@font-face{font-family:"Fraunces";font-style:normal;font-weight:300 800;font-display:swap;src:url("fonts/fraunces-normal-latin.woff2") format("woff2");unicode-range:U+0000-00FF,U+0131,U+0152-0153,U+02BB-02BC,U+02C6,U+02DA,U+02DC,U+2000-206F,U+2074,U+20AC,U+2122,U+2191,U+2193,U+2212,U+2215,U+FEFF,U+FFFD}
@font-face{font-family:"Fraunces";font-style:normal;font-weight:300 800;font-display:swap;src:url("fonts/fraunces-normal-latin-ext.woff2") format("woff2");unicode-range:U+0100-02AF,U+0304,U+0308,U+0329,U+1E00-1E9F,U+1EF2-1EFF,U+2020,U+20A0-20AB,U+20AD-20C0,U+2113,U+2C60-2C7F,U+A720-A7FF}
@font-face{font-family:"Fraunces";font-style:italic;font-weight:300 800;font-display:swap;src:url("fonts/fraunces-italic-az.woff2") format("woff2");unicode-range:U+0041-005A,U+0061-007A,U+00C2,U+00CE,U+00E2,U+00EE}
@font-face{font-family:"Fraunces";font-style:italic;font-weight:300 800;font-display:swap;src:url("fonts/fraunces-italic-ro.woff2") format("woff2");unicode-range:U+0102-0103,U+0218-021B}
@font-face{font-family:"IBM Plex Sans";font-style:normal;font-weight:300 700;font-display:swap;src:url("fonts/IBMPlexSans-latin.woff2") format("woff2");unicode-range:U+0000-00FF,U+0131,U+0152-0153,U+02BB-02BC,U+02C6,U+02DA,U+02DC,U+2000-206F,U+2074,U+20AC,U+2122,U+2191,U+2193,U+2212,U+2215,U+FEFF,U+FFFD}
@font-face{font-family:"IBM Plex Sans";font-style:normal;font-weight:300 700;font-display:swap;src:url("fonts/IBMPlexSans-latin-ext.woff2") format("woff2");unicode-range:U+0100-02AF,U+0304,U+0308,U+0329,U+1E00-1E9F,U+1EF2-1EFF,U+2020,U+20A0-20AB,U+20AD-20C0,U+2113,U+2C60-2C7F,U+A720-A7FF}

:root{
  color-scheme:dark;
  --bg:#05080c;--bg-2:#0b121a;--surface:#0e1620;--surface-2:#16212e;
  --ink:#f4f0e6;--ink-2:#d9d5ca;--muted:#a9afb5;--line:#27323f;
  --book:#f5b94f;--book-ink:#1a1204;      /* the textbook */
  --scan:#86dbea;--scan-ink:#04161a;       /* what the scans show */
  --alert:#ff7a63;
  --card:rgba(6,10,15,.9);
  --serif:"Fraunces","Iowan Old Style",Georgia,serif;--sans:"IBM Plex Sans",system-ui,-apple-system,"Segoe UI",sans-serif;
  --topbar:52px;--stageh:100svh;
}
:root[data-theme="light"]{
  color-scheme:light;
  --bg:#f3eee3;--bg-2:#ebe4d4;--surface:#fbf8f1;--surface-2:#efe8d9;
  --ink:#16120d;--ink-2:#322d25;--muted:#4f4a41;--line:#cdc2ab;
  --book:#7a4300;--book-ink:#fff7e8;
  --scan:#075a70;--scan-ink:#effafc;
  --alert:#a3321f;
  --card:rgba(251,248,241,.93);
}
*{box-sizing:border-box}
[hidden]{display:none!important}
svg[hidden]{display:none}
html{-webkit-text-size-adjust:100%;scroll-behavior:smooth;scroll-padding-top:calc(var(--topbar) + 12px)}
@media (prefers-reduced-motion:reduce){html{scroll-behavior:auto}}
body{margin:0;background:var(--bg);color:var(--ink);font-family:var(--sans);font-size:17px;line-height:1.55;-webkit-font-smoothing:antialiased;overflow-x:clip}
a{color:inherit;text-decoration-color:var(--scan);text-underline-offset:.18em;text-decoration-thickness:1.5px}
a:hover{color:var(--scan)}
:focus-visible{outline:2.5px solid var(--scan);outline-offset:3px;border-radius:4px}
.skip-link{position:absolute;left:12px;top:-60px;z-index:100;background:var(--scan);color:var(--scan-ink);padding:10px 14px;border-radius:8px;font-weight:600}
.skip-link:focus{top:10px}
.num{font-variant-numeric:tabular-nums lining-nums;white-space:nowrap}
.sr-only{position:absolute;width:1px;height:1px;overflow:hidden;clip:rect(0 0 0 0);white-space:nowrap}

