:root{--bg: #14161a;--surface: #1d2128;--surface-2: #262b34;--text: #e6e8ec;--muted: #9aa3af;--line: #3a414d;--line-strong: #aeb6c2;--accent: #6ea8fe;--given: #f2f4f7;--entry: #6ea8fe;--error-bg: #5a1f27;--error-text: #ff9aa6;--sel: #2f4b73;--radius: 10px}@media(prefers-color-scheme:light){:root{--bg: #f5f6f8;--surface: #ffffff;--surface-2: #eef1f5;--text: #1a1d22;--muted: #5b6573;--line: #c8ced6;--line-strong: #2a2f37;--given: #1a1d22;--entry: #1c5fd6;--error-bg: #ffe1e4;--error-text: #b3261e;--sel: #cfe0ff}}*{box-sizing:border-box}body{margin:0;background:var(--bg);color:var(--text);font-family:system-ui,-apple-system,Segoe UI,Roboto,Helvetica,Arial,sans-serif;line-height:1.5}.app{max-width:640px;margin:0 auto;padding:1.25rem 1rem 3rem}.app-head h1{margin:0;font-size:2rem;letter-spacing:-.01em}.tagline{margin:.25rem 0 1.25rem;color:var(--muted)}a{color:var(--accent)}.app-controls,.app-toolbar{display:flex;flex-wrap:wrap;align-items:center;gap:.75rem;margin-bottom:1rem}.control{display:flex;flex-direction:column;gap:.2rem;font-size:.85rem;color:var(--muted)}.control-diff{flex:1 1 180px;min-width:180px}.control-diff input[type=range]{width:100%;accent-color:var(--accent)}select,button{font:inherit;color:var(--text);background:var(--surface-2);border:1px solid var(--line);border-radius:8px;padding:.45rem .7rem;cursor:pointer}button:hover,select:hover{border-color:var(--line-strong)}button.primary{background:var(--accent);border-color:var(--accent);color:#07111f;font-weight:600;align-self:end}.toggle{display:inline-flex;align-items:center;gap:.4rem;cursor:pointer;-webkit-user-select:none;user-select:none}.toggle input{accent-color:var(--accent)}.spacer{flex:1}.board{display:grid;grid-template-columns:repeat(var(--n, 6),1fr);gap:0;width:100%;aspect-ratio:1;margin:0 auto 1rem;border:3px solid var(--line-strong);border-radius:4px;overflow:hidden;-webkit-user-select:none;user-select:none}.board.busy{opacity:.5;pointer-events:none}.cell{position:relative;display:flex;align-items:center;justify-content:center;background:var(--surface);border:1px solid var(--line);cursor:pointer;aspect-ratio:1;font-size:clamp(1rem,6vw,2rem);font-weight:600}.cell.b-top{border-top:2.5px solid var(--line-strong)}.cell.b-bottom{border-bottom:2.5px solid var(--line-strong)}.cell.b-left{border-left:2.5px solid var(--line-strong)}.cell.b-right{border-right:2.5px solid var(--line-strong)}.cell.selected{background:var(--sel)}.cell.given .value{color:var(--given)}.cell .value{color:var(--entry)}.cell.error{background:var(--error-bg)}.cell.error .value{color:var(--error-text)}.pencils{display:grid;grid-template-columns:repeat(3,1fr);width:100%;height:100%;padding:2px;font-size:clamp(.5rem,2.4vw,.8rem);font-weight:500;color:var(--muted);line-height:1}.pencils span{display:flex;align-items:center;justify-content:center}.status{min-height:1.5rem;margin:0 0 1rem;text-align:center;font-weight:600}.status.solved{color:#45c267;font-size:1.2rem}.numpad{display:grid;grid-template-columns:repeat(5,1fr);gap:.5rem;margin-bottom:1.5rem}.numpad button{padding:.7rem 0;font-size:1.1rem;font-weight:600}.numpad button:disabled{opacity:.35;cursor:not-allowed}.numpad .erase{grid-column:span 5;font-size:.95rem}@media(min-width:480px){.numpad .erase{grid-column:auto}}.rules{background:var(--surface);border:1px solid var(--line);border-radius:var(--radius);padding:.5rem 1.25rem 1rem}.rules h2{font-size:1.1rem}.rules .hint{color:var(--muted);font-size:.9rem}kbd{background:var(--surface-2);border:1px solid var(--line);border-radius:4px;padding:0 .35em;font-family:ui-monospace,monospace;font-size:.85em}.app-foot{margin-top:2rem;text-align:center;color:var(--muted);font-size:.9rem}@media print{:root{--bg: #fff;--surface: #fff;--text: #000;--given: #000;--entry: #000;--line: #999;--line-strong: #000}body{background:#fff}.app-controls,.app-toolbar,.numpad,.status,.app-foot,.tagline{display:none!important}.board{max-width:16cm;page-break-inside:avoid}.cell .value{color:#000!important}}