/* Shared theme for the prototype documents and the landing page.
   Extracted from tools/shell.html; every page in html/ and the landing
   page at ../index.html link this one file. Edit here, not in a page. */
:root{
  --bg:#EEF1F6; --surface:#FFFFFF; --surface-2:#E4E9F1; --line:#CFD6E2; --line-strong:#AEB8C9;
  --text:#141B2B; --muted:#5B6577; --accent:#C4581A; --accent-soft:rgba(196,88,26,.12);
  --t1:#5B6577; --t2:#1E8A99; --t3:#7A3FB8;
  --star:#141B2B; --ring:rgba(196,88,26,.55); --adrift:#B34A3A;
  --shadow:0 1px 2px rgba(20,27,43,.06),0 8px 24px rgba(20,27,43,.06);
}
@media (prefers-color-scheme: dark){
  :root:not([data-theme="light"]){
    --bg:#0A0E17; --surface:#121827; --surface-2:#182033; --line:#223047; --line-strong:#334562;
    --text:#DCE3EF; --muted:#8C97AD; --accent:#F08A3E; --accent-soft:rgba(240,138,62,.14);
    --t1:#8C97AD; --t2:#4FB8C6; --t3:#C77DFF;
    --star:#DCE3EF; --ring:rgba(240,138,62,.6); --adrift:#E0654F;
    --shadow:0 1px 2px rgba(0,0,0,.4),0 8px 24px rgba(0,0,0,.35);
  }
}
:root[data-theme="dark"]{
  --bg:#0A0E17; --surface:#121827; --surface-2:#182033; --line:#223047; --line-strong:#334562;
  --text:#DCE3EF; --muted:#8C97AD; --accent:#F08A3E; --accent-soft:rgba(240,138,62,.14);
  --t1:#8C97AD; --t2:#4FB8C6; --t3:#C77DFF;
  --star:#DCE3EF; --ring:rgba(240,138,62,.6); --adrift:#E0654F;
  --shadow:0 1px 2px rgba(0,0,0,.4),0 8px 24px rgba(0,0,0,.35);
}
*{box-sizing:border-box}
html{scroll-behavior:smooth}
@media (prefers-reduced-motion: reduce){html{scroll-behavior:auto}}
body{margin:0;background:var(--bg);color:var(--text);font-family:"IBM Plex Sans",system-ui,-apple-system,"Segoe UI",Roboto,sans-serif;font-size:16px;line-height:1.6;-webkit-font-smoothing:antialiased}
a{color:var(--accent);text-decoration:none}
a:hover{text-decoration:underline}
a:focus-visible,button:focus-visible{outline:2px solid var(--accent);outline-offset:2px;border-radius:2px}
code{font-family:"IBM Plex Mono",ui-monospace,SFMono-Regular,Menlo,monospace;font-size:.88em;background:var(--surface-2);padding:.1em .35em;border-radius:3px}
strong{font-weight:600}
.num{font-family:"Chakra Petch",sans-serif;color:var(--accent);font-variant-numeric:tabular-nums}

/* header */
.hero{position:relative;border-bottom:1px solid var(--line);background:var(--surface);overflow:hidden}
.hero canvas{position:absolute;inset:0;width:100%;height:100%;display:block}
.hero-inner{position:relative;max-width:1180px;margin:0 auto;padding:56px 32px 36px;display:grid;grid-template-columns:minmax(0,1fr) 300px;gap:32px;align-items:end}
.eyebrow{font-family:"Chakra Petch",sans-serif;font-weight:600;font-size:.78rem;letter-spacing:.14em;text-transform:uppercase;color:var(--accent);margin:0 0 12px}
.eyebrow a.home{color:inherit;text-decoration:none;border-bottom:1px solid transparent;transition:border-color .15s}
.eyebrow a.home:hover{border-bottom-color:currentColor}
.hero h1{max-width:460px;font-family:"Chakra Petch",sans-serif;font-weight:700;font-size:clamp(2rem,4.5vw,3.4rem);line-height:1.05;letter-spacing:-.01em;margin:0;text-wrap:balance}
.hero h1 .sub{display:block;font-weight:500;color:var(--muted);font-size:.5em;letter-spacing:.02em;margin-top:10px}
.meta{font-family:"IBM Plex Mono",ui-monospace,monospace;font-size:.8rem;border:1px solid var(--line);background:var(--bg);padding:14px 16px;display:grid;gap:8px}
.meta-row{display:grid;gap:3px}
.meta .k{color:var(--muted);text-transform:uppercase;letter-spacing:.08em;font-size:.68rem;white-space:nowrap}
.meta .v{color:var(--text);line-height:1.45}
.meta .v strong{color:var(--accent);font-weight:500}
.meta-row:first-child .v{font-family:"Chakra Petch",sans-serif;font-size:1.05rem;font-weight:600;color:var(--accent)}