/* ---------- top bar */
.topbar{position:fixed;inset:0 0 auto 0;height:var(--topbar);z-index:40;display:flex;align-items:center;gap:6px;padding:0 max(14px,env(safe-area-inset-left)) 0 max(14px,env(safe-area-inset-right));
  background:linear-gradient(var(--bg),transparent);font-size:14px}
@media (max-width:759px){.topbar{background:color-mix(in srgb,var(--bg) 84%,transparent);-webkit-backdrop-filter:blur(12px);backdrop-filter:blur(12px)}}
.brand{display:flex;align-items:center;gap:9px;font-weight:600;text-decoration:none;white-space:nowrap}
.brand-mark{width:9px;height:20px;border-radius:2px;background:repeating-linear-gradient(var(--ink) 0 3px,transparent 3px 5px);opacity:.9}
.topnav{display:none;gap:2px;margin-left:14px}
.topnav a{padding:6px 9px;border-radius:999px;text-decoration:none;color:var(--ink-2)}
.topnav a:hover,.topnav a[aria-current="true"]{color:var(--ink);background:var(--surface-2)}
@media (min-width:1080px){.topnav{display:flex}}
.spacer{flex:1}
.chip{padding:5px 10px;border-radius:999px;text-decoration:none;font-weight:600;font-size:13px;border:1px solid var(--line);color:var(--ink-2)}
.chip[aria-current="page"]{background:var(--ink);color:var(--bg);border-color:var(--ink)}
.icon-btn{width:34px;height:34px;display:grid;place-items:center;border-radius:50%;border:1px solid var(--line);background:transparent;color:var(--ink);cursor:pointer}
.icon-btn:hover{background:var(--surface-2)}

/* ---------- reading rail */
.rail{position:fixed;right:10px;top:50%;transform:translateY(-50%);z-index:30;display:none;flex-direction:column;gap:2px}
@media (min-width:1180px){.rail{display:flex}}
.rail a{display:flex;align-items:center;justify-content:flex-end;gap:8px;padding:5px 4px;text-decoration:none;font-size:12.5px;color:var(--ink-2)}
.rail .dot{width:8px;height:8px;border-radius:50%;border:1.5px solid var(--muted);flex:none}
.rail a[aria-current="true"] .dot{background:var(--scan);border-color:var(--scan);box-shadow:0 0 0 4px color-mix(in srgb,var(--scan) 25%,transparent)}
.rail .rail-label{opacity:0;transform:translateX(6px);transition:opacity .2s,transform .2s;background:var(--surface);padding:2px 8px;border-radius:6px;border:1px solid var(--line)}
.rail a:hover .rail-label,.rail a:focus-visible .rail-label{opacity:1;transform:none}
.progress{position:fixed;inset:0 0 auto 0;height:2px;z-index:45;pointer-events:none}
.progress span{display:block;height:100%;background:linear-gradient(90deg,var(--scan),var(--book));transform-origin:0 50%;transform:scaleX(0)}

