:root{--ink:#14213d;--muted:#66758b;--paper:#f7f9fc;--card:#fff;--line:#d9e1ec;--accent:#315f9c;--accent2:#7652a3;--good:#2f7d5a;--bad:#a51c30;--gold:#c49a3a;--cyan:#2e8594}
*{box-sizing:border-box} html{scroll-behavior:smooth}
body{margin:0;font-family:Inter,ui-sans-serif,system-ui,-apple-system,BlinkMacSystemFont,"Segoe UI",sans-serif;background:var(--paper);color:var(--ink);line-height:1.5}
a{color:inherit}.container{width:min(1200px,calc(100% - 32px));margin:auto}
.site-header{background:#101b32;color:#fff;border-bottom:1px solid rgba(255,255,255,.08)}
.nav-shell{min-height:64px;display:flex;align-items:center;justify-content:space-between;gap:20px}.brand{display:flex;align-items:center;gap:10px;text-decoration:none;font-weight:800}.brand-mark{display:grid;place-items:center;width:40px;height:40px;border-radius:10px;background:#fff;color:#a51c30;font-weight:900}.site-nav{display:flex;gap:4px;flex-wrap:wrap;justify-content:flex-end}.site-nav a{padding:8px 10px;border-radius:8px;text-decoration:none;color:#dbe5f2;font-size:13px}.site-nav a:hover,.site-nav a.current{background:rgba(255,255,255,.11);color:#fff}
.hero{background:linear-gradient(135deg,#17294b,#253c68);color:#fff;padding:34px 0 30px}.hero .kicker{margin:0 0 8px;text-transform:uppercase;letter-spacing:.12em;font-size:12px;color:#c8d5e8;font-weight:800}.hero h1{margin:0 0 8px;font-size:clamp(31px,4.5vw,50px);line-height:1.03;letter-spacing:-.03em}.hero p{max-width:920px;margin:0;color:#dbe5f2;font-size:16px}.pills{display:flex;gap:8px;flex-wrap:wrap;margin-top:16px}.pill{padding:5px 9px;border-radius:999px;background:rgba(255,255,255,.1);border:1px solid rgba(255,255,255,.15);font-size:12px}
main{padding:24px 0 44px}.footer{border-top:1px solid var(--line);padding:20px 0 32px;color:#718096;font-size:13px}
.grid{display:grid;grid-template-columns:repeat(2,minmax(0,1fr));gap:16px}.card,.panel{background:var(--card);border:1px solid var(--line);border-radius:16px}.card{padding:20px}.card h2{margin:4px 0 8px;font-size:22px}.card p{margin:0 0 14px;color:#4d5d74}.meta{font-size:12px;text-transform:uppercase;letter-spacing:.08em;color:var(--muted);font-weight:800}.card-link{display:inline-block;text-decoration:none;color:#fff;background:var(--accent);padding:9px 13px;border-radius:9px;font-weight:750}
.activity-layout{display:grid;grid-template-columns:minmax(0,1.6fr) minmax(315px,.75fr);gap:18px;align-items:start}.panel{padding:17px;min-width:0}.side-panel{position:sticky;top:14px}.panel h2{margin:0 0 10px;font-size:20px}.panel h3{margin:17px 0 7px;font-size:15px}
.prompt{background:#fff8df;border-left:5px solid var(--gold);border-radius:12px;padding:13px 15px;margin-bottom:16px;font-size:15px}.note{border-radius:12px;padding:12px 14px;background:#f7f9fc;border:1px solid var(--line);margin:10px 0}.insight{border-radius:12px;padding:12px 14px;background:#eef6f1;border:1px solid #cce4d6;color:#285b44}.warning{border-radius:12px;padding:12px 14px;background:#fff4f4;border:1px solid #edd0d0;color:#7b3030}
.controls{display:flex;gap:9px;flex-wrap:wrap;align-items:center;margin:9px 0}.controls label,.control-block label{font-size:13px;font-weight:700;color:var(--ink)}select,input[type=number],input[type=text]{font:inherit;padding:8px 9px;border:1px solid #becadd;border-radius:8px;background:#fff;color:var(--ink)}input[type=range]{accent-color:var(--accent);max-width:180px}button{border:0;border-radius:9px;padding:9px 12px;background:#e8eef6;color:var(--ink);border:1px solid #cbd6e5;font:inherit;font-weight:750;cursor:pointer}button.primary{background:var(--accent);color:#fff;border-color:var(--accent)}button.purple{background:var(--accent2);color:#fff;border-color:var(--accent2)}button.selected{background:var(--accent2);color:#fff;border-color:var(--accent2)}button:disabled{opacity:.45;cursor:not-allowed}
