:root{color-scheme:light;--paper:#f6f4eb;--ink:#253930;--muted:#65766b;--accent:#416d4f;--line:#d8dfd3;--soft:#edf0e6;font-family:Inter,ui-sans-serif,system-ui,-apple-system,BlinkMacSystemFont,"Segoe UI",sans-serif}*{box-sizing:border-box}body{margin:0;background:var(--paper);color:var(--ink)}[hidden]{display:none!important}a{color:inherit;text-underline-offset:4px}button,select{font:inherit}button{cursor:pointer}button:disabled{cursor:default;opacity:.45}button,select,a{touch-action:manipulation}button:focus-visible,select:focus-visible,a:focus-visible,summary:focus-visible{outline:3px solid #d57b3e;outline-offset:4px}.skip{position:absolute;left:12px;top:-80px;z-index:5;background:white;padding:12px}.skip:focus{top:12px}header,main,footer{max-width:1080px;margin:auto;padding:0 28px}header{height:92px;display:flex;align-items:center;justify-content:space-between;gap:16px}header>a:last-child{font-size:13px}.brand{display:flex;align-items:center;gap:10px;font-weight:750;font-size:20px;letter-spacing:-.7px;text-decoration:none}.brand svg{width:34px;height:34px}.heading{padding:24px 0 28px;display:flex;align-items:center;justify-content:space-between;gap:20px}.heading h1{font-family:Georgia,serif;font-size:clamp(32px,5vw,50px);font-weight:500;letter-spacing:-1.5px;margin:0 0 10px}.heading p{max-width:500px;color:var(--muted);margin:0;font-size:15px;line-height:1.6}.heading-mark{width:100px;height:100px;color:var(--accent);transform:rotate(-12deg)}.play-layout{display:grid;grid-template-columns:minmax(0,1fr) 244px;gap:22px;align-items:start}.stage{min-width:0;background:#fffdfa;border:1px solid var(--line);border-radius:24px;box-shadow:0 16px 44px #35473308;padding:20px}.stage-top{display:flex;justify-content:space-between;gap:12px;align-items:center;font-size:12px;color:var(--muted);margin-bottom:18px}.stage-top span:first-child{color:var(--ink);font-weight:700}.score-head{display:flex;justify-content:center;gap:12px;margin-bottom:20px}.score-pill{display:flex;align-items:center;justify-content:space-between;gap:12px;min-width:0;width:180px;padding:10px 14px;background:var(--soft);border-radius:14px;font-size:12px}.score-value{font-size:22px;font-weight:800;font-variant-numeric:tabular-nums}.score-dot{width:12px;height:12px;flex:none;border-radius:50%;background:#25352f}.score-pill.second .score-dot{background:#f7f3e5;border:1px solid #a3afa2}.score-label{flex:1}.key-note{color:var(--muted);font-size:11px;text-align:center;line-height:1.5;margin:14px 0 0}.rail{min-width:0}.feedback{font-size:15px;line-height:1.6;min-height:60px;margin:0 0 16px;padding:4px 0;color:var(--ink)}.actions{display:grid;grid-template-columns:repeat(3,minmax(0,1fr));gap:6px}.actions button,.quiet{background:transparent;border:1px solid var(--line);border-radius:10px;min-height:44px;padding:8px;font-size:12px;color:var(--ink)}.settings{border-top:1px solid var(--line);padding-top:22px;margin-top:24px}.settings h2{font-size:14px;margin:0 0 14px}.settings label{display:block;font-size:12px;color:var(--muted);margin-bottom:12px}.settings select{display:block;width:100%;min-height:44px;background:#fffdf8;color:var(--ink);border:1px solid var(--line);padding:8px;border-radius:9px;margin-top:5px}.primary{background:var(--accent);color:white;min-height:46px;padding:10px 16px;border:0;border-radius:10px;font-size:13px;font-weight:700;width:100%}.result{padding:18px;background:var(--soft);border-radius:16px;margin-bottom:16px}.result h2{font-family:Georgia,serif;font-size:25px;font-weight:500;margin:0 0 5px}.result p{font-size:21px;font-weight:700;margin:0 0 14px}.saved-note{font-size:11px;color:var(--muted);line-height:1.6;margin:16px 0 0}.notice{border:1px solid #caab75;background:#fff8e8;border-radius:14px;padding:14px;margin:0 0 18px;font-size:13px;line-height:1.5}.notice p{margin:0 0 12px}.notice button{min-height:44px;border:1px solid #ba9d6a;background:#fffcf6;border-radius:8px;padding:8px 12px;color:#574329}details{margin-top:10px}summary{cursor:pointer;min-height:36px;display:flex;align-items:center;font-size:12px}pre{white-space:pre-wrap;overflow-wrap:anywhere;font-size:11px;line-height:1.5}.steps{padding:25px 0 28px;list-style:none;display:grid;grid-template-columns:repeat(3,minmax(0,1fr));gap:20px;margin:0}.steps li{display:flex;gap:10px}.steps span{color:var(--accent);font-size:12px;padding-top:3px;font-variant-numeric:tabular-nums}.steps p{font-size:13px;line-height:1.6;margin:0;color:var(--muted)}footer{border-top:1px solid