/* ---------- stage */
.story{position:relative}
.stage{position:sticky;top:0;height:100vh;height:100svh;width:100%;overflow:hidden;z-index:0;background:var(--bg)}
.stage canvas{position:absolute;inset:0;width:100%;height:100%;display:block}
.stage canvas,.stage .overlay{opacity:0;transition:opacity 1s ease}
.ready .stage canvas,.ready .stage .overlay{opacity:1}
.stage .overlay{position:absolute;inset:0;width:100%;height:100%;pointer-events:none;overflow:visible}
.stage .still{position:absolute;inset:0;width:100%;height:100%;object-fit:contain;object-position:68% 50%;display:none}
.no-gl .stage canvas{display:none}
.no-gl .stage .still{display:block}
.ov-tick{stroke:var(--muted);stroke-width:1}
.ov-lab{fill:var(--ink-2);font:600 11.5px var(--sans);letter-spacing:.02em}
.ov-lab.major{fill:var(--ink);font-size:12.5px}
.ov-brk{stroke:var(--muted);stroke-width:1.2;fill:none}
.ov-book{stroke:var(--book);stroke-width:1.6;stroke-dasharray:6 5;fill:none}
.ov-book-band{fill:var(--book);opacity:.16}
.ov-scan-band{fill:var(--scan);opacity:.18}
.ov-scan-iqr{fill:var(--scan);opacity:.38}
.ov-scan-med{stroke:var(--scan);stroke-width:2.2}
.ov-note{font:600 12.5px var(--sans)}
.ov-note.book{fill:var(--book)}
.ov-note.scan{fill:var(--scan)}
.ov-halo{paint-order:stroke;stroke:var(--bg);stroke-width:4px;stroke-linejoin:round}

.hud{position:absolute;right:max(26px,env(safe-area-inset-right));top:calc(var(--topbar) + 62px);z-index:2;text-align:right;width:min(330px,40vw);pointer-events:none}
@media (min-width:1180px){.hud{right:54px}}
.hud-n{font-family:var(--serif);font-weight:500;font-size:clamp(46px,5.4vw,78px);line-height:.95;letter-spacing:-.03em;font-variant-numeric:tabular-nums lining-nums;color:var(--ink);text-shadow:0 2px 30px var(--bg)}
.hud-sub{font-size:14px;color:var(--ink-2);margin:4px 0 12px;text-shadow:0 1px 12px var(--bg)}
.legend{position:absolute;right:max(26px,env(safe-area-inset-right));bottom:8px;z-index:2;font-size:12px;color:var(--ink-2);pointer-events:none}
@media (min-width:1180px){.legend{right:54px}}
.legend ul{list-style:none;margin:0;padding:0;display:flex;gap:16px;flex-wrap:wrap;justify-content:flex-end}
.legend li{display:flex;align-items:center;gap:8px}
.legend i{width:20px;height:0;border-top:2.5px solid;flex:none}
.legend i.book{border-top-style:dashed;border-color:var(--book)}
.legend i.scan{border-color:var(--scan)}
.legend i.fuzz{height:10px;border:0;border-radius:3px;background:linear-gradient(90deg,transparent,var(--ink-2))}
.viewctl{position:absolute;left:max(14px,env(safe-area-inset-left));bottom:18px;z-index:3;display:flex;gap:6px}
@media (min-width:760px){.viewctl{left:auto;right:54px;top:calc(var(--topbar) + 10px);bottom:auto}}
.viewctl .btn{padding:7px 13px;font-size:13.5px}
.viewctl .btn[aria-current="true"]{background:var(--ink);color:var(--bg);border-color:var(--ink)}
@media (max-width:759px){
  .stage{height:58svh;z-index:6}
  .stage .still{object-position:50% 40%}
  .hud{left:auto;right:12px;top:auto;bottom:8px;width:auto;text-align:right}
  .hud-n{font-size:30px}
  .hud-sub{font-size:12px;margin:0}
  .legend{display:none}
  .viewctl{bottom:10px}
}

