/* AI Glassbox house style — calm, professional, "science museum not arcade" (PRD §12). */
:root{
  --ink:#1c2433; --muted:#5b6b86; --line:#dce3ee; --bg:#f4f7fb; --panel:#fff;
  --accent:#2f6df0; --accent-soft:#e8f0ff; --ok:#1f9d6b; --warn:#c2410c;
}
*{box-sizing:border-box}
body{margin:0;font:15px/1.6 -apple-system,BlinkMacSystemFont,"Segoe UI",Roboto,Helvetica,Arial,sans-serif;color:var(--ink);background:var(--bg)}
a{color:var(--accent);text-decoration:none}
a:hover{text-decoration:underline}
.prism{display:inline-block;width:14px;height:14px;border-radius:3px;background:linear-gradient(135deg,#2f6df0,#9b51e0,#e8703a,#1f9d6b);vertical-align:-2px;margin-right:8px}
.site-header{display:flex;align-items:center;gap:18px;padding:14px 24px;background:var(--panel);border-bottom:1px solid var(--line)}
.site-header .brand{font-size:18px;font-weight:600}
.site-header nav{margin-left:auto;display:flex;gap:18px;font-size:14px}
.hero{max-width:880px;margin:0 auto;padding:56px 24px 24px;text-align:center}
.hero h1{font-size:38px;line-height:1.15;margin:0 0 14px}
.hero p{font-size:18px;color:var(--muted);max-width:620px;margin:0 auto 24px}
.cta{display:inline-flex;gap:12px;flex-wrap:wrap;justify-content:center}
.btn{font:inherit;font-size:15px;font-weight:600;border:1px solid var(--accent);background:var(--accent);color:#fff;padding:11px 20px;border-radius:9px;cursor:pointer}
.btn.ghost{background:#fff;color:var(--accent)}
.promises{max-width:880px;margin:24px auto;display:grid;grid-template-columns:repeat(auto-fit,minmax(220px,1fr));gap:14px;padding:0 24px}
.promise{background:var(--panel);border:1px solid var(--line);border-radius:12px;padding:16px}
.promise h3{margin:0 0 6px;font-size:15px}
.promise p{margin:0;color:var(--muted);font-size:13.5px}
/* studio */
.studio{display:grid;grid-template-columns:1fr 1fr;gap:16px;padding:16px 24px;align-items:start}
.panel{background:var(--panel);border:1px solid var(--line);border-radius:12px;overflow:hidden}
.panel h2{font-size:13px;text-transform:uppercase;letter-spacing:.6px;color:var(--muted);margin:0;padding:12px 14px;border-bottom:1px solid var(--line)}
textarea#code{width:100%;min-height:360px;border:0;padding:14px;font:13.5px/1.6 "SF Mono",ui-monospace,Menlo,Consolas,monospace;resize:vertical;background:#fbfcfe;outline:none;color:var(--ink)}
.toolbar{display:flex;gap:8px;align-items:center;padding:10px 14px;border-top:1px solid var(--line);background:#fafbfe;flex-wrap:wrap}
button{font:inherit;font-size:14px;border:1px solid var(--line);background:#fff;color:var(--ink);padding:8px 14px;border-radius:8px;cursor:pointer}
button.primary{background:var(--accent);border-color:var(--accent);color:#fff;font-weight:600}
select{font:inherit;padding:7px 9px;border-radius:8px;border:1px solid var(--line);background:#fff}
.out{padding:12px 14px;max-height:560px;overflow:auto}
.log{font:13px/1.55 "SF Mono",ui-monospace,Menlo,monospace;white-space:pre-wrap;color:#243049}
.err{color:var(--warn);font-weight:600;white-space:pre-wrap}
.hint{color:var(--muted);font-size:12.5px;padding:6px 0}
