:root{
  --bg:#071018; --panel:#0c1722; --panel2:#0f1d2a; --text:#eaf2f8; --muted:#93a8b9;
  --line:#1f3444; --cyan:#5ee7f2; --blue:#6ca7ff; --green:#83e9a7; --amber:#ffc86b;
  --red:#ff8a8a; --violet:#b39cff; --shadow:0 18px 60px rgba(0,0,0,.28);
  --max:1180px;
}
*{box-sizing:border-box}
html{scroll-behavior:smooth}
body{margin:0;background:
radial-gradient(circle at 15% 0%,rgba(62,138,191,.16),transparent 30rem),
radial-gradient(circle at 90% 5%,rgba(68,218,207,.09),transparent 24rem),
var(--bg); color:var(--text); font:16px/1.78 ui-sans-serif,-apple-system,BlinkMacSystemFont,"Segoe UI","PingFang SC","Hiragino Sans GB","Microsoft YaHei",sans-serif}
a{color:var(--cyan);text-decoration:none} a:hover{text-decoration:underline}
.progress{position:fixed;top:0;left:0;height:3px;background:linear-gradient(90deg,var(--cyan),var(--blue),var(--violet));width:0;z-index:99}
.hero{max-width:var(--max);margin:auto;padding:88px 28px 48px}
.eyebrow{display:inline-flex;gap:8px;align-items:center;border:1px solid #25516a;background:#0a2230;color:#9debf2;border-radius:999px;padding:6px 12px;font-size:13px;letter-spacing:.04em}
h1{font-size:clamp(38px,6vw,72px);line-height:1.03;margin:20px 0 16px;letter-spacing:-.035em}
.hero p.lead{max-width:930px;font-size:20px;color:#bdd0dd;margin:0}
.hero-grid{display:grid;grid-template-columns:repeat(4,1fr);gap:12px;margin-top:32px}
.metric{background:linear-gradient(180deg,rgba(19,43,59,.9),rgba(10,24,34,.95));border:1px solid var(--line);border-radius:18px;padding:17px}
.metric strong{display:block;font-size:25px;color:#fff}.metric span{font-size:13px;color:var(--muted)}
.shell{max-width:var(--max);margin:auto;padding:0 28px 90px;display:grid;grid-template-columns:260px minmax(0,1fr);gap:30px}
.toc{position:sticky;top:24px;align-self:start;border:1px solid var(--line);background:rgba(10,24,34,.85);backdrop-filter:blur(14px);border-radius:18px;padding:16px;max-height:calc(100vh - 48px);overflow:auto}
.toc .title{font-size:12px;color:#7da0b5;text-transform:uppercase;letter-spacing:.16em;margin:2px 8px 10px}
.toc a{display:block;color:#a9bdca;padding:7px 9px;border-radius:9px;font-size:14px;line-height:1.35}
.toc a:hover{background:#102535;color:white;text-decoration:none}
main{min-width:0}
section{scroll-margin-top:24px;margin-bottom:26px;background:linear-gradient(180deg,rgba(13,28,39,.93),rgba(8,20,29,.94));border:1px solid var(--line);border-radius:24px;padding:30px;box-shadow:var(--shadow)}
section.flat{background:transparent;box-shadow:none;border:0;padding:6px 2px}
h2{font-size:30px;line-height:1.2;margin:0 0 18px;letter-spacing:-.02em}
h3{font-size:21px;margin:28px 0 10px;color:#f4f8fb}
h4{font-size:17px;margin:22px 0 8px;color:#cbe1ef}
p{margin:10px 0;color:#c9d8e2}
strong{color:#fff}
.muted{color:var(--muted)}
.kicker{font-size:12px;letter-spacing:.14em;text-transform:uppercase;color:var(--cyan);font-weight:700}
.callout{border-left:3px solid var(--cyan);background:#0a2330;border-radius:0 14px 14px 0;padding:15px 18px;margin:18px 0;color:#d5e7f1}
.callout.warn{border-color:var(--amber);background:#27200f}
.callout.good{border-color:var(--green);background:#10281c}
.callout.violet{border-color:var(--violet);background:#1c1930}
.grid2{display:grid;grid-template-columns:1fr 1fr;gap:15px}
.grid3{display:grid;grid-template-columns:repeat(3,1fr);gap:15px}
.card{border:1px solid var(--line);background:#0a1822;border-radius:17px;padding:18px}
.card h3,.card h4{margin-top:0}
.badge{display:inline-block;padding:3px 9px;border-radius:999px;background:#102b3a;border:1px solid #224a60;color:#9ce7ee;font-size:12px;margin:2px 3px 2px 0}
.badge.green{background:#10291b;border-color:#28553a;color:#9be6b1}
.badge.amber{background:#2a2110;border-color:#5c4721;color:#ffd18a}
.badge.violet{background:#211b36;border-color:#47386f;color:#c8b7ff}
.code,.formula{font-family:ui-monospace,SFMono-Regular,Menlo,Consolas,"Liberation Mono",monospace;background:#06121b;border:1px solid #1a3343;border-radius:14px;padding:16px;overflow:auto;color:#c8ecf4}