/* frame */
.frame{max-width:1180px;margin:0 auto;padding:40px 32px 96px;display:grid;grid-template-columns:230px minmax(0,1fr);gap:56px}
nav.toc{position:sticky;top:24px;align-self:start;max-height:calc(100vh - 48px);overflow:auto;font-size:.86rem}
nav.toc .label{font-family:"Chakra Petch",sans-serif;font-size:.7rem;letter-spacing:.14em;text-transform:uppercase;color:var(--muted);margin:0 0 10px;padding-left:12px}
nav.toc ol{list-style:none;margin:0;padding:0;border-left:1px solid var(--line)}
nav.toc li a{display:grid;grid-template-columns:28px 1fr;gap:6px;padding:6px 12px;color:var(--muted);line-height:1.35;border-left:2px solid transparent;margin-left:-1px}
nav.toc li a:hover{color:var(--text);text-decoration:none}
nav.toc li a.active{color:var(--text);border-left-color:var(--accent)}
nav.toc .num{font-size:.8rem;text-align:right}

/* front matter (revision history) */
.frontmatter{margin:0 0 40px;padding-bottom:32px;border-bottom:1px solid var(--line)}
.frontmatter h3{margin:0 0 10px;font-size:.78rem;letter-spacing:.14em;text-transform:uppercase;color:var(--muted)}
.frontmatter .tw{margin:0;box-shadow:none}
.frontmatter table{font-size:.82rem}
.frontmatter tbody th{color:var(--accent);font-family:"Chakra Petch",sans-serif;font-size:.9rem}
.frontmatter tbody tr:first-child th,.frontmatter tbody tr:first-child td{background:var(--accent-soft)}
.frontmatter td:nth-child(2){white-space:nowrap;font-family:"IBM Plex Mono",ui-monospace,monospace;font-size:.78rem;color:var(--muted)}
.frontmatter td:last-child{min-width:0}
/* figures */
figure{margin:24px 0 8px;padding:0}
figure+p em{color:var(--muted);font-size:.86rem}
.hud-fig{position:relative;aspect-ratio:16/9;background:var(--bg);border:1px solid var(--line-strong);overflow:hidden;font-family:"Chakra Petch",sans-serif;background-image:radial-gradient(circle,var(--line) 1px,transparent 1px);background-size:22px 22px}
.hud-fig .r{position:absolute;border:1px solid var(--accent);background:color-mix(in srgb,var(--surface) 82%,transparent);color:var(--text);font-size:.72rem;letter-spacing:.06em;text-transform:uppercase;padding:6px 8px;line-height:1.25;overflow:hidden}
.hud-fig .r b{display:inline-block;font-size:.7rem;color:var(--bg);background:var(--accent);padding:0 5px;margin-right:6px;border-radius:2px}
.hud-fig .r small{display:block;text-transform:none;letter-spacing:0;color:var(--muted);font-family:"IBM Plex Sans",sans-serif;font-size:.68rem;margin-top:3px}
.hud-fig .world{position:absolute;inset:0;pointer-events:none}
.hud-fig .world i{position:absolute;width:0;height:0;border-left:5px solid transparent;border-right:5px solid transparent;border-bottom:9px solid var(--t2);opacity:.6}
.hud-fig .world i.o{border-bottom-color:var(--accent)}
.zoom-fig{border:1px solid var(--line-strong);background:var(--bg);position:relative}
.zoom-fig canvas{display:block;width:100%;height:440px;cursor:grab}
.zoom-fig canvas:active{cursor:grabbing}
.zoom-bar{display:flex;gap:8px;align-items:center;flex-wrap:wrap;padding:8px 10px;border-top:1px solid var(--line);font-family:"IBM Plex Mono",ui-monospace,monospace;font-size:.76rem;color:var(--muted)}
.zoom-bar button{font:inherit;font-family:"Chakra Petch",sans-serif;font-weight:600;letter-spacing:.06em;text-transform:uppercase;color:var(--text);background:var(--surface-2);border:1px solid var(--line-strong);padding:4px 10px;cursor:pointer}
.zoom-bar button[aria-pressed="true"]{background:var(--accent);color:var(--bg);border-color:var(--accent)}
.zoom-bar .readout{margin-left:auto;color:var(--text)}
.zoom-fig .legend-icons{position:absolute;top:8px;left:10px;font-family:"IBM Plex Mono",ui-monospace,monospace;font-size:.7rem;color:var(--muted);pointer-events:none}
/* content */
main{min-width:0}
section{padding-bottom:40px;margin-bottom:40px;border-bottom:1px solid var(--line)}
section:last-child{border-bottom:0}
h2{font-family:"Chakra Petch",sans-serif;font-weight:700;font-size:1.9rem;line-height:1.1;margin:0 0 20px;display:flex;gap:14px;align-items:baseline;text-wrap:balance}
h2 .num{font-size:1.1rem;font-weight:600}
h3{font-family:"Chakra Petch",sans-serif;font-weight:600;font-size:1.25rem;margin:36px 0 12px;text-wrap:balance}
h4{font-family:"Chakra Petch",sans-serif;font-weight:600;font-size:.85rem;letter-spacing:.1em;text-transform:uppercase;color:var(--muted);margin:28px 0 10px}
p,ul,ol{max-width:72ch;margin:0 0 16px}
ul,ol{padding-left:1.4em}
li{margin-bottom:6px}
li::marker{color:var(--accent);font-variant-numeric:tabular-nums}
p+.tw,ul+.tw,ol+.tw{margin-top:20px}