/* ---------- steps */
.steps{position:relative;z-index:3;margin:-100vh 0 0;margin-top:-100svh;padding:0;list-style:none;pointer-events:none}
.step{min-height:105vh;min-height:105svh;display:flex;align-items:center;padding:0 max(22px,6vw)}
.step-card{pointer-events:auto;width:min(450px,calc(50vw - 6vw - 12px));background:var(--card);border:1px solid var(--line);border-radius:16px;padding:22px 24px 20px;box-shadow:0 18px 60px rgba(0,0,0,.28)}
@media (min-width:760px){.step-card{-webkit-backdrop-filter:blur(12px);backdrop-filter:blur(12px)}}
.step-card h2{font-family:var(--serif);font-weight:560;font-size:clamp(23px,2.5vw,29px);line-height:1.14;letter-spacing:-.012em;margin:0 0 10px;text-wrap:balance}
.step-card p{margin:0 0 10px;color:var(--ink-2)}
.step-card p:last-child{margin-bottom:0}
.step-card strong{color:var(--ink);font-weight:600}
.kicker{font-size:12.5px;letter-spacing:.09em;text-transform:uppercase;color:var(--scan);font-weight:600;margin:0 0 10px}
.big{font-family:var(--serif);font-size:clamp(40px,5.2vw,58px);line-height:1;letter-spacing:-.025em;font-weight:520;color:var(--ink);font-variant-numeric:lining-nums;display:block;margin:2px 0 8px}
.big small{display:block;white-space:normal;font-size:14px;line-height:1.35;letter-spacing:0;color:var(--muted);font-family:var(--sans);font-weight:500;margin-top:6px}
.pair{display:grid;grid-template-columns:1fr 1fr;gap:10px;margin:2px 0 12px}
.pair div{border-top:3px solid var(--line);padding-top:6px}
.pair .b{border-color:var(--book)}.pair .s{border-color:var(--scan)}
.pair .v{font-family:var(--serif);font-size:30px;line-height:1.05;letter-spacing:-.02em;display:block}
.pair .b .v{color:var(--book)}.pair .s .v{color:var(--scan)}
.pair small{display:block;font-size:12.5px;line-height:1.35;color:var(--muted);margin-top:3px}
.anchor{opacity:0;margin-left:.3em;text-decoration:none;color:var(--muted);font-family:var(--sans);font-size:.6em;vertical-align:middle}
h2:hover .anchor,.anchor:focus-visible{opacity:1}
@media (hover:none){.anchor{opacity:.7}}
@media (max-width:759px){
  .steps{margin-top:-58svh}
  .step{align-items:flex-start;padding:0 12px;min-height:80svh}
  .step:first-child{min-height:100svh}
  .step-card{padding:15px 16px 14px;border-radius:14px;margin-top:calc(58svh + 14px)}
  .step-card h2{font-size:21px}
  body{font-size:16px}
}

/* ---------- hero */
.hero{min-height:100vh;min-height:100svh;align-items:center}
.hero-card{pointer-events:auto;width:min(500px,calc(50vw - 6vw - 20px));padding-top:var(--topbar)}
.hero h1{font-family:var(--serif);font-weight:540;font-size:clamp(34px,4.9vw,64px);line-height:1.03;letter-spacing:-.028em;margin:0 0 18px;text-wrap:balance;text-shadow:0 2px 40px var(--bg)}
.hero h1 em{font-style:italic;font-weight:480;color:var(--book)}
.deck{font-size:clamp(17px,1.5vw,20px);line-height:1.5;color:var(--ink-2);margin:0 0 20px;max-width:34em;text-shadow:0 1px 20px var(--bg)}
.deck strong{color:var(--ink)}
.hero-actions{display:flex;flex-wrap:wrap;gap:10px;align-items:center}
.btn{display:inline-flex;align-items:center;gap:8px;padding:11px 18px;border-radius:999px;border:1px solid var(--line);background:var(--surface);color:var(--ink);font:600 15px var(--sans);text-decoration:none;cursor:pointer;min-height:44px}
.btn:hover{background:var(--surface-2);color:var(--ink)}
.btn.primary{background:var(--scan);color:var(--scan-ink);border-color:var(--scan)}
.btn.primary:hover{filter:brightness(1.08);color:var(--scan-ink)}
.scroll-cue{font-size:13.5px;color:var(--muted);display:flex;align-items:center;gap:8px}
.scroll-cue::before{content:"";width:1.5px;height:26px;background:linear-gradient(var(--scan),transparent);animation:cue 1.8s ease-in-out infinite}
@keyframes cue{0%,100%{transform:scaleY(.4);transform-origin:top}50%{transform:scaleY(1);transform-origin:top}}
@media (prefers-reduced-motion:reduce){.scroll-cue::before{animation:none}}
@media (max-width:759px){
  .hero{align-items:flex-start}
  .hero-card{width:100%;padding-top:0;margin-top:calc(58svh + 10px);background:var(--card);border:1px solid var(--line);border-radius:14px;padding:16px}
  .step-card{width:100%}
  .hero h1{font-size:clamp(26px,7.4vw,34px);margin-bottom:10px}
  .deck{font-size:15.5px;margin-bottom:14px}
}

