:root{
  color-scheme:light;
  --bg:#fafaf9;--surface:#fff;--sunken:#f2f2f0;
  --text:#141413;--text-2:#55554f;--text-3:#86857e;
  --line:#e6e5e1;--line-strong:#d2d1cb;
  --link:#1f5fb0;--focus:#2a78d6;
  --s1:#2a78d6;--s2:#eb6834;--track:#ecebe7;
  --c1:#2a78d6;--c2:#eb6834;--c3:#1baf7a;--c4:#eda100;--c5:#e87ba4;--c6:#008300;
  --good:#176a42;--bad:#a54400;
  --sans:ui-sans-serif,-apple-system,BlinkMacSystemFont,"Segoe UI",Roboto,"Helvetica Neue",Arial,sans-serif;
  --mono:ui-monospace,SFMono-Regular,Menlo,Consolas,"Liberation Mono",monospace;
  --radius:8px;--gutter:16px;
}
@media (prefers-color-scheme:dark){:root:not([data-theme="light"]){
  color-scheme:dark;
  --bg:#111110;--surface:#1a1a19;--sunken:#222220;
  --text:#f2f1ec;--text-2:#b9b8b0;--text-3:#8a8982;
  --line:#2b2b29;--line-strong:#3a3a37;
  --link:#7fb1f0;--focus:#3987e5;
  --s1:#3987e5;--s2:#d95926;--track:#2a2a28;
  --c1:#3987e5;--c2:#d95926;--c3:#199e70;--c4:#c98500;--c5:#d55181;--c6:#008300;
  --good:#5cc08a;--bad:#f08a4b;
}}
:root[data-theme="dark"]{
  color-scheme:dark;
  --bg:#111110;--surface:#1a1a19;--sunken:#222220;
  --text:#f2f1ec;--text-2:#b9b8b0;--text-3:#8a8982;
  --line:#2b2b29;--line-strong:#3a3a37;
  --link:#7fb1f0;--focus:#3987e5;
  --s1:#3987e5;--s2:#d95926;--track:#2a2a28;
  --c1:#3987e5;--c2:#d95926;--c3:#199e70;--c4:#c98500;--c5:#d55181;--c6:#008300;
  --good:#5cc08a;--bad:#f08a4b;
}

*{box-sizing:border-box}
html{font:15px/1.6 var(--sans);-webkit-text-size-adjust:100%}
body{margin:0;background:var(--bg);color:var(--text)}
a{color:var(--link);text-decoration:underline;text-decoration-thickness:1px;text-underline-offset:2px}
a:hover{text-decoration-thickness:2px}
:focus-visible{outline:2px solid var(--focus);outline-offset:2px}
.num,td,.stat b{font-variant-numeric:tabular-nums}

/* Top bar */
.topbar{position:sticky;top:0;z-index:5;background:color-mix(in srgb,var(--bg) 88%,transparent);backdrop-filter:blur(8px);border-bottom:1px solid var(--line)}
.topbar-inner{max-width:1120px;margin:auto;padding:0 24px;height:52px;display:flex;align-items:center;gap:24px}
.brand{font-weight:650;color:var(--text);text-decoration:none;display:flex;align-items:center;gap:10px;white-space:nowrap}
.brand::before{content:"";width:16px;height:14px;background:repeating-linear-gradient(90deg,currentColor 0 2px,transparent 2px 3px,currentColor 3px 4px,transparent 4px 6px,currentColor 6px 9px,transparent 9px 10px)}
.topbar nav{display:flex;gap:4px;overflow-x:auto;scrollbar-width:none;margin-left:auto}
.topbar nav a{color:var(--text-2);text-decoration:none;padding:6px 10px;border-radius:6px;font-size:14px;white-space:nowrap}
.topbar nav a:hover,.topbar nav a[aria-current]{color:var(--text);background:var(--sunken)}

