lead{color:var(--muted)}
table{width:100%;border-collapse:collapse;margin:10px 0;font-size:13.5px}
th,td{text-align:left;padding:9px 12px;border-bottom:1px solid var(--line);vertical-align:top}
th{background:var(--soft);color:var(--muted);font-size:11.5px;text-transform:uppercase;letter-spacing:.05em}
.grid{display:grid;gap:14px}
.g2{grid-template-columns:1fr 1fr}.g3{grid-template-columns:repeat(3,1fr)}
@media(max-width:820px){.g2,.g3{grid-template-columns:1fr}nav.side{display:none}main{padding:20px}}
.cardlet{border:1px solid var(--line);border-radius:12px;padding:16px;background:var(--soft)}
.cardlet b{color:var(--navy)}
.linkcard{display:block;border:1px solid var(--line);border-radius:12px;padding:18px;background:var(--soft);transition:.15s}
.linkcard:hover{border-color:var(--blue2);box-shadow:0 6px 18px rgba(30,64,175,.10);transform:translateY(-2px)}
.linkcard b{color:var(--navy);font-size:15px}
.badge{display:inline-block;padding:2px 8px;border-radius:999px;font-size:11px;font-weight:600}
.b-blue{background:#dbeafe;color:#1e40af}.b-green{background:#dcfce7;color:#166534}.b-amber{background:#fef3c7;color:#92400e}.b-violet{background:#ede9fe;color:#5b21b6}.b-slate{background:#e2e8f0;color:#334155}
.diagram{background:#fff;border:1px dashed #cbd5e1;border-radius:12px;padding:16px;margin:12px 0;overflow-x:auto}
.mermaid{display:flex;justify-content:center}
ul.clean{list-style:none;padding-left:0}ul.clean li{padding-left:22px;position:relative;margin:4px 0}
ul.clean li:before{content:"▸";position:absolute;left:4px;color:var(--blue2)}
code{background:#eef2ff;color:#3730a3;padding:1px 6px;border-radius:5px;font-size:12.5px}
footer{color:var(--muted);font-size:12.5px;text-align:center;padding:24px}
.toc-note{font-size:12px;color:var(--muted)}
.pager{display:flex;justify-content:space-between;margin-top:8px;gap:10px}
.pager a{font-size:13.5px;font-weight:600}