/* ---------- controls inside steps */
.seg{display:flex;flex-wrap:wrap;gap:6px;margin:10px 0 2px}
.seg button{font:600 14px var(--sans);padding:8px 14px;border-radius:999px;border:1px solid var(--line);background:var(--surface);color:var(--ink);cursor:pointer;min-height:44px}
.seg button[aria-pressed="true"],.seg button[aria-current="true"]{background:var(--ink);color:var(--bg);border-color:var(--ink)}
.seg-label{font-size:13px;font-weight:600;color:var(--ink);margin:12px 0 0}
.read{margin:12px 0 0;padding:12px 14px;border-radius:12px;background:var(--surface);border:1px solid var(--line);font-size:15px}
.read b{font-weight:600;color:var(--ink)}
.read .row{display:flex;justify-content:space-between;gap:10px;padding:5px 0;border-top:1px solid var(--line)}
.read .row:first-child{border-top:0}
.read .row span:last-child{font-variant-numeric:tabular-nums;text-align:right;color:var(--scan);font-weight:600}
.note-s{font-size:13px;color:var(--muted);margin-top:8px}

/* ---------- ledger */
.after{position:relative;z-index:5;background:var(--bg);border-top:1px solid var(--line)}
.prose{max-width:760px;margin:0 auto;padding:64px max(22px,5vw) 40px}
.prose h2{font-family:var(--serif);font-weight:560;font-size:clamp(26px,3vw,36px);line-height:1.12;letter-spacing:-.015em;margin:2.2em 0 .5em;text-wrap:balance}
.prose h2:first-child{margin-top:0}
.prose h3{font-size:17px;margin:1.6em 0 .3em}
.prose p,.prose li{color:var(--ink-2)}
.prose strong{color:var(--ink)}
.tablewrap{overflow-x:auto;margin:16px 0;border:1px solid var(--line);border-radius:12px}
table{border-collapse:collapse;width:100%;font-size:14.5px}
caption{text-align:left;padding:12px 14px;font-weight:600;color:var(--ink)}
th,td{padding:9px 12px;border-top:1px solid var(--line);text-align:left;vertical-align:top}
thead th{border-top:0;color:var(--muted);font-weight:600;font-size:12.5px;letter-spacing:.04em}
td.n,th.n{text-align:right;font-variant-numeric:tabular-nums}
tr.fail td:first-child{box-shadow:inset 3px 0 var(--alert)}
tr.hold td:first-child{box-shadow:inset 3px 0 var(--scan)}
.sources{padding-left:1.1em}
.sources li{margin:.4em 0;font-size:14.5px}
.fig{margin:22px 0}
.fig img{width:100%;height:auto;border-radius:10px;border:1px solid var(--line)}
.fig figcaption{font-size:13.5px;color:var(--muted);margin-top:6px}
.site-footer{display:flex;flex-wrap:wrap;gap:8px 22px;padding:26px max(22px,5vw) 60px;max-width:760px;margin:0 auto;font-size:14px;color:var(--muted)}
.back-top{position:fixed;right:max(14px,env(safe-area-inset-right));bottom:max(14px,env(safe-area-inset-bottom));z-index:35;display:flex;align-items:center;gap:6px;min-width:44px;min-height:44px;padding:0 14px;border-radius:999px;border:1px solid var(--line);background:var(--surface);color:var(--ink);font:600 13px var(--sans);cursor:pointer}

/* ---------- reader's own landmarks */
.you{pointer-events:auto;width:min(480px,100%);background:var(--card);border:1px solid var(--line);border-radius:18px;padding:22px;box-shadow:0 18px 60px rgba(0,0,0,.28)}
.you h2{font-family:var(--serif);font-weight:560;font-size:clamp(24px,2.6vw,31px);line-height:1.12;margin:0 0 8px}
.share{display:flex;align-items:center;gap:10px;flex-wrap:wrap;margin-top:12px}
.share-label{font-size:13px;color:var(--muted)}
.share-row{display:flex;gap:8px}
.sbtn{width:40px;height:40px;display:grid;place-items:center;border-radius:50%;border:1px solid var(--line);background:transparent;color:var(--ink);cursor:pointer;text-decoration:none}
@media (pointer:coarse){.sbtn{width:44px;height:44px}}
.sbtn:hover{border-color:var(--scan);color:var(--scan)}
.share-msg{font-size:13px;color:var(--muted);min-height:1.2em;margin:6px 0 0}
.btn.clear{background:transparent}

