:root{
  --canvas:#F5F6F8;
  --surface:#F5F6F7;
  --ink:#00081B;
  --ink-muted:rgba(0,8,27,.62);
  --ink-soft:rgba(0,8,27,.5);
  --accent:#40C2FA;
  --accent-ink:#0E7CB0;
  --hairline:rgba(0,8,27,.10);
  --card-shadow:#FFF -2px -2px 4px,rgba(156,160,164,.52) 2px 2px 2px;
  --header-bg:rgba(245,246,248,.92);
  --nav-hover:rgba(0,8,27,.04);
  --r-lg:32px;
  --r-md:24px;
  --r-sm:16px;
}
html[data-theme="dark"]{
  --canvas:#0B0F1A;
  --surface:#141B2B;
  --ink:#EAEEF6;
  --ink-muted:rgba(234,238,246,.66);
  --ink-soft:rgba(234,238,246,.48);
  --accent-ink:#7FD4FB;
  --hairline:rgba(234,238,246,.13);
  --card-shadow:rgba(255,255,255,.03) -1px -1px 2px,rgba(0,0,0,.55) 2px 2px 6px;
  --header-bg:rgba(11,15,26,.9);
  --nav-hover:rgba(234,238,246,.07);
}
*{box-sizing:border-box;margin:0;padding:0}
html{scroll-behavior:smooth}
body{background:var(--canvas);color:var(--ink);font-family:'Geist',system-ui,-apple-system,sans-serif;font-size:16px;line-height:1.65;-webkit-font-smoothing:antialiased}
h1,h2,h3{text-wrap:balance}
p,li{text-wrap:pretty}
a{color:var(--accent-ink);text-decoration:none}
a:hover{text-decoration:underline}
a:focus-visible,button:focus-visible{outline:2px solid var(--accent);outline-offset:2px;border-radius:4px}
#progress{position:fixed;top:0;left:0;height:2px;width:0;background:var(--accent);z-index:60}
header.site{position:sticky;top:0;z-index:50;background:var(--header-bg);backdrop-filter:blur(8px);border-bottom:1px solid var(--hairline)}
.site-inner{max-width:1280px;margin:0 auto;padding:16px 32px;display:flex;align-items:center;gap:12px}
.lockup{margin-right:auto;display:flex;align-items:baseline;gap:12px}
.book-tag{font-family:'Geist Mono',monospace;font-size:14px;color:var(--ink-muted);letter-spacing:.04em}
.header-right{display:flex;align-items:center;gap:12px}
.iconbtn{display:inline-flex;align-items:center;justify-content:center;width:38px;height:38px;border:1px solid var(--hairline);background:var(--surface);border-radius:64px;color:var(--ink);cursor:pointer}
.iconbtn:hover{background:var(--nav-hover)}
.iconbtn svg{width:18px;height:18px}
.iconbtn .sun{display:none}
html[data-theme="dark"] .iconbtn .moon{display:none}
html[data-theme="dark"] .iconbtn .sun{display:block}
#toc-toggle{display:none;border:1px solid var(--hairline);background:var(--surface);border-radius:64px;padding:8px 16px;font-family:'Geist Mono',monospace;font-size:14px;color:var(--ink);cursor:pointer}
.shell{max-width:1280px;margin:0 auto;display:grid;grid-template-columns:336px minmax(0,1fr);gap:64px;padding:48px 32px 96px}
.shell.toc-hidden{grid-template-columns:minmax(0,1fr)}
.shell.toc-hidden aside.toc{display:none}
aside.toc{position:sticky;top:88px;align-self:start;height:fit-content;max-height:calc(100vh - 112px);overflow-y:auto;padding-right:6px;scrollbar-width:thin;scrollbar-color:var(--hairline) transparent}
nav.chapters h3{font-family:'Geist Mono',monospace;font-size:11px;letter-spacing:.14em;text-transform:uppercase;color:var(--ink-soft);margin:0 0 10px 14px;font-weight:500}
nav.chapters h3.section-gap{margin-top:28px;padding-top:24px;border-top:1px solid var(--hairline)}
nav.chapters ol{list-style:none}
nav.chapters li{margin-bottom:2px}
nav.chapters a,nav.chapters .soon{position:relative;display:flex;gap:12px;align-items:baseline;padding:9px 14px;border-radius:var(--r-sm);font-size:15.5px;color:var(--ink-muted);line-height:1.45}
nav.chapters a:hover{text-decoration:none;background:var(--nav-hover);color:var(--ink)}
nav.chapters a.active{background:var(--nav-hover);color:var(--ink);font-weight:500}
nav.chapters a.active::before{content:"";position:absolute;left:0;top:50%;transform:translateY(-50%);width:3px;height:18px;border-radius:3px;background:var(--accent)}
nav.chapters .num{font-family:'Geist Mono',monospace;font-size:13px;color:var(--ink-soft);min-width:22px;flex:none}
nav.chapters .soon{color:var(--ink-soft);cursor:default}
nav.chapters .pill{margin-left:auto;font-family:'Geist Mono',monospace;font-size:12px;border:1px solid var(--hairline);border-radius:64px;padding:2px 10px}
article{max-width:760px}
.chapter-eyebrow{font-family:'Geist Mono',monospace;font-size:14px;letter-spacing:.1em;text-transform:uppercase;color:var(--accent-ink)}
article h1{font-size:48px;font-weight:500;line-height:1.08;letter-spacing:-.02em;margin:16px 0}
.standfirst{font-size:20px;line-height:1.6;color:var(--ink-muted);margin-bottom:24px}
.byline{font-family:'Geist Mono',monospace;font-size:14px;color:var(--ink-muted);margin-bottom:56px;display:flex;gap:16px;flex-wrap:wrap;padding-bottom:24px;border-bottom:1px solid var(--hairline)}
