:root{--bg: #0b1220;--panel: #121d2f;--line: #2a3c56;--ink: #e2e9f4;--dim: #90a2bd;--accent: #f2b880;--loop: #4cc9f0;--open: #3d5273;--cross: #55688a;--good: #6fd3a8;--bad: #f87171;--inside: #f6f8fc;--outside: #0e1826}*{box-sizing:border-box}body{margin:0;background:radial-gradient(1200px 600px at 50% -10%,#16273f 0%,var(--bg) 60%);color:var(--ink);font-family:ui-sans-serif,system-ui,-apple-system,Helvetica Neue,sans-serif;line-height:1.65}main{max-width:900px;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(--loop)}.sub{color:var(--dim);margin:0 0 1.4rem;font-size:.95rem}.sub strong{color:var(--ink)}.sub em{color:var(--accent);font-style:italic}#wrap{display:flex;gap:22px;align-items:flex-start;flex-wrap:wrap;justify-content:center}h3{font-size:.75rem;text-transform:uppercase;letter-spacing:.12em;color:var(--dim);margin:0 0 8px;font-weight:600}.stage{flex:0 0 auto}#boardwrap{padding:14px;background:var(--panel);border:1px solid var(--line);border-radius:12px;display:inline-block;line-height:0}#board{touch-action:manipulation;-webkit-user-select:none;user-select:none}#board .grid{stroke:#1d2b42;stroke-width:1}#board .dot{fill:#27374f}#board .hit{stroke:transparent;stroke-width:15;stroke-linecap:round;cursor:pointer}#board .hit:hover{stroke:#4cc9f029}#board .seg{stroke:var(--loop);stroke-width:6;stroke-linecap:round;pointer-events:none}#board .seg.given{stroke:var(--open)}#board .cross{stroke:var(--cross);stroke-width:2.4;stroke-linecap:round;pointer-events:none}#board .open{stroke:#f2b88080;stroke-width:2;stroke-dasharray:3 4;pointer-events:none}#board .hintseg{stroke:var(--accent);stroke-width:9;stroke-linecap:round;opacity:.55;pointer-events:none}#board .wall{stroke-width:1.6}#board .wall.white{fill:var(--inside);stroke:#0b1220}#board .wall.black{fill:var(--outside);stroke:#66799a}#board .wall.grey{fill:#46566e;stroke:#7387a3}#board text{font-family:ui-sans-serif,system-ui,sans-serif;font-size:15px;font-weight:700;font-variant-numeric:tabular-nums;text-anchor:middle;dominant-baseline:central;pointer-events:none}#board text.on-white{fill:#0b1220}#board text.on-black,#board text.on-grey{fill:#f2f6fc}.side{flex:1 1 280px;min-width:260px;max-width:340px}.panel{background:var(--panel);border:1px solid var(--line);border-radius:12px;padding:12px 14px;font-size:.86rem}.panel .row{display:flex;justify-content:space-between;gap:10px;padding:3px 0;color:var(--dim)}.panel .row b{color:var(--ink);font-variant-numeric:tabular-nums;font-weight:600}.legend{margin-top:12px;font-size:.8rem;color:var(--dim)}.legend span{display:inline-flex;align-items:center;gap:6px;margin-right:12px}.swatch{width:14px;height:14px;border-radius:3px;display:inline-block}.swatch.white{background:var(--inside);border:1px solid #0b1220}.swatch.black{background:var(--outside);border:1px solid #66799a}.swatch.grey{background:#46566e;border:1px solid #7387a3}#status{margin-top:12px;min-height:3.4em;font-size:.88rem;color:var(--dim)}#status .win{color:var(--good)}#status .err{color:var(--bad)}.controls{margin-top:18px;display:flex;flex-wrap:wrap;gap:8px;align-items:center}label.sel,label.chk{display:flex;align-items:center;gap:6px;font-size:.8rem;color:var(--dim)}select,button{font:inherit;font-size:.85rem;background:var(--panel);color:var(--ink);border:1px solid var(--line);border-radius:8px;padding:6px 12px;cursor:pointer}button:hover,select:hover{border-color:var(--loop)}.notes{margin-top:2.6rem;font-size:.93rem}.notes h2{font-size:1.15rem;margin:2rem 0 .6rem;letter-spacing:-.01em}.notes p{color:#c4d1e4}.notes strong{color:var(--ink)}.notes em{color:var(--accent);font-style:normal}.notes table{border-collapse:collapse;width:100%;margin:.9rem 0 1.4rem;font-size:.85rem;font-variant-numeric:tabular-nums}.notes th,.notes td{border:1px solid var(--line);padding:5px 9px;text-align:right}.notes tr>th:first-child,.notes tr>td:first-child{text-align:left}.notes tr:first-child th{background:#16233a;color:var(--dim);font-weight:600;text-align:left}.notes pre{background:#0d1625;border:1px solid var(--line);border-radius:8px;padding:10px 12px;overflow-x:auto;font-size:.8rem;line-height:1.5;color:#c4d1e4}.notes a{color:var(--loop)}footer{margin-top:3rem;padding-top:1.2rem;border-top:1px solid var(--line);color:var(--dim);font-size:.82rem}footer a{color:var(--loop)}