.loading{position:absolute;left:50%;top:50%;transform:translate(-50%,-50%);color:var(--muted);font-size:14px}
.ready .loading{display:none}

/* ---------- slice readout, plane, ladder */
.slice{margin-top:12px;padding:12px 14px;border-radius:12px;background:var(--surface);border:1px solid var(--line)}
.slice-h{font-weight:600;margin:0 0 8px;color:var(--ink)}
.slice-list{list-style:none;margin:0;padding:0;display:grid;gap:6px}
.slice-list li{display:grid;grid-template-columns:10px minmax(0,1fr) minmax(48px,90px) 38px;align-items:center;gap:8px;font-size:14px;color:var(--ink-2)}
.slice-list i{width:10px;height:10px;border-radius:50%}
.slice-list b{display:block;height:7px;border-radius:4px;background:linear-gradient(90deg,var(--scan) var(--w),var(--line) var(--w))}
.slice-list em{font-style:normal;font-variant-numeric:tabular-nums;text-align:right;color:var(--ink);font-weight:600}
.ov-plane{stroke:var(--ink);stroke-width:1.6;stroke-dasharray:2 4}
.ov-note.plane{fill:var(--ink)}
.plane-handle{position:absolute;left:0;top:0;width:40px;height:40px;border-radius:50%;border:2px solid var(--ink);background:color-mix(in srgb,var(--bg) 72%,transparent);cursor:ns-resize;touch-action:none;z-index:4;display:grid;place-items:center;padding:0}
.plane-handle span{width:10px;height:10px;border-radius:50%;background:var(--ink)}
.read .row.ladder-row{display:grid;grid-template-columns:minmax(0,1.15fr) minmax(0,1fr) 64px;gap:10px;align-items:center}
.ladder-row .bar{display:block;height:8px;background:var(--line);border-radius:4px}
.ladder-row .bar b{display:block;height:100%;background:var(--scan);border-radius:4px}
.ladder-row .num{text-align:right;color:var(--scan);font-weight:600}
.step-card .read{max-height:46vh;overflow:auto}
.read .row.eff{display:grid;grid-template-columns:minmax(0,1.15fr) repeat(3,minmax(0,1fr));gap:8px;font-size:13px;align-items:start}
.read .row.eff span:last-child,.read .row.eff span{text-align:left;font-weight:500;color:var(--ink-2)}
.read .row.eff span:first-child{color:var(--ink);font-weight:600}
.read .row.eff.head{font-size:11.5px;color:var(--muted)}
.read .row.eff.head span{color:var(--muted);font-weight:600}
.read .row.you{align-items:flex-start;padding:7px 0}
.read .row.you span:first-child{display:block;color:var(--ink);font-weight:600}
.read .row.you small{display:block;font-size:12.5px;font-weight:400;color:var(--muted)}
.read .row.you span:last-child{text-align:right;color:var(--scan);font-weight:600;white-space:nowrap}
.read .row.you span:last-child small{color:var(--muted)}

.hero-src{margin:14px 0 0;font-size:13px;color:var(--muted);max-width:34em}
.legend i.line{border-top:1.5px solid var(--ink-2);height:0}

.viewctl .sel select{font:600 13.5px var(--sans);padding:7px 10px;border-radius:999px;border:1px solid var(--line);background:var(--surface);color:var(--ink);min-height:44px;max-width:160px}
.viewctl{flex-wrap:wrap;justify-content:flex-end;max-width:min(520px,60vw)}
.viewctl .btn[data-spread]{font-size:12.5px}
.organ-n{position:absolute;right:max(26px,env(safe-area-inset-right));top:calc(var(--topbar) + 150px);z-index:2;margin:0;font-size:13px;color:var(--ink-2);text-align:right;max-width:min(330px,40vw)}
@media (min-width:1180px){.organ-n{right:54px}}
@media (max-width:759px){.viewctl{max-width:calc(100vw - 150px);justify-content:flex-start}.organ-n{top:auto;bottom:44px;right:12px;font-size:12px}}