/* tables */
.tw{overflow-x:auto;margin:0 0 24px;border:1px solid var(--line);background:var(--surface);box-shadow:var(--shadow)}
.tw[data-tier]{border-left:3px solid var(--t1)}
.tw[data-tier="2"]{border-left-color:var(--t2)}
.tw[data-tier="3"]{border-left-color:var(--t3)}
table{border-collapse:collapse;width:100%;font-size:.86rem;line-height:1.45}
th,td{padding:9px 12px;text-align:left;vertical-align:top;border-bottom:1px solid var(--line)}
thead th{font-family:"Chakra Petch",sans-serif;font-size:.72rem;letter-spacing:.1em;text-transform:uppercase;color:var(--muted);background:var(--surface-2);border-bottom:1px solid var(--line-strong);white-space:nowrap;position:sticky;top:0}
tbody tr:last-child td,tbody tr:last-child th{border-bottom:0}
tbody th{font-weight:600;white-space:nowrap}
tbody th strong{font-weight:600}
table.roster{font-family:"IBM Plex Mono",ui-monospace,SFMono-Regular,Menlo,monospace;font-size:.8rem;font-variant-numeric:tabular-nums}
table.roster tbody th{font-family:"IBM Plex Sans",system-ui,sans-serif;font-size:.86rem}
table.roster td:nth-child(3),table.roster td:nth-child(4),table.roster td:nth-child(5),table.roster td:nth-child(6){white-space:nowrap}
table.roster td:last-child{font-family:"IBM Plex Sans",system-ui,sans-serif;font-size:.84rem;min-width:22ch}
table:not(.roster) td:last-child{min-width:18ch}
tbody tr:hover td,tbody tr:hover th{background:var(--accent-soft)}

/* tier legend */
.legend{display:flex;gap:18px;flex-wrap:wrap;font-family:"IBM Plex Mono",ui-monospace,monospace;font-size:.74rem;color:var(--muted);margin:0 0 20px}
.legend span::before{content:"";display:inline-block;width:10px;height:10px;margin-right:7px;vertical-align:-1px;background:var(--t1)}
.legend .l2::before{background:var(--t2)}
.legend .l3::before{background:var(--t3)}

footer{max-width:1180px;margin:0 auto;padding:0 32px 48px;color:var(--muted);font-size:.8rem;font-family:"IBM Plex Mono",ui-monospace,monospace}

@media (max-width:900px){
  .hero-inner{grid-template-columns:1fr;padding:48px 20px 28px}
  .frame{grid-template-columns:1fr;gap:24px;padding:24px 20px 64px}
  nav.toc{position:static;max-height:none}
  nav.toc ol{columns:2;border-left:0}
  nav.toc li{break-inside:avoid}
  footer{padding:0 20px 40px}
}