table.cm{border-collapse:collapse;font-size:12.5px;margin:6px 0}
table.cm td,table.cm th{border:1px solid var(--line);padding:4px 8px;text-align:center}
.net{display:flex;gap:34px;align-items:center;padding:10px 4px;flex-wrap:wrap}
.net .col{display:flex;flex-direction:column;gap:7px;align-items:center}
.net .neuron{width:18px;height:18px;border-radius:50%;background:var(--accent-soft);border:1.5px solid var(--accent)}
.net .label{font-size:11px;color:var(--muted);margin-top:4px;text-transform:uppercase;letter-spacing:.4px}
/* decision tree */
.tree{font-size:13px;padding:4px 0}
.tree-node{padding:2px 0}
.tree-q{display:inline-block;background:var(--accent-soft);border:1px solid var(--accent);border-radius:7px;padding:3px 9px;font-weight:600;color:#1c3a8a}
.tree-leaf{display:inline-block;background:#e7f6ee;border:1px solid var(--ok);border-radius:7px;padding:3px 9px;color:#0f6b48;font-weight:600}
.tree-branch{margin:3px 0 3px 10px;border-left:2px solid var(--line);padding-left:8px}
.tree-edge{font-size:11px;color:var(--muted);margin-left:2px}
/* train/test split */
.split-bar{display:flex;height:30px;border-radius:8px;overflow:hidden;border:1px solid var(--line);margin:6px 0;font-size:11.5px;font-weight:600}
.split-train{background:#cdeede;color:#0f6b48;display:flex;align-items:center;justify-content:center;min-width:44px}
.split-test{background:#d8e6ff;color:#1c3a8a;display:flex;align-items:center;justify-content:center;min-width:44px}
/* data viewer */
table.data-table{border-collapse:collapse;font-size:12px;margin:6px 0}
table.data-table td,table.data-table th{border:1px solid var(--line);padding:3px 8px;text-align:left}
table.data-table th{background:var(--accent-soft);font-weight:600}
.data-stats{margin:6px 0;font-size:12px;color:var(--muted);padding-left:18px}
/* feature importance */
.imp{margin:6px 0;display:flex;flex-direction:column;gap:5px}
.imp-row{display:flex;align-items:center;gap:8px;font-size:12.5px}
.imp-name{width:110px;text-align:right;color:var(--ink)}
.imp-track{flex:1;background:#eef2f8;border-radius:6px;height:14px;overflow:hidden}
.imp-bar{height:100%;background:var(--accent);min-width:2px}
.imp-pct{width:48px;color:var(--muted)}
/* random forest */
.forest{font-size:22px;line-height:1.4;margin:4px 0}
.forest-tree{margin-right:1px}
/* generated text samples */
.gen-list{margin:6px 0;font-size:13px;padding-left:18px}
/* transformer attention heatmap */
table.attn{border-collapse:collapse;font-size:12px;margin:6px 0}
table.attn td,table.attn th{border:1px solid var(--line);padding:4px 7px;text-align:center;min-width:30px}
table.attn th{background:var(--accent-soft);font-weight:600;color:#1c3a8a;font-size:11.5px}
/* q-learning gridworld */
.qgrid{display:grid;gap:3px;margin:8px 0}
.qcell{position:relative;width:46px;height:46px;border:1px solid var(--line);border-radius:7px;background:#fbfcfe;display:flex;align-items:center;justify-content:center;font-size:13px}
.qcell.q-goal{background:#e7f6ee;border-color:var(--ok);color:#0f6b48;font-weight:700}
.qcell.q-pit{background:#fbe7df;border-color:var(--warn);color:#9a3412;font-weight:700}