main{max-width:1120px;margin:auto;padding:48px 24px 0}
h1{font-size:clamp(28px,4vw,40px);line-height:1.15;letter-spacing:-.02em;font-weight:650;margin:0 0 14px}
h2{font-size:22px;letter-spacing:-.01em;font-weight:650;margin:0 0 6px}
h3{font-size:16px;font-weight:600;margin:0 0 6px}
p{margin:0 0 12px}
.lead{font-size:17px;color:var(--text-2);max-width:68ch}
.meta{font-size:13px;color:var(--text-3);margin-bottom:28px}
.note,footer{font-size:13px;color:var(--text-2)}
.muted{color:var(--text-3)}
section{margin-top:64px;scroll-margin-top:72px}
.section-head{display:flex;justify-content:space-between;align-items:end;gap:16px;flex-wrap:wrap;margin-bottom:20px}
.section-head p{color:var(--text-2);margin:0;max-width:72ch}

/* Stats row */
.stats{display:grid;grid-template-columns:repeat(4,1fr);margin:32px 0 0;border:1px solid var(--line);border-radius:var(--radius);background:var(--surface)}
.stat{padding:16px 20px;border-left:1px solid var(--line)}
.stat:first-child{border-left:0}
.stat b{display:block;font-size:24px;font-weight:600;letter-spacing:-.01em}
.stat span{font-size:13px;color:var(--text-2)}

aside,.callout{font-size:14px;color:var(--text-2);background:var(--sunken);border-radius:var(--radius);padding:12px 16px;margin:16px 0}
aside strong{color:var(--text)}

/* Legend */
.legend{display:flex;gap:18px;flex-wrap:wrap;font-size:13px;color:var(--text-2)}
.legend span{display:inline-flex;align-items:center;gap:7px}
.legend i{width:10px;height:10px;border-radius:2px;display:inline-block}
.legend span.pending{color:var(--text-3)}

/* Results matrix */
.mode-toggle{display:inline-flex;align-items:center;gap:8px;font-size:14px;color:var(--text-2);margin-bottom:12px;cursor:pointer}
.mode-toggle input{accent-color:var(--text)}
.mode-toggle[hidden]{display:none}
table.matrix thead th.group{text-align:center;color:var(--text);border-bottom:1px solid var(--line);padding-bottom:6px}
table.matrix thead tr:nth-child(2) th{padding-top:6px}
.matrix-wrap{background:var(--surface)}
table.matrix{min-width:980px;table-layout:fixed}
table.matrix th,table.matrix td{padding:12px 14px;white-space:normal;vertical-align:middle}
table.matrix thead th{color:var(--text-2);font-weight:550;font-size:12px}
table.matrix thead th .swatch{margin-right:6px;vertical-align:-1px}
table.matrix thead th:first-child,table.matrix tbody th{width:180px}
table.matrix tbody th{text-align:left;font-weight:400;font-size:14px}
table.matrix tbody th a{color:var(--text);text-decoration:none;font-weight:550}
table.matrix tbody th a:hover{text-decoration:underline}
table.matrix small{display:block;font-size:12px;color:var(--text-3);font-variant-numeric:tabular-nums}
table.matrix td .line{display:flex;align-items:center;gap:8px}
table.matrix td b{font-weight:600;font-variant-numeric:tabular-nums}
.bar{flex:1;height:6px;min-width:24px;background:var(--track);border-radius:3px;overflow:hidden}
.bar i{display:block;height:100%;border-radius:0 3px 3px 0;background:var(--s1)}
.pending{color:var(--text-3)}

/* Figures */
.figure{border:1px solid var(--line);border-radius:var(--radius);background:var(--surface);padding:20px;margin-top:20px}
.figure figcaption{display:flex;justify-content:space-between;gap:12px;flex-wrap:wrap;margin-bottom:12px}
.figure figcaption p{margin:0;font-size:13px;color:var(--text-2)}
.chart{display:block;max-width:100%;overflow:visible}
.chart text{font:12px var(--sans);fill:var(--text-2);font-variant-numeric:tabular-nums}
.chart .grid line{stroke:var(--line)}
.chart .val{fill:var(--text);font-weight:600}
.chart rect.hit{fill:transparent}
.chart g.b:hover rect.mark{opacity:.85}

