:root{--bg: #f6f8fa;--surface: #ffffff;--surface-2: #eef1f4;--text: #1b1f24;--text-dim: #57606a;--border: #d0d7de;--grid-line: #9aa5b1;--grid-line-strong: #4b5563;--accent: #1f6feb;--accent-contrast: #ffffff;--given: #1b1f24;--entered: #1f6feb;--hl-peer: rgba(31, 111, 235, .1);--hl-same: rgba(255, 196, 0, .28);--hl-hint: #2f9e44;--conflict: #d1242f;color-scheme:light dark;font-family:system-ui,-apple-system,Segoe UI,Roboto,sans-serif;line-height:1.5}@media (prefers-color-scheme: dark){:root{--bg: #0d1117;--surface: #161b22;--surface-2: #21262d;--text: #f0f6fc;--text-dim: #adbac7;--border: #3d444d;--grid-line: #586069;--grid-line-strong: #adbac7;--given: #f0f6fc;--entered: #6cb6ff;--hl-peer: rgba(88, 166, 255, .2);--hl-same: rgba(255, 196, 0, .32);--hl-hint: #3fb950;--conflict: #ff7b72}}[data-theme=light]{--bg: #f6f8fa;--surface: #fff;--surface-2: #eef1f4;--text: #1b1f24;--text-dim: #57606a;--border: #d0d7de;--grid-line: #9aa5b1;--grid-line-strong: #4b5563;--given: #1b1f24;--entered: #1f6feb;--hl-peer: rgba(31,111,235,.1);--hl-same: rgba(255,196,0,.28);--hl-hint: #2f9e44;--conflict: #d1242f}[data-theme=dark]{--bg: #0d1117;--surface: #161b22;--surface-2: #21262d;--text: #f0f6fc;--text-dim: #adbac7;--border: #3d444d;--grid-line: #586069;--grid-line-strong: #adbac7;--given: #f0f6fc;--entered: #6cb6ff;--hl-peer: rgba(88,166,255,.2);--hl-same: rgba(255,196,0,.32);--hl-hint: #3fb950;--conflict: #ff7b72}*{box-sizing:border-box}body{margin:0;min-height:100vh;background:var(--bg);color:var(--text)}button{font:inherit;cursor:pointer}h1{font-size:1.4rem}h2{font-size:1.1rem}.app{min-height:100vh;display:flex;flex-direction:column}.app-bar{display:flex;justify-content:space-between;align-items:center;padding:.6rem 1rem;border-bottom:1px solid var(--border);background:var(--surface)}.brand{font-weight:700}.app-main{flex:1;width:100%;max-width:560px;margin:0 auto;padding:1rem 1rem 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.5rem;color:var(--conflict);font-weight:600}.timer{display:inline-flex;gap:.4rem;align-items:center;background:var(--surface-2);border:1px solid var(--border);border-radius:8px;padding:.3rem .6rem;font-variant-numeric:tabular-nums;color:var(--text)}.board-wrap{position:relative}@media (orientation: landscape) and (min-width: 700px){.app-main{max-width:960px}.play-body{display:flex;align-items:flex-start;gap:1.2rem}.board-col{flex:0 0 auto;width:min(60vh,52vw)}.play-side{flex:1 1 0;min-width:200px}.play-side>:first-child{margin-top:0}}.board{display:grid;grid-template-columns:repeat(9,1fr);aspect-ratio:1;border:3px solid 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transparent}.diff-tab.active{color:var(--text);font-weight:700}.diff-tab.easy.active{border-bottom-color:#2f9e44}.diff-tab.medium.active{border-bottom-color:#1f6feb}.diff-tab.hard.active{border-bottom-color:#d97706}.diff-tab.expert.active{border-bottom-color:#d1242f}.level-grid{display:grid;grid-template-columns:1fr 1fr;gap:.8rem;margin-top:1rem}.level-card{padding:1.6rem 1rem;border-radius:12px;border:1px solid var(--border);background:var(--surface);color:var(--text);font-size:1.1rem;text-transform:capitalize}.level-card.easy{border-left:5px solid #2f9e44}.level-card.medium{border-left:5px solid #1f6feb}.level-card.hard{border-left:5px solid #d97706}.level-card.expert{border-left:5px solid #d1242f}.sub{color:var(--text-dim)}table{width:100%;border-collapse:collapse;margin-top:1rem}th,td{text-align:left;padding:.5rem .4rem;border-bottom:1px solid var(--border)}th{color:var(--text-dim);font-weight:600;font-size:.8rem}tr.me{background:var(--hl-peer);font-weight:700}td.diff-tag{text-transform:capitalize}.stat-cards{display:grid;grid-template-columns:repeat(2,1fr);gap:.8rem;margin-top:1rem}.stat-card{background:var(--surface);border:1px solid var(--border);border-radius:12px;padding:1rem;display:flex;flex-direction:column;gap:.2rem}.stat-num{font-size:1.8rem;font-weight:700;color:var(--accent)}.stat-label{color:var(--text-dim);font-size:.85rem}.settings .row{display:flex;justify-content:space-between;align-items:center;gap:1rem;padding:.8rem 0;border-bottom:1px solid var(--border)}.settings select{padding:.4rem;border-radius:6px;border:1px solid var(--border);background:var(--surface);color:var(--text)}.settings input[type=checkbox]{width:1.3rem;height:1.3rem;accent-color:var(--accent)}.settings-version{margin-top:1.5rem;text-align:center;color:var(--text-dim);font-size:.8rem}