.qcell.q-on-path{box-shadow:inset 0 0 0 2px var(--accent)}
.q-arrow{font-size:20px;color:#1c3a8a;line-height:1}
.q-start{position:absolute;top:2px;left:4px;font-size:10px;font-weight:700;color:var(--muted)}
/* gallery */
.gallery{max-width:980px;margin:8px auto 24px;display:grid;grid-template-columns:repeat(auto-fill,minmax(260px,1fr));gap:14px;padding:0 24px}
.app-card{background:var(--panel);border:1px solid var(--line);border-radius:12px;padding:16px;display:flex;flex-direction:column;gap:8px}
.app-card h3{margin:0;font-size:16px}
.app-card p{margin:0;color:var(--muted);font-size:13.5px;flex:1}
.app-card .meta{font-size:12px;color:var(--muted);display:flex;gap:10px;align-items:center}
.app-card .tag{background:var(--accent-soft);color:#1c3a8a;border-radius:20px;padding:2px 9px;font-weight:600}
.gallery-empty{max-width:880px;margin:0 auto;padding:0 24px;color:var(--muted)}
/* deployed-app player */
.play{max-width:760px;margin:8px auto 24px;padding:0 24px}
.play .panel{padding:0}
.play .app-head{padding:16px;border-bottom:1px solid var(--line)}
.play .app-head h1{margin:0 0 6px;font-size:22px}
.play .app-head p{margin:0;color:var(--muted);font-size:14px}
.site-footer{padding:18px 24px 32px;color:var(--muted);font-size:12.5px;text-align:center}
/* simulations */
.sim{max-width:760px;margin:0 auto;padding:20px 24px 8px}
.sim-crumb{color:var(--muted);font-size:13px;margin:0 0 6px}
.sim h1{font-size:30px;margin:0 0 14px}
.sim-block{margin:22px 0}
.sim-block h2{font-size:13px;text-transform:uppercase;letter-spacing:.6px;color:var(--muted);margin:0 0 8px}
.sim-block p{margin:0 0 10px}
.sim-block ul{margin:0;padding-left:20px}
.sim-block li{margin:5px 0}
.sim-deeper,.sim-howto{color:var(--muted);font-size:13.5px}
.sim-code{background:#fbfcfe;border:1px solid var(--line);border-radius:10px;padding:14px;font:13px/1.6 "SF Mono",ui-monospace,Menlo,Consolas,monospace;white-space:pre-wrap;color:#243049;margin:0 0 12px}
.sim-controls{display:flex;gap:18px;align-items:center;flex-wrap:wrap;background:var(--panel);border:1px solid var(--line);border-radius:12px;padding:12px 14px}
.sim-controls label{font-size:13.5px;color:var(--muted);display:flex;align-items:center;gap:8px}
.sim-controls input[type=range]{vertical-align:middle}
.sim-ends{font-size:11.5px;color:var(--muted)}
.sim-words{display:flex;gap:8px;flex-wrap:wrap;margin:14px 0 4px}
.sim-chip{display:flex;flex-direction:column;align-items:center;gap:2px;padding:7px 11px;border:1px solid var(--line);border-radius:9px;background:#fff;cursor:pointer;line-height:1.2}
.sim-chip.sel{border-color:var(--accent);background:var(--accent-soft)}
.sim-chip-word{font-weight:600;font-size:14px;color:var(--ink)}
.sim-chip-tag{font-size:10px;text-transform:uppercase;letter-spacing:.4px;color:var(--muted)}
.sim-explain{margin:8px 0;font-size:14px;color:#243049;background:var(--accent-soft);border-radius:9px;padding:10px 12px}
table.attn tr.sel th{background:var(--accent);color:#fff}
.sim-whatif{margin:12px 0;font-size:13.5px;color:var(--muted);border-left:3px solid var(--accent);padding-left:12px}