/* Challenge sections */
.challenge{background:var(--surface);border:1px solid var(--line);border-radius:var(--radius);padding:24px;margin-bottom:20px;scroll-margin-top:72px}
.challenge-head{display:flex;justify-content:space-between;align-items:start;gap:20px;margin-bottom:20px}
.challenge-head h3{font-size:18px;margin-bottom:6px}
.challenge-head p{font-size:14px;color:var(--text-2);margin:0;max-width:80ch}
.badge{font-size:12px;color:var(--text-2);background:var(--sunken);padding:4px 10px;border-radius:999px;white-space:nowrap}
.challenge-body{display:grid;grid-template-columns:minmax(0,320px) minmax(0,1fr);gap:28px;align-items:start;margin-bottom:20px}
.media{display:grid;gap:8px;font-size:13px}
.thumb{aspect-ratio:4/3;background:var(--sunken);border-radius:6px;overflow:hidden;display:grid;place-items:center}
.thumb img{width:100%;height:100%;object-fit:contain;display:block}
.thumb.rot img{width:62%;height:62%;transform:rotate(45deg)}
.swatch{width:10px;height:10px;border-radius:2px;display:inline-block;flex:none}
.compare{display:grid;gap:2px;align-content:start}
.crow{display:grid;grid-template-columns:minmax(150px,1.2fr) minmax(80px,2fr) 56px 70px;gap:12px;align-items:center;padding:7px 0;border-top:1px solid var(--line);font-size:14px}
.crow b{text-align:right;font-weight:600;font-variant-numeric:tabular-nums}
.crow .ms{text-align:right;color:var(--text-2);font-size:13px;font-variant-numeric:tabular-nums}
.chead{border-top:0;font-size:12px;color:var(--text-3);padding-top:0}
.chead span:nth-child(3),.chead span:nth-child(4){text-align:right}
.cname{display:flex;align-items:center;gap:4px 8px;flex-wrap:wrap;min-width:0}
.clabel{display:inline-flex;align-items:center;gap:8px;white-space:nowrap}
.crow.empty .cname{color:var(--text-3)}
.tag{font-size:11px;font-weight:500;color:var(--text);background:var(--sunken);border:1px solid var(--line-strong);border-radius:999px;padding:0 7px;line-height:18px}
table.matrix td.best{background:var(--sunken)}
td.best b{text-decoration:underline;text-decoration-thickness:2px;text-underline-offset:3px}
table.matrix tbody th{position:sticky;left:0;background:var(--surface);z-index:1}
.challenge>.scroll{margin-top:4px}
.challenge>.note{margin:12px 0 0}
.figure{margin:0 0 20px;padding:16px 18px}
.figure figcaption{display:flex;justify-content:space-between;align-items:center;gap:12px;flex-wrap:wrap;margin-bottom:8px}
.figure h4{margin:0;font-size:14px;font-weight:600}
.figure .legend .pending{color:var(--text-3)}
.plot{margin-bottom:12px}
.chart circle{transition:r .1s}
.series:hover path{stroke-width:3}

/* Method */
.method{display:grid;grid-template-columns:repeat(2,minmax(0,1fr));gap:32px 40px}
.method article p{font-size:14px;color:var(--text-2)}