article h2{font-size:32px;font-weight:500;line-height:1.2;letter-spacing:-.01em;margin:72px 0 20px}
article h3{font-size:23px;font-weight:500;line-height:1.3;margin:42px 0 14px}
article p{font-size:18px;line-height:1.72;margin-bottom:24px}
article p.lede{font-size:20px;line-height:1.65}
article code{font-family:'Geist Mono',monospace;font-size:.88em;background:var(--nav-hover);border-radius:6px;padding:2px 6px}
article ul.body,article ol.body{margin:0 0 28px 24px}
article ul.body li,article ol.body li{font-size:18px;line-height:1.65;margin-bottom:10px;padding-left:5px}
.callout{border-left:3px solid var(--accent);padding:8px 0 8px 28px;margin:40px 0}
.callout p{font-size:20px;line-height:1.6;margin:0;font-weight:500}
.fig,.tablewrap,.recap{background:var(--surface);border-radius:var(--r-lg);box-shadow:var(--card-shadow);padding:32px;margin:48px 0}
.panel-eyebrow{font-family:'Geist Mono',monospace;font-size:12px;letter-spacing:.12em;text-transform:uppercase;color:var(--ink-muted);margin-bottom:20px}
.fig .mermaid{display:flex;justify-content:center;font-family:'Geist',sans-serif!important;overflow-x:auto}
.caption{font-size:14px;color:var(--ink-muted);margin-top:18px;line-height:1.5}
.tablewrap{border-radius:var(--r-md);overflow-x:auto}
table{border-collapse:collapse;width:100%;min-width:620px}
th{font-family:'Geist Mono',monospace;font-size:12px;letter-spacing:.07em;text-transform:uppercase;color:var(--ink-muted);font-weight:500;text-align:left;padding:0 16px 12px 0;border-bottom:1px solid var(--hairline)}
td{font-size:15.5px;line-height:1.5;padding:14px 16px 14px 0;border-bottom:1px solid var(--hairline);vertical-align:top}
tr:last-child td{border-bottom:none;padding-bottom:0}
td.mono{font-family:'Geist Mono',monospace;font-size:13px;color:var(--accent-ink);white-space:nowrap}
.recap{border-radius:var(--r-md)}
.recap h3{font-family:'Geist Mono',monospace;font-size:12px;letter-spacing:.12em;text-transform:uppercase;color:var(--ink-muted);margin:0 0 12px}
.recap p{font-size:16px;line-height:1.65;margin:0}
.refs{margin-top:72px;padding-top:32px;border-top:1px solid var(--hairline)}
.refs h2{font-size:24px;margin:0 0 20px}
.refs ul{list-style:none}
.refs li{font-size:15px;color:var(--ink-muted);margin-bottom:10px;padding-left:18px;position:relative;line-height:1.55}
.refs li::before{content:"·";position:absolute;left:2px;color:var(--accent-ink)}
.nextrow{display:grid;grid-template-columns:1fr 1fr;gap:16px;margin-top:64px}
.nextrow a.next{display:flex;align-items:center;background:var(--surface);border-radius:var(--r-md);box-shadow:var(--card-shadow);padding:24px 28px;color:var(--ink)}
.nextrow a.next:hover{text-decoration:none;background:var(--nav-hover)}
.nextrow .label{font-family:'Geist Mono',monospace;font-size:12px;letter-spacing:.12em;text-transform:uppercase;color:var(--ink-muted)}
.nextrow .title{font-size:18px;font-weight:500;margin-top:6px}
footer.site{border-top:1px solid var(--hairline)}
.foot-inner{max-width:1280px;margin:0 auto;padding:32px;font-family:'Geist Mono',monospace;font-size:14px;color:var(--ink-muted)}
.toc-scrim{position:fixed;inset:0;z-index:44;background:rgba(0,8,27,.4);opacity:0;pointer-events:none;transition:opacity .25s ease}
.toc-scrim.show{opacity:1;pointer-events:auto}
body.drawer-open{overflow:hidden}
@media(max-width:980px){
  .shell{grid-template-columns:1fr;gap:28px;padding:24px 20px 64px}
  aside.toc{position:fixed;top:0;left:0;z-index:45;width:min(86vw,320px);height:100dvh;max-height:none;padding:78px 16px 28px;background:var(--canvas);border-right:1px solid var(--hairline);transform:translateX(-100%);transition:transform .25s ease;overflow-y:auto}
  aside.toc.open{transform:translateX(0)}
  #toc-toggle{display:inline-block}
  #sidebar-toggle{display:none}
  article{max-width:none}
}
@media(max-width:600px){
  .site-inner{padding:12px 16px;gap:8px}
  .book-tag{font-size:12px;letter-spacing:0}
  .header-right{gap:6px}
  .iconbtn{width:38px;height:38px}
  #toc-toggle{padding:7px 12px;font-size:13px}
  .shell{padding:24px 16px 56px}
  article h1{font-size:30px}
  article h2{font-size:24px;margin-top:48px}
  article h3{font-size:19px}
  .standfirst,article p.lede{font-size:17px}
  article p,article ul.body li,article ol.body li{font-size:16px;line-height:1.65}
  .byline{margin-bottom:36px}
  .fig,.tablewrap,.recap{padding:18px;border-radius:var(--r-md);margin:32px 0}
  .callout{padding-left:20px}
  .callout p{font-size:18px}
  .nextrow{grid-template-columns:1fr;margin-top:48px}
  .foot-inner{padding:24px 16px}
}
@media(prefers-reduced-motion:reduce){html{scroll-behavior:auto}*{transition:none!important}}