:root{--bg: #ffffff;--fg: #111418;--muted: #6b7280;--cell-bg: #ffffff;--cell-fg: #111418;--cell-border: #d1d5db;--cage-border: #111418;--selected: #fde68a;--highlight: #fef3c7;--given: #4b5563;--note: #2563eb;--mistake: #fecaca;--button-bg: #f3f4f6;--button-fg: #111418;--button-active: #e5e7eb;--accent: #2563eb;--win: #16a34a}[data-theme=dark]{--bg: #111418;--fg: #f3f4f6;--muted: #9ca3af;--cell-bg: #1f2937;--cell-fg: #f3f4f6;--cell-border: #374151;--cage-border: #f3f4f6;--selected: #92400e;--highlight: #78350f;--given: #d1d5db;--note: #93c5fd;--mistake: #7f1d1d;--button-bg: #1f2937;--button-fg: #f3f4f6;--button-active: #374151;--accent: #60a5fa;--win: #4ade80}*{box-sizing:border-box;-webkit-tap-highlight-color:transparent}html,body,#root{margin:0;padding:0;height:100%}body{background:var(--bg);color:var(--fg);font-family:-apple-system,BlinkMacSystemFont,Segoe UI,Roboto,sans-serif;font-size:16px;overflow:hidden}#root{display:flex;flex-direction:column;min-height:100dvh;padding:env(safe-area-inset-top) env(safe-area-inset-right) env(safe-area-inset-bottom) env(safe-area-inset-left)}button{font:inherit;color:inherit;background:var(--button-bg);border:1px solid var(--cell-border);border-radius:8px;padding:.5rem .75rem;cursor:pointer;min-height:44px;min-width:44px;touch-action:manipulation}button:active{background:var(--button-active)}button[disabled]{opacity:.4;cursor:not-allowed}.app{display:flex;flex-direction:column;flex:1;width:100%;max-width:480px;margin:0 auto;padding:.5rem}.topbar{display:flex;align-items:center;justify-content:space-between;gap:.5rem;padding:.25rem .5rem .5rem}.topbar h1{margin:0;font-size:1.1rem}.topbar .right{display:flex;gap:.5rem}.menu{display:flex;flex-direction:column;gap:.75rem;padding:1rem}.menu h2{margin:.5rem 0 0;font-size:1rem;color:var(--muted)}.menu .row{display:flex;gap:.5rem;flex-wrap:wrap}.menu .row button{flex:1 1 calc(50% - .25rem)}.board-stack{position:relative}.board-wrap{display:flex;justify-content:center;padding:.5rem 0}.paused-overlay{position:absolute;top:0;right:0;bottom:0;left:0;background:var(--bg);-webkit-backdrop-filter:blur(8px);backdrop-filter:blur(8px);display:flex;align-items:center;justify-content:center;z-index:5}.paused-content{display:flex;flex-direction:column;align-items:center;gap:1rem}.paused-title{font-size:1.5rem;font-weight:700;color:var(--muted);letter-spacing:.05em;text-transform:uppercase}.paused-content button{font-size:1.1rem;padding:.75rem 2rem;background:var(--accent);color:#fff;border:none}.board{--cells: 4;--cell-size: min(calc((100vw - 1rem) / var(--cells)), calc(70vh / var(--cells)), 80px);display:grid;grid-template-columns:repeat(var(--cells),var(--cell-size));grid-template-rows:repeat(var(--cells),var(--cell-size));border:2px solid var(--cage-border);background:var(--cell-bg)}.cell{position:relative;width:var(--cell-size);height:var(--cell-size);background:var(--cell-bg);color:var(--cell-fg);border-right:1px solid var(--cell-border);border-bottom:1px solid var(--cell-border);display:flex;align-items:center;justify-content:center;font-size:calc(var(--cell-size) * .5);font-weight:600;-webkit-user-select:none;user-select:none;cursor:pointer;touch-action:manipulation}.cell.cage-right{border-right:2px solid var(--cage-border)}.cell.cage-bottom{border-bottom:2px solid var(--cage-border)}.cell.cage-left{border-left:2px solid var(--cage-border)}.cell.cage-top{border-top:2px