.canvas-wrap{width:100%;overflow:auto;border:1px solid #e2e8f0;border-radius:12px;background:#fff}.canvas-wrap canvas,.canvas-wrap svg{display:block;width:100%;height:auto;min-width:560px;border:0;background:#fff;touch-action:none}.mini-grid{display:grid;grid-template-columns:repeat(3,minmax(0,1fr));gap:9px;margin-top:12px}.mini-card{border:1px solid var(--line);border-radius:12px;background:#fff;padding:8px}.mini-card h4{font-size:12px;margin:0 0 6px;color:#526176}.mini-card canvas{width:100%;height:auto;display:block;border-radius:8px;border:1px solid #e5eaf1}
.stat-grid{display:grid;grid-template-columns:repeat(3,minmax(0,1fr));gap:9px;margin:10px 0}.stat{border:1px solid var(--line);border-radius:12px;padding:10px;background:#fafcff}.stat .label{display:block;color:var(--muted);font-size:11px;text-transform:uppercase;letter-spacing:.05em}.stat .num{display:block;font-size:23px;font-weight:850;letter-spacing:-.02em;color:var(--ink);margin-top:2px}.small{font-size:12.5px;color:var(--muted)}.legend{display:flex;gap:12px;flex-wrap:wrap;margin:8px 0;color:#526176;font-size:12px}.dot{display:inline-block;width:11px;height:11px;border-radius:3px;margin-right:4px;vertical-align:-1px}.bar{height:16px;border-radius:999px;background:#e8edf4;overflow:hidden;position:relative}.bar>span{display:block;height:100%;border-radius:999px}.bar label{position:absolute;left:8px;top:-1px;font-size:12px;color:#172033}.formula{font-family:ui-monospace,SFMono-Regular,Menlo,monospace;background:#f3f6fa;border:1px solid #e0e6ef;border-radius:9px;padding:10px;font-size:13px;overflow:auto}.contrib{display:grid;grid-template-columns:1fr auto;gap:4px 12px;font-size:13px}.contrib span:nth-child(even){font-family:ui-monospace,SFMono-Regular,Menlo,monospace;font-weight:700}.steps{display:flex;gap:6px;flex-wrap:wrap;margin:10px 0}.step-pill{padding:5px 8px;border-radius:999px;background:#edf1f6;font-size:12px;color:#5b6b80}.step-pill.on{background:#dce8f7;color:#234a7c;font-weight:800}
svg{width:100%;height:auto;display:block}.node{fill:#fff;stroke:#4d5b70;stroke-width:2}.node.active{fill:#edf4fb;stroke:#315f9c}.node.dead{fill:#f3f3f3;stroke:#aaa}.node-text{font-size:12px;text-anchor:middle;dominant-baseline:central}.value-text{font-size:11px;text-anchor:middle;fill:#315f9c;font-weight:bold}.edge-label{font-size:10px;fill:#4f5d70;text-anchor:middle}.grad-label{font-size:10px;fill:#6a3c76;text-anchor:middle;font-weight:bold}hr{border:0;height:1px;background:#e2e8f0;margin:15px 0}.two-col{display:grid;grid-template-columns:1fr 1fr;gap:10px}.table{width:100%;border-collapse:collapse;font-size:12px}.table th,.table td{border:1px solid var(--line);padding:6px;text-align:right}.table th{background:#f4f7fb}.table th:first-child,.table td:first-child{text-align:left}
@media(max-width:930px){.activity-layout{grid-template-columns:1fr}.side-panel{position:static}.site-nav{display:none}.grid{grid-template-columns:1fr}}
@media(max-width:650px){.container{width:min(100% - 18px,1200px)}.hero{padding:27px 0}.panel,.card{padding:13px}.mini-grid,.stat-grid,.two-col{grid-template-columns:1fr}.canvas-wrap canvas,.canvas-wrap svg{min-width:520px}}