.formula{text-align:center;font-size:18px;padding:20px}
.flow{display:flex;gap:9px;align-items:stretch;flex-wrap:wrap;margin:18px 0}
.node{flex:1 1 135px;min-width:125px;background:#0b1c28;border:1px solid #234354;border-radius:14px;padding:14px;text-align:center}
.node b{display:block;color:white}.node small{color:#85a0b1}
.arrow{align-self:center;color:#5c879d;font-size:24px}
table{width:100%;border-collapse:collapse;margin:15px 0 4px;font-size:14px}
.table-scroll{max-width:100%;overflow-x:auto}
main li code{overflow-wrap:anywhere}
th,td{border-bottom:1px solid #1e3341;padding:12px 10px;text-align:left;vertical-align:top}
th{color:#a8c9dc;font-size:12px;text-transform:uppercase;letter-spacing:.06em}
td{color:#cbd9e2}
tr:last-child td{border-bottom:0}
.highlight{color:var(--cyan)}
.green{color:var(--green)} .amber{color:var(--amber)} .violet{color:var(--violet)} .red{color:var(--red)}
svg{max-width:100%;height:auto}
.diagram{background:#06131c;border:1px solid #183443;border-radius:18px;padding:16px;margin:18px 0}
.quote{font-size:21px;line-height:1.55;color:#e9f5fa;margin:18px 0;padding:20px;border-radius:16px;background:linear-gradient(135deg,#0e2a39,#111d2a)}
ul,ol{padding-left:22px;color:#c8d8e2}
li{margin:7px 0}
.check li::marker{color:var(--green)}
.score{display:flex;gap:10px;align-items:center;margin:8px 0}
.bar{height:9px;flex:1;background:#132532;border-radius:20px;overflow:hidden}.bar i{display:block;height:100%;background:linear-gradient(90deg,var(--cyan),var(--blue));border-radius:20px}
.big-num{font-size:38px;font-weight:800;line-height:1;color:white}
.tagline{color:#7fa3b7;font-size:13px}
details{border:1px solid #213846;border-radius:14px;padding:12px 14px;margin:10px 0;background:#091822}
summary{cursor:pointer;font-weight:700;color:#e6f2f7}
footer{max-width:var(--max);margin:auto;padding:0 28px 60px;color:#7894a5;font-size:13px}
.topbtn{position:fixed;right:20px;bottom:20px;width:42px;height:42px;border-radius:50%;border:1px solid #315568;background:#0c2230;color:#d9f7fa;cursor:pointer}
.note-index{counter-reset:note}
.note-index h3:before{counter-increment:note;content:counter(note) ". ";color:#5edee8}
@media(max-width:920px){
 .shell{grid-template-columns:1fr}.toc{position:relative;top:auto;max-height:none}
 .hero-grid,.grid3{grid-template-columns:1fr 1fr}
}
@media(max-width:620px){
 .hero{padding:72px 18px 36px}.shell{padding:0 14px 70px}
 section{padding:22px 18px;border-radius:18px}.grid2,.grid3,.hero-grid{grid-template-columns:1fr}
 h2{font-size:25px}.hero p.lead{font-size:17px}
}
@media print{
 body{background:#fff;color:#111}.toc,.topbtn,.progress{display:none}.shell{display:block}
 section{box-shadow:none;background:#fff;color:#111;border:1px solid #ddd;break-inside:avoid}
 p,td,li{color:#222} h1,h2,h3,h4,strong{color:#000}.hero p.lead,.muted{color:#555}
}


/* Keep the note's cyan technical visual language inside Soren's shared frame. */
.sp-header{position:relative;z-index:2}
.sp-header .sp-brand,.sp-nav a{color:var(--text)}
.sp-footer{color:var(--muted)}
a:focus-visible,button:focus-visible{outline:2px solid var(--cyan);outline-offset:4px}
.hero{padding-top:clamp(48px,6vw,76px)}
.back-link{display:inline-block;margin-bottom:20px;color:var(--cyan);font-size:14px}
.note-context{max-width:930px;margin:24px 0 0;color:#b6cedc;font-size:14px}
.note-context a{font-weight:600}
.toc-links{display:block}
.toc{scrollbar-width:thin}
@media(max-width:920px){
  .shell{grid-template-columns:minmax(0,1fr);gap:18px}
  .toc{min-width:0;padding:14px 16px}
  .toc .title{margin-bottom:5px}
  .toc-links{display:flex;gap:4px 8px;overflow-x:auto;white-space:nowrap;scrollbar-width:thin}
  .toc a{flex:none}
}
@media(max-width:620px){
  .hero{padding-top:42px}
  .hero-grid{gap:10px}
  .metric{padding:14px}
  .metric strong{font-size:22px}
  .shell{padding-bottom:52px}
  .diagram{overflow-x:auto}
  .topbtn{right:14px;bottom:14px}
}
@media(prefers-reduced-motion:reduce){html{scroll-behavior:auto}}
@media print{.sp-header,.sp-footer,.back-link{display:none}}