solid var(--cage-border)}.cell.selected{background:var(--selected)}.cell.highlighted{background:var(--highlight)}.cell.mistake{background:var(--mistake)}.cell.given{color:var(--given);font-style:italic}.cage-label{position:absolute;top:1px;left:3px;font-size:calc(var(--cell-size) * .24);font-weight:700;color:var(--fg);letter-spacing:-.02em;pointer-events:none;z-index:1}.notes-grid{position:absolute;top:4px;right:4px;bottom:4px;left:4px;padding-top:calc(var(--cell-size) * .22);display:grid;grid-template-columns:repeat(3,1fr);grid-template-rows:repeat(3,1fr);gap:0;font-size:calc(var(--cell-size) * .16);font-weight:600;color:var(--note)}.notes-grid>span{display:flex;align-items:center;justify-content:center}.controls{display:flex;gap:.5rem;flex-wrap:wrap;justify-content:center;padding:.5rem}.keypad{display:grid;grid-template-columns:repeat(6,1fr);gap:.4rem;padding:.5rem}.keypad button{font-size:1.1rem;font-weight:600}.keypad button.active{background:var(--accent);color:#fff}.timer{font-variant-numeric:tabular-nums;font-weight:600}.modal-backdrop{position:fixed;top:0;right:0;bottom:0;left:0;background:#0000008c;display:flex;align-items:center;justify-content:center;z-index:10;padding:1rem}.modal{background:var(--bg);color:var(--fg);border-radius:16px;padding:1.5rem;max-width:360px;width:100%;box-shadow:0 10px 40px #0000004d;text-align:center}.modal h2{margin:0 0 .5rem;color:var(--win)}.modal .badges{display:flex;flex-wrap:wrap;gap:.4rem;justify-content:center;margin:.75rem 0}.modal .badge{background:var(--button-bg);border-radius:999px;padding:.25rem .6rem;font-size:.85rem}.modal .actions{display:flex;gap:.5rem;margin-top:1rem}.modal .actions button{flex:1}@keyframes win-flash-anim{0%{background:var(--cell-bg)}50%{background:var(--win)}to{background:var(--cell-bg)}}.win-flash .cell:not(.given){animation:win-flash-anim .6s ease-out}@media (prefers-reduced-motion: reduce){.win-flash .cell:not(.given){animation:none;background:var(--win);transition:background .4s ease}}.stats{padding:1rem;display:flex;flex-direction:column;gap:1rem}.stats-grid{display:grid;grid-template-columns:1fr 1fr;gap:.5rem}.stats-card{background:var(--button-bg);border-radius:12px;padding:.75rem}.stats-card .label{font-size:.8rem;color:var(--muted)}.stats-card .value{font-size:1.25rem;font-weight:700}.muted{color:var(--muted);font-size:.85rem}.wrong-banner{margin:.25rem .5rem;padding:.6rem .75rem;background:var(--mistake);color:var(--fg);border-radius:8px;font-weight:600;text-align:center;font-size:.95rem}.help-btn{font-weight:700;background:var(--accent);color:#fff;border-color:transparent;min-width:44px}.help-modal{text-align:left;max-width:420px}.help-title{margin:0 0 .5rem;color:var(--fg);font-size:1.25rem;text-align:center}.help-subtitle{margin:1rem 0 .5rem;font-size:.95rem;color:var(--muted);text-transform:uppercase;letter-spacing:.05em}.help-rules{margin:0;padding-left:1.1rem;font-size:.9rem;line-height:1.4}.help-rules li{margin-bottom:.35rem}.help-table{width:100%;border-collapse:collapse;font-size:.9rem}.help-table td{padding:.3rem .4rem;vertical-align:top}.help-table td:first-child{white-space:nowrap;width:1%}.help-table kbd{display:inline-block;background:var(--button-bg);border:1px solid var(--cell-border);border-radius:4px;padding:.1rem .4rem;font-family:ui-monospace,SFMono-Regular,Menlo,monospace;font-size:.8rem;font-weight:600}