/* Generic */
details{margin-top:12px}
summary{cursor:pointer;color:var(--text-2);font-size:14px}
summary:hover{color:var(--text)}
details[open]>summary{margin-bottom:10px}
.scroll{overflow:auto;border:1px solid var(--line);border-radius:var(--radius)}
table{border-collapse:collapse;width:100%;background:var(--surface);font-size:13px}
th,td{padding:9px 12px;text-align:left;border-bottom:1px solid var(--line);white-space:nowrap}
tr:last-child td{border-bottom:0}
th{font-weight:500;color:var(--text-3);font-size:12px;background:var(--surface)}
td:first-child{font-weight:500}
td span,td small{display:block;font-weight:400;color:var(--text-3)}
.links{display:flex;flex-wrap:wrap;gap:6px 16px;font-size:13px}
code{font:12px/1.5 var(--mono);overflow-wrap:anywhere;white-space:pre-wrap;color:var(--text-2)}
footer{max-width:1120px;margin:80px auto 0;padding:24px 24px 40px;border-top:1px solid var(--line);display:flex;justify-content:space-between;gap:16px;flex-wrap:wrap}

/* Shared form controls (dataset, observations, runner pages) */
button{font:inherit;font-size:14px;border:1px solid var(--line-strong);background:var(--surface);color:var(--text);padding:7px 14px;border-radius:6px;cursor:pointer}
button:hover:not(:disabled){background:var(--sunken)}
button:disabled{opacity:.5;cursor:default}
#start{background:var(--text);color:var(--bg);border-color:var(--text)}
input,select{font:inherit;font-size:14px;padding:7px 10px;border:1px solid var(--line-strong);border-radius:6px;max-width:100%;background:var(--surface);color:var(--text)}
label{font-size:14px;color:var(--text-2)}
progress{accent-color:var(--s1)}
#results td{white-space:normal;overflow-wrap:anywhere}

/* Page-level grids used by dataset/observations */
.grid{display:grid;grid-template-columns:repeat(2,minmax(0,1fr));gap:16px}
.grid>article{background:var(--surface);border:1px solid var(--line);border-radius:var(--radius);padding:18px;min-width:0}
.grid>article p{overflow-wrap:anywhere;font-size:14px}
.grid>article aside{margin:8px 0}
.gallery-tools,.variant-actions,.inspect-controls{display:flex;gap:10px;flex-wrap:wrap;align-items:end;margin:20px 0}
.gallery-tools label{display:grid;gap:4px}
.gallery-card{min-width:0}
.gallery-card canvas.thumbnail{width:100%;height:260px;object-fit:contain;background:var(--sunken);border-radius:6px;margin:14px 0}
.gallery-card select{width:100%}
.gallery-card .variant-note{min-height:3em;font-size:13px;color:var(--text-2)}
#count{font-size:13px;color:var(--text-2)}
dialog{width:95vw;max-width:1400px;max-height:95vh;border:1px solid var(--line-strong);border-radius:12px;background:var(--surface);color:inherit;padding:20px}
dialog::backdrop{background:#000a}
.pixel-view{overflow:auto;max-height:65vh;background:var(--sunken)}
.pixel-view canvas{display:block;max-width:none}
.inspect-controls{margin:0;align-items:center}
.inspect-controls strong{flex:1}
body:has(dialog[open]){overflow:hidden}

@media (max-width:900px){
  .challenge-body{grid-template-columns:1fr}
  .media{max-width:420px}
}
@media (max-width:640px){
  .topbar-inner{padding:0 var(--gutter);gap:12px}
  .brand span{display:none}
  main{padding:32px var(--gutter) 0}
  footer{padding:24px var(--gutter) 32px}
  .stats{grid-template-columns:repeat(2,1fr)}
  .stat:nth-child(3){border-left:0}
  .stat:nth-child(n+3){border-top:1px solid var(--line)}
  .grid,.method{grid-template-columns:1fr}
  .challenge{padding:16px}
  .challenge-head{flex-direction:column;gap:8px}
  .crow{grid-template-columns:minmax(110px,1fr) minmax(50px,1fr) 50px 58px;gap:8px;font-size:13px}
  .gallery-card canvas.thumbnail{height:220px}
}