:root{--bg:#dcdcd4;--panel:#f3f3ee;--ink:#1c1c1a;--muted:#5d5d57;--line:#b9b9b0;--accent:#1c1c1a;--grid:#00000059;--good:#1f7a3a;--bad:#b3261e;--good-bg:#d9efdf;--bad-bg:#f5dcda}@media (prefers-color-scheme:dark){:root:not([data-theme=light]){--bg:#2a2a28;--panel:#353533;--ink:#efefe9;--muted:#a8a8a0;--line:#4d4d49;--accent:#efefe9;--grid:#ffffff59;--good:#7fd69a;--bad:#f28b82;--good-bg:#24402c;--bad-bg:#4a2a28}}:root[data-theme=dark]{--bg:#2a2a28;--panel:#353533;--ink:#efefe9;--muted:#a8a8a0;--line:#4d4d49;--accent:#efefe9;--grid:#ffffff59;--good:#7fd69a;--bad:#f28b82;--good-bg:#24402c;--bad-bg:#4a2a28}*{box-sizing:border-box}body{background:var(--bg);color:var(--ink);margin:0;font-family:Space Grotesk,system-ui,-apple-system,Segoe UI,sans-serif;line-height:1.45}main{max-width:900px;margin:0 auto;padding:28px 20px 56px}h1{letter-spacing:-.01em;margin:0 0 4px;font-size:clamp(22px,3.4vw,30px);font-weight:700}p.lead{color:var(--muted);max-width:60ch;margin:0 0 18px}.tabs{border-bottom:1px solid var(--line);gap:6px;margin-bottom:22px;display:flex}.tabs button{color:var(--muted);background:0 0;border:none;border-bottom:3px solid #0000;border-radius:0;margin-bottom:-1px;padding:8px 14px;font-size:16px}.tabs button[aria-selected=true]{color:var(--ink);border-bottom-color:var(--ink);font-weight:700}.controls{flex-wrap:wrap;align-items:end;gap:14px 22px;margin-bottom:18px;display:flex}label{color:var(--muted);flex-direction:column;gap:5px;font-size:14px;display:flex}button,select{font:inherit;color:var(--ink);background:var(--panel);border:1px solid var(--line);cursor:pointer;border-radius:6px;padding:7px 10px;font-size:15px}button:focus-visible,input:focus-visible,select:focus-visible{outline:2px solid var(--accent);outline-offset:2px}button{padding:8px 14px}button:disabled{opacity:.5;cursor:default}.primary{background:var(--ink);color:var(--bg);border-color:var(--ink)}.check{color:var(--ink);flex-direction:row;align-items:center;gap:8px;padding-bottom:9px}.check input{width:16px;height:16px;accent-color:var(--accent);margin:0}.stage{background:var(--panel);border:1px solid var(--line);border-radius:10px;padding:18px}.stage canvas{width:100%;max-width:720px;height:auto;image-rendering:pixelated;image-rendering:crisp-edges;margin:0 auto;display:block}.caption{flex-wrap:wrap;justify-content:space-between;gap:12px;margin-top:12px;font-size:15px;display:flex}.caption .name{font-size:18px;font-weight:700}.caption .name.hidden{color:var(--muted);font-weight:400}.caption .cells,h2{color:var(--muted)}h2{margin:28px 0 10px;font-size:16px;font-weight:500}.ladder{gap:10px;padding:6px 2px 10px;display:flex;overflow-x:auto}.ladder button{background:0 0;border:2px solid #0000;border-radius:6px;flex-direction:column;flex:none;align-items:center;gap:4px;padding:0;display:flex}.ladder button.active{border-color:var(--accent)}.ladder canvas{width:96px;height:72px;image-rendering:pixelated;border-radius:3px;display:block}.ladder span{color:var(--muted);padding-bottom:4px;font-size:12px}.hint{margin-top:14px}.hint,footer{color:var(--muted);font-size:13px}footer{border-top:1px solid var(--line);max-width:70ch;margin-top:36px;padding-top:14px}footer a{color:var(--ink)}.scoreboard{flex-wrap:wrap;justify-content:space-between;gap:12px;margin-bottom:12px;font-size:15px;display:flex}.scoreboard strong{font-size:18px}.tag{color:var(--muted);border:1px solid var(--line);vertical-align:middle;border-radius:999px;margin-left:8px;padding:1px 9px;font-size:13px;display:inline-block}.round-actions{flex-wrap:wrap;align-items:center;gap:10px;margin-top:14px;display:flex}.worth{color:var(--muted);margin-left:auto;font-size:14px}.choices{grid-template-columns:repeat(2,1fr);gap:10px;margin-top:16px;display:grid}@media (width>=560px){.choices.six{grid-template-columns:repeat(3,1fr)}}.choices button{text-align:left;padding:12px 14px;font-size:16px}.choices button.wrong{background:var(--bad-bg);border-color:var(--bad);color:var(--bad);text-decoration:line-through}.choices button.right{background:var(--good-bg);border-color:var(--good);color:var(--good);font-weight:700}.result{min-height:1.5em;margin-top:14px;font-size:16px}.result.good{color:var(--good)}.result.bad{color:var(--bad)}.summary{text-align:center;padding:24px 0}.summary .big{font-size:48px;font-weight:700;line-height:1.1}.summary p{color:var(--muted);margin:6px 0 18px}.history{text-align:left;grid-template-columns:repeat(auto-fill,minmax(150px,1fr));gap:8px;margin:0 0 20px;padding:0;font-size:14px;list-style:none;display:grid}.history li{background:var(--panel);border:1px solid var(--line);border-radius:6px;justify-content:space-between;padding:6px 10px;display:flex}.history li span:last-child{color:var(--muted)}@media (prefers-reduced-motion:no-preference){.choices button,.ladder button{transition:border-color .12s,background .12s}}