:root{--bg: #0d1117;--panel: #161d26;--ink: #e8eef5;--muted: #8fa3b8;--board-edge: rgba(56, 189, 248, .18);--cellbg: #1b2330;--accent: #38bdf8;--shade: #0e7490;--shade-lit: #22d3ee;--wall: rgba(56, 189, 248, .75);--good: #4ade80;--bad: #f87171;--hintc: #fbbf24;--cell: 54px}*{box-sizing:border-box}html,body{margin:0;min-height:100%;background:radial-gradient(1100px 640px at 50% -8%,#14263a 0%,var(--bg) 60%);color:var(--ink);font:15px/1.5 ui-sans-serif,system-ui,-apple-system,Segoe UI,Roboto,sans-serif}main{max-width:720px;margin:0 auto;padding:32px 20px 48px;text-align:center}h1{margin:0;font-size:34px;letter-spacing:.5px}h1 span{color:var(--accent);text-shadow:0 0 18px rgba(56,189,248,.45)}.sub{margin:6px auto 20px;max-width:610px;color:var(--muted)}.sub strong,.note strong{color:var(--ink)}#wrap{display:flex;justify-content:center}#board{display:grid;padding:16px;background:var(--panel);border:1px solid var(--board-edge);border-radius:14px;position:relative;gap:0}.badge{position:absolute;top:-9px;right:14px;font-size:11px;letter-spacing:.6px;text-transform:uppercase;color:var(--muted);background:var(--bg);padding:0 8px;border-radius:6px}.cell{width:var(--cell);height:var(--cell);border:1px solid rgba(143,163,184,.16);border-radius:0;background:var(--cellbg);cursor:pointer;padding:0;position:relative;color:var(--ink);font:inherit;transition:background .12s,box-shadow .12s}.cell:hover{z-index:3;box-shadow:inset 0 0 0 2px #38bdf873}.cell.wall-t{border-top:2px solid var(--wall)}.cell.wall-b{border-bottom:2px solid var(--wall)}.cell.wall-l{border-left:2px solid var(--wall)}.cell.wall-r{border-right:2px solid var(--wall)}.cell.shaded{background:var(--shade);box-shadow:inset 0 0 0 1px #22d3ee8c}.cell.white:after{content:"";position:absolute;left:50%;top:50%;width:7px;height:7px;margin:-3.5px 0 0 -3.5px;border-radius:50%;background:#8fa3b873}.num{position:absolute;top:2px;left:4px;font-size:15px;font-weight:700;line-height:1;color:var(--ink);text-shadow:0 1px 3px rgba(0,0,0,.8);pointer-events:none}.num.done{color:var(--good);opacity:.85}.num.bad{color:var(--bad)}.cell.conflict{box-shadow:inset 0 0 0 2px #f87171cc;z-index:2}.cell.hinted{box-shadow:inset 0 0 0 3px var(--hintc);z-index:4}#board.won .cell.shaded{background:#15803d;box-shadow:inset 0 0 0 1px #4ade8099}#board.won .cell.white:after{display:none}#board.won .cell{cursor:default}.hud{min-height:56px;margin:14px 0 4px}#status{color:var(--muted)}#status.good{color:var(--good)}#status.bad{color:var(--bad)}#status.hint{color:var(--hintc)}.controls{display:flex;flex-wrap:wrap;gap:10px;justify-content:center;align-items:center;margin-top:10px}.controls label{color:var(--muted);font-size:14px;display:flex;gap:6px;align-items:center}select,button{background:var(--panel);color:var(--ink);border:1px solid rgba(143,163,184,.35);border-radius:9px;padding:8px 16px;font-size:14px;cursor:pointer;transition:border-color .12s,box-shadow .12s}select:hover,button:hover{border-color:var(--accent);box-shadow:0 0 10px #38bdf840}.note{margin:34px auto 0;max-width:640px;text-align:left;color:var(--muted);font-size:14px;border-top:1px solid rgba(143,163,184,.18);padding-top:18px}.note table{border-collapse:collapse;margin:12px 0;font-size:13px}.note th,.note td{border:1px solid rgba(143,163,184,.2);padding:4px 10px;text-align:right}.note th:first-child,.note td:first-child{text-align:left}.note code{font-family:ui-monospace,SFMono-Regular,Menlo,monospace;font-size:12.5px;color:var(--accent)}@media (max-width: 560px){:root{--cell: 38px}.num{font-size:11px}}