:root{--bg: #0d1117;--panel: #131a23;--line: #263243;--ink: #dce3ec;--dim: #8a97a8;--accent: #a78bfa;--good: #7dd3a0;--bad: #f87171;--stone-black: #1b2330;--stone-white: #e8eef7}*{box-sizing:border-box}body{margin:0;background:var(--bg);color:var(--ink);font-family:ui-sans-serif,system-ui,-apple-system,Helvetica Neue,sans-serif;line-height:1.65}main{max-width:860px;margin:0 auto;padding:2.2rem 1.2rem 4rem}header h1{font-size:2.1rem;margin:0 0 .5rem;letter-spacing:-.02em}header h1 span{color:var(--accent)}.sub{color:var(--dim);margin:0 0 1.6rem;font-size:.95rem}.sub strong{color:var(--ink)}.legend{display:flex;flex-wrap:wrap;gap:.4rem 1.4rem;color:var(--dim);font-size:.85rem;margin-bottom:1.2rem}.legend i{display:inline-flex;width:18px;height:18px;border-radius:50%;vertical-align:-4px;margin-right:6px}.legend .black-demo{background:var(--stone-black);border:2px solid var(--dim)}.legend .white-demo{background:var(--stone-white);border:2px solid var(--dim)}.legend .given-demo{background:var(--stone-white);border:2px solid var(--accent)}.legend .bad-demo{background:transparent;border:2px solid var(--bad)}#wrap{overflow-x:auto;padding-bottom:.4rem}#stage{width:fit-content;margin:0 auto}#board{background:var(--panel);border:1px solid var(--line);border-radius:12px;padding:6px;line-height:0}#board.solved{border-color:var(--good);box-shadow:0 0 0 1px var(--good),0 0 24px #7dd3a040}#board svg{display:block}.cell{fill:transparent;stroke:var(--line);stroke-width:1;cursor:pointer}.cell:hover{fill:#a78bfa14}.cell.mono{fill:#f8717129}.front{stroke:var(--accent);stroke-width:3;stroke-linecap:round;pointer-events:none}#board.solved .front{stroke:var(--good)}.stone{stroke-width:2.25;cursor:pointer}.stone.black{fill:#0b0f16;stroke:#5d7290}.stone.white{fill:var(--stone-white);stroke:#b8c4d4}.stone.given{cursor:default}.stone.stranded{stroke:var(--bad);stroke-width:3}.pin{pointer-events:none}.pin.black{fill:#4a5a72}.pin.white{fill:#8a97a8}.hud{margin:.9rem 0 .6rem;min-height:1.6em;color:var(--dim);font-size:.92rem;text-align:center}.controls{display:flex;flex-wrap:wrap;gap:.6rem 1rem;align-items:end;justify-content:center;margin-bottom:2.2rem}.controls label{display:flex;flex-direction:column;gap:.25rem;color:var(--dim);font-size:.8rem}select,button{background:var(--panel);color:var(--ink);border:1px solid var(--line);border-radius:8px;padding:.45rem .8rem;font-size:.9rem;cursor:pointer}select:hover,button:hover,button#solve{border-color:var(--accent)}.notes{border-top:1px solid var(--line);padding-top:1.4rem;color:var(--dim);font-size:.95rem}.notes h2{color:var(--ink);font-size:1.15rem;margin:1.4rem 0 .4rem}.notes p{margin:0 0 .8rem}.notes strong{color:var(--ink)}.notes em{color:var(--ink);font-style:italic}footer{border-top:1px solid var(--line);margin-top:2rem;padding-top:1.2rem;color:var(--dim);font-size:.85rem}