/* line-of-best-fit sim (SVG) */
.sim-svg{display:block;width:100%;height:auto;background:var(--panel);border:1px solid var(--line);border-radius:12px;touch-action:none}
.sim-svg .axis{stroke:var(--line);stroke-width:1.5}
.sim-svg .axlabel{fill:var(--muted);font-size:11px;text-anchor:middle}
.sim-svg .pt{fill:var(--ink)}
.sim-svg .resid{stroke:var(--warn);stroke-width:2;opacity:.65}
.sim-svg .fit-line{stroke:var(--accent);stroke-width:3;stroke-linecap:round}
.sim-svg .best-line{stroke:var(--ok);stroke-width:2.5;stroke-dasharray:6 5;stroke-linecap:round}
.sim-svg .handle{fill:#fff;stroke:var(--accent);stroke-width:3;cursor:grab}
.sim-svg .handle:focus{outline:none;stroke:#1c3a8a}
.sim-svg .handle.drag{cursor:grabbing;fill:var(--accent-soft)}
.sim-read{margin:14px 0 6px}
.sim-num-label{font-size:12.5px;color:var(--muted);margin-bottom:5px}
.fit-bar{height:18px;background:#eef2f8;border-radius:9px;overflow:hidden;border:1px solid var(--line)}
.fit-bar-in{height:100%;background:var(--warn);width:0;transition:width .08s linear}
.fit-bar-in.win{background:var(--ok)}
.sim-num{font-size:13.5px;color:#243049;margin-top:6px;font-weight:600}
/* k-nearest-neighbors sim (SVG) */
.knn-capture{cursor:crosshair}
.sim-svg .knn-a{fill:#d23b3b}
.sim-svg .knn-b{fill:#e0a500}
.sim-svg .knn-link{stroke:var(--muted);stroke-width:1.5;opacity:.5}
.sim-svg .knn-ring{fill:none;stroke-width:2.5}
.sim-svg .knn-ring.is-a{stroke:#d23b3b}
.sim-svg .knn-ring.is-b{stroke:#e0a500}
.sim-svg .knn-q{stroke:#1c2433;stroke-width:2.5;fill:#fff}
.sim-svg .knn-q.is-a{fill:#f6d0d0}
.sim-svg .knn-q.is-b{fill:#f7e6b0}
.sim-svg .knn-qmark{text-anchor:middle;font-size:13px;font-weight:700;fill:var(--ink)}
.knn-vote{font-size:14px;color:#243049}
.knn-tally-a{color:#b32d2d;font-weight:600}
.knn-tally-b{color:#a87800;font-weight:600}
/* k-means sim (SVG) */
.sim-svg .km-pt{stroke:#fff;stroke-width:1}
.sim-svg .km-link{stroke-width:1.2;opacity:.35}
.sim-svg .km-cen{stroke:#1c2433;stroke-width:2.5}
.km-status{font-size:13.5px;color:#243049}
/* gradient descent sim (SVG) */
.sim-svg .gd-curve{fill:none;stroke:var(--line);stroke-width:3}
.sim-svg .gd-tangent{stroke:var(--warn);stroke-width:2.5;stroke-linecap:round}
.sim-svg .gd-trail{fill:var(--accent)}
.sim-svg .gd-ball{fill:var(--accent);stroke:#fff;stroke-width:2}
.gd-status{font-size:13.5px;color:#243049}
.gd-status.warn{color:var(--warn);font-weight:600}
/* randomness & probability sim (SVG) */
.sim-svg .prob-grid{stroke:var(--line);stroke-width:1}
.sim-svg .prob-ylab{fill:var(--muted);font-size:10px;text-anchor:end}
.sim-svg .prob-true{stroke:var(--ok);stroke-width:2;stroke-dasharray:6 5}
.sim-svg .prob-line{fill:none;stroke:var(--accent);stroke-width:2}
.sim-svg .prob-blue{fill:var(--accent)}
.sim-svg .prob-white{fill:#fff}
.sim-svg .prob-rim{fill:none;stroke:var(--line);stroke-width:1.5}
.sim-svg .prob-wlab{fill:var(--muted);font-size:11px;text-anchor:middle}
.prob-status{font-size:13.5px;color:#243049}
@media(max-width:780px){.studio{grid-template-columns:1fr}}