var(--line);padding-top:24px;padding-bottom:28px;display:flex;justify-content:space-between;gap:16px;align-items:center;font-size:12px;color:var(--muted)}footer nav{display:flex;gap:20px}dialog{width:min(440px,calc(100% - 32px));border:1px solid var(--line);border-radius:20px;padding:25px;background:var(--paper);color:var(--ink);box-shadow:0 30px 100px #16261c44}dialog::backdrop{background:#1a281c66}dialog h2{font-family:Georgia,serif;font-size:26px;font-weight:500;margin:0 0 12px}dialog p{font-size:14px;line-height:1.6}.dialog-actions{display:flex;gap:10px;justify-content:flex-end}.dialog-actions .primary{width:auto}.doc{max-width:720px;padding-top:20px;padding-bottom:48px}.doc h1{font-family:Georgia,serif;font-size:40px;font-weight:500;letter-spacing:-1px;margin:10px 0 25px}.doc h2{font-size:19px;margin:28px 0 10px}.doc p,.doc li{font-size:15px;line-height:1.8;color:var(--muted)}.doc ol,.doc ul{padding-left:24px}.doc .primary{display:inline-flex;align-items:center;justify-content:center;width:auto;text-decoration:none;margin-top:20px}.rule-source{font-size:12px!important}.doc code{font:inherit;color:var(--ink)}
@media(max-width:820px){.play-layout{grid-template-columns:minmax(0,1fr) 210px;gap:16px}header,main,footer{padding-left:20px;padding-right:20px}.stage{padding:14px}.heading-mark{width:74px;height:74px}.score-pill{padding:9px 10px;font-size:11px}}
@media(max-width:650px){header{height:72px}.heading{padding:20px 0 24px}.heading-mark{width:60px;height:60px}.heading p{font-size:13px}.play-layout{grid-template-columns:1fr}.rail{display:grid;grid-template-columns:1fr 1fr;gap:0 18px}.rail .feedback,.rail .actions,.rail .saved-note,.rail .notice,.rail .result{grid-column:1/-1}.settings{grid-column:1/-1;display:grid;grid-template-columns:1fr 1fr;gap:0 10px}.settings h2,.settings .primary{grid-column:1/-1}.settings label{min-width:0}.settings select{font-size:12px}.feedback{min-height:0;margin:3px 0 14px}.steps{gap:12px}.steps li{display:block}.steps p{font-size:12px}.steps span{display:block;margin-bottom:5px}.doc h1{font-size:34px}footer nav{gap:12px}.score-head{margin-bottom:15px}.key-note{font-size:10px}}
@media(max-width:380px){header,main,footer{padding-left:12px;padding-right:12px}.heading-mark{display:none}.heading h1{font-size:33px}.brand{font-size:18px}.brand svg{width:29px;height:29px}.stage{padding:10px;border-radius:18px}.stage-top{font-size:10px;gap:7px;margin-bottom:12px}.score-pill{padding:8px;font-size:10px;gap:6px}.score-value{font-size:20px}.score-head{gap:8px}.steps{gap:9px}footer{align-items:flex-start;line-height:1.8}footer nav{flex-wrap:wrap;justify-content:flex-end}}
@media(prefers-reduced-motion:reduce){*{scroll-behavior:auto!important;transition:none!important}}
#board{display:grid;grid-template-columns:repeat(8,minmax(0,1fr));gap:2px;padding:7px;max-width:536px;width:100%;margin:auto;background:#1b4634;border:1px solid #1b4634;border-radius:12px;box-shadow:0 10px 22px #193b2b15}.square{position:relative;aspect-ratio:1;border:0;background:#53836a;display:grid;place-items:center;padding:5px;min-width:0;border-radius:2px}.square:nth-child(16n+1),.square:nth-child(16n+3),.square:nth-child(16n+5),.square:nth-child(16n+7),.square:nth-child(16n+10),.square:nth-child(16n+12),.square:nth-child(16n+14),.square:nth-child(16n+16){background:#5b8b71}.disc{display:block;border-radius:50%;width:88%;height:88%;pointer-events:none}.black .disc{background:radial-gradient(circle at 35% 25%,#46564b,#1d2924 65%,#14251d);box-shadow:0 3px 4px #142b2859,inset 0 0 0 1px #142b2850}.white .disc{background:radial-gradient(circle at 35% 25%,#fffef2,#eee9d7 65%,#d7dccb);box-shadow:0 3px 4px #142b2859,inset 0 0 0 1px #fffff077}.empty.available .disc{width:24%;height:24%;background:#e9f3d270;box-shadow:none}.empty.available:hover .disc{width:64%;height:64%;background:#ddecc680}.square.last::after{content:"";position:absolute;inset:43%;background:#c89759;border-radius:50%}.square.hint{outline:3px solid #f1cf83;outline-offset:-3px}.square:focus-visible{outline:3px solid #ffe2a4;outline-offset:-3px;z-index:1}.board-frame{max-width:565px;margin:auto}.board-coordinates{display:grid;grid-template-columns:repeat(8,1fr);gap:2px;padding:0 8px 8px;color:var(--muted);font-size:10px;text-align:center}.square[aria-disabled="true"]{cursor:default}.heading-mark circle:nth-child(2){fill:#e4e8d5}.heading-mark circle:nth-child(3){fill:#304837}@media(max-width:380px){#board{padding:5px;gap:2px;border-radius:8px}.square{padding:3px}.board-coordinates{font-size:9px;padding-bottom:6px}}