:root{--bg: #f5f5f5;--panel-bg: #ffffff;--text: #1a1a2e;--text-muted: #555;--border-thin-w: 1px;--border-thick-w: 3px;--border-color: #aaa;--border-thick-color: #333;--select-border: #bbb;--color-given: #1a1a2e;--color-user: #1565c0;--color-selected: #bbdefb;--color-highlighted: #e3f2fd;--color-error: #ffcdd2;--color-error-text: #c62828;--note-color: #666;--shade-main: rgba(100, 180, 255, .18);--shade-anti: rgba(255, 150, 80, .18);--shade-both: rgba(120, 210, 120, .18);--accent: #1565c0;--accent-text: #fff;--btn-secondary-bg: #e0e0e0;--btn-secondary-text: #333;--btn-active-bg: #ffa000;--ok-bg: #e8f5e9;--ok-border: #4caf50;--ok-text: #2e7d32;--err-bg: #ffebee;--err-border: #ef9a9a;--err-text: #c62828;--pad-border: #ddd;--pad-hover: #e3f2fd;--spinner-track: #ddd;--shadow: rgba(0, 0, 0, .15);color-scheme:light}@media(prefers-color-scheme:dark){:root{--bg: #15171c;--panel-bg: #1f232b;--text: #e8e9ee;--text-muted: #a0a4ad;--border-color: #4a4f5a;--border-thick-color: #c9ccd4;--select-border: #4a4f5a;--color-given: #f2f3f7;--color-user: #7fb3ff;--color-selected: #2d4d7a;--color-highlighted: #262f3f;--color-error: #5a2a2e;--color-error-text: #ff8a80;--note-color: #b0b4bd;--shade-main: rgba(100, 180, 255, .16);--shade-anti: rgba(255, 150, 80, .16);--shade-both: rgba(120, 210, 120, .16);--accent: #4f8fe0;--accent-text: #fff;--btn-secondary-bg: #2e333d;--btn-secondary-text: #e8e9ee;--btn-active-bg: #d98a00;--ok-bg: #1d3323;--ok-border: #3f9a48;--ok-text: #9be3a3;--err-bg: #3a2124;--err-border: #a04a4a;--err-text: #ff9a90;--pad-border: #3a3f4a;--pad-hover: #262f3f;--spinner-track: #3a3f4a;--shadow: rgba(0, 0, 0, .5);color-scheme:dark}}*{box-sizing:border-box;margin:0;padding:0}html,body,#root{min-height:100%}body{background:var(--bg);color:var(--text);font-family:Hiragino Sans,Yu Gothic,Segoe UI,system-ui,-apple-system,sans-serif;font-size:16px;-webkit-font-smoothing:antialiased;padding:24px 16px 48px}.app{display:flex;flex-direction:column;align-items:center;gap:18px;width:100%;max-width:600px;margin:0 auto}.title{font-size:2rem;font-weight:700;letter-spacing:.06em}.key-help{font-size:.8rem;color:var(--text-muted);text-align:center}.mode-tab-bar{display:flex;gap:8px}.mode-tab-bar .btn{min-width:100px;min-height:44px}.controls{display:flex;gap:10px;flex-wrap:wrap;justify-content:center;align-items:center}.puzzle-type-select{padding:8px 12px;min-height:44px;border:2px solid var(--select-border);border-radius:8px;font-size:.95rem;background:var(--panel-bg);color:var(--text);cursor:pointer}.btn{padding:8px 18px;min-height:44px;border:none;border-radius:8px;font-size:.95rem;font-weight:600;cursor:pointer;transition:opacity .15s,transform .1s}.btn:hover:not(:disabled){opacity:.85;transform:translateY(-1px)}.btn:disabled{opacity:.45;cursor:default}.btn-primary{background:var(--accent);color:var(--accent-text)}.btn-secondary{background:var(--btn-secondary-bg);color:var(--btn-secondary-text)}.btn-active{background:var(--btn-active-bg);color:#fff}.difficulty-badge{font-size:.9rem;font-weight:600;color:var(--text-muted);letter-spacing:.03em}.status-banner{background:var(--ok-bg);border:2px solid var(--ok-border);color:var(--ok-text);border-radius:10px;padding:10px 24px;font-size:1.1rem;font-weight:700}.error-banner{background:var(--err-bg);border:2px solid var(--err-border);color:var(--err-text);border-radius:10px;padding:10px 24px;font-size:1rem;font-weight:600;text-align:center}.info-bar{min-height:50px;display:flex;align-items:center;justify-content:center}.loading-overlay{display:flex;flex-direction:column;align-items:center;gap:6px;color:var(--text-muted);font-size:.85rem}.spinner{width:26px;height:26px;border:3px solid var(--spinner-track);border-top-color:var(--accent);border-radius:50%;animation:spin .8s linear infinite}@keyframes spin{to{transform:rotate(360deg)}}.board-wrapper{display:flex;flex-direction:column;align-items:center;gap:18px;width:100%}.board{display:grid;border:3px solid var(--border-thick-color);border-radius:4px;overflow:hidden;box-shadow:0 4px 20px var(--shadow);background:var(--panel-bg)}.sudoku-cell{display:flex;align-items:center;justify-content:center;border-style:solid;border-color:var(--border-color);cursor:pointer;position:relative;user-select:none;transition:background .08s}.sudoku-cell.shade-main{background:var(--shade-main)}.sudoku-cell.shade-anti{background:var(--shade-anti)}.sudoku-cell.shade-both{background:var(--shade-both)}.sudoku-cell.highlighted{background:var(--color-highlighted)}.sudoku-cell.error{background:var(--color-error)}.sudoku-cell.selected{background:var(--color-selected)}@media(pointer:coarse){.sudoku-cell:after{content:"";position:absolute;top:50%;left:50%;transform:translate(-50%,-50%);min-width:44px;min-height:44px;width:100%;height:100%}}.cell-value{font-weight:700;color:var(--color-user);line-height:1}.cell-large .cell-value{font-size:1.4rem}.cell-small .cell-value{font-size:.9rem}.sudoku-cell.given .cell-value{color:var(--color-given)}.sudoku-cell.error .cell-value{color:var(--color-error-text)}.notes-grid{display:grid;width:100%;height:100%;padding:2px}.note-num{display:flex;align-items:center;justify-content:center;color:var(--note-color);font-weight:600;line-height:1}.cell-large .note-num{font-size:.58rem}.cell-small .note-num{font-size:.42rem}.number-pad{display:grid;gap:7px;width:100%}.pad-btn{height:46px;border:2px solid var(--pad-border);border-radius:10px;background:var(--panel-bg);font-size:1.2rem;font-weight:700;color:var(--color-user);cursor:pointer;transition:background .1s,transform .1s;box-shadow:0 2px 4px var(--shadow)}.pad-btn:hover{background:var(--pad-hover);transform:translateY(-2px)}.pad-btn:active{transform:translateY(0)}.pad-btn-clear{font-size:.95rem;color:var(--err-text);border-color:var(--err-border)}.pad-btn-clear:hover{background:var(--err-bg)}