*{margin:0;padding:0;box-sizing:border-box}:root{--cell-size: 55px;--cell-border: 1px;--subgrid-border: 3px;--grid-padding: 8px;--grid-outer-border: 3px;--gradient-start: #f6fff8;--gradient-end: #0b3954;--accent: #087e8b;--accent-dark: #0b3954;--accent-soft: rgba(8, 126, 139, .2);--accent-softer: rgba(8, 126, 139, .12);--accent-note: rgba(244, 159, 10, .2);--accent-note-text: #0b3954;--text-primary: #0b3954;--text-secondary: #087e8b;--text-muted: rgba(11, 57, 84, .7);--icon-muted: rgba(8, 126, 139, .7);--surface-primary: #f6fff8;--surface-elevated: rgba(246, 255, 248, .98);--surface-muted: #b8d5b8;--board-bg: #f6fff8;--board-border-color: #0b3954;--cell-border-color: #b8d5b8;--button-border-color: #b8d5b8;--border-color: var(--button-border-color);--toggle-bg: rgba(8, 126, 139, .12);--toggle-active-text: #0b3954;--shadow-soft: rgba(8, 126, 139, .18);--shadow-strong: rgba(11, 57, 84, .28);--overlay-backdrop: rgba(11, 57, 84, .7);--start-card-bg: rgba(246, 255, 248, .97);--text-on-accent: #f6fff8;--board-meta-color: rgba(11, 57, 84, .85);--board-meta-muted: rgba(244, 159, 10, .65);--accent-shadow-soft: rgba(8, 126, 139, .24);--accent-shadow-strong: rgba(11, 57, 84, .32);--error-color: #ef4444;--error-bg: #fee;--error-dark: #dc2626;--error-darker: #b91c1c;--error-gradient-start: #dc2626;--error-gradient-end: #991b1b;--success-gradient-start: #11998e;--success-gradient-end: #38ef7d;--success-highlight: #fbbf24;--success-highlight-soft: #fef3c7;--color-white: #ffffff;--color-light: #f8fafc;--min-touch-target: 48px;--mobile-spacing: 12px;--safe-area-top: env(safe-area-inset-top, 0px);--safe-area-bottom: env(safe-area-inset-bottom, 0px);--safe-area-left: env(safe-area-inset-left, 0px);--safe-area-right: env(safe-area-inset-right, 0px)}body{font-family:-apple-system,BlinkMacSystemFont,Segoe UI,Roboto,Oxygen,Ubuntu,Cantarell,Fira Sans,Droid Sans,Helvetica 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svg{width:20px;height:20px;position:relative;z-index:1;filter:drop-shadow(0 1px 2px rgba(0,0,0,.3))}.theme-icon-btn:hover{transform:scale(1.1);border-color:#fffc}.theme-icon-btn.active{border-color:#fff;box-shadow:0 0 0 3px #ffffff4d;transform:scale(1.05)}.start-screen-content{display:flex;flex-direction:column;align-items:center;gap:16px;width:100%;flex:1;overflow:auto}.start-screen-main{display:flex;gap:20px;width:100%;max-width:1000px;align-items:flex-start;justify-content:center}.start-screen-left{display:flex;flex-direction:column;gap:16px;align-items:center}.high-scores-card-compact{background:#fffffffa;border-radius:12px;padding:12px 16px;box-shadow:0 8px 20px #00000026;width:100%;max-width:200px}.high-scores-card-compact h3{font-size:.9rem;color:var(--text-primary);margin:0 0 8px;text-align:center}.high-scores-grid{display:grid;grid-template-columns:repeat(2,1fr);gap:6px}.high-score-compact{display:flex;flex-direction:column;align-items:center;gap:2px;padding:6px;background:var(--surface-muted);border-radius:8px;border:1px solid var(--button-border-color)}.high-score-label{font-size:.65rem;font-weight:600;color:var(--text-secondary);text-transform:uppercase;letter-spacing:.03em}.high-score-points{font-size:1.1rem;font-weight:700;color:var(--accent)}.start-card{background:var(--start-card-bg);border-radius:16px;padding:20px;box-shadow:0 12px 40px #0003;display:flex;flex-direction:column;gap:14px;width:min(100%,500px)}.start-description{font-size:.9rem;font-weight:500;color:var(--text-secondary);text-align:center}.sudoku-preview{width:100%;display:flex;justify-content:center;padding:0}.preview-grid{display:grid;grid-template-columns:repeat(3,1fr);gap:3px;width:90px;height:90px;background:var(--surface-muted);border-radius:10px;padding:6px;box-shadow:0 4px 12px #0000001f}.preview-cell{background:var(--surface-primary);border-radius:3px;display:flex;align-items:center;justify-content:center;font-size:.95rem;font-weight:700;color:var(--accent);transition:all .4s ease;animation:fadeInCell .5s ease}@keyframes fadeInCell{0%{opacity:0;transform:scale(.8)}to{opacity:1;transform:scale(1)}}.difficulty-buttons{display:flex;flex-direction:column;gap:8px}.difficulty-label{font-size:.85rem;font-weight:600;color:var(--text-secondary);text-align:center}.difficulty-grid{display:grid;grid-template-columns:repeat(2,1fr);gap:8px}.difficulty-btn{display:flex;flex-direction:column;align-items:center;gap:3px;padding:10px 8px;border:2px solid var(--button-border-color);background:var(--surface-primary);border-radius:10px;cursor:pointer;transition:all .3s ease;font-weight:600;color:var(--text-primary);outline:none;min-height:70px}.difficulty-btn:hover{border-color:var(--accent);background:var(--accent-soft);transform:translateY(-2px);box-shadow:0 6px 18px 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select:hover,.difficulty-dropdown:hover{border-color:var(--accent);box-shadow:0 4px 12px var(--accent-shadow-soft)}.difficulty-dropdown{background:#fffffff2}.new-game-btn{padding:12px 24px;font-size:1rem;border:none;background:linear-gradient(135deg,var(--accent) 0%,var(--accent-dark) 100%);color:var(--text-on-accent);border-radius:10px;cursor:pointer;font-weight:700;transition:all .3s ease;box-shadow:0 10px 30px #0003}.new-game-btn:hover{transform:translateY(-2px);box-shadow:0 16px 35px #00000040}.start-actions{display:flex;flex-direction:column;gap:10px;width:100%}.start-btn{width:100%}.secondary-btn{padding:12px 18px;font-size:.95rem;border:2px solid var(--border-color);background:var(--surface-primary);color:var(--text-primary);border-radius:10px;cursor:pointer;font-weight:600;transition:background .3s ease,border-color .3s ease,color .3s ease,box-shadow .3s ease;box-shadow:0 10px 22px var(--shadow-soft)}.secondary-btn:hover{background:var(--accent-soft);border-color:var(--accent);color:var(--accent-dark);box-shadow:0 14px 28px var(--accent-shadow-soft)}.secondary-btn:focus-visible{outline:3px solid var(--accent-soft);outline-offset:2px}.game-screen{display:flex;flex-direction:column;gap:20px;align-items:center;width:100%;--board-width: calc( 9 * var(--cell-size) + 2 * var(--grid-padding) + 2 * var(--grid-outer-border) )}@media (max-width: 768px){.game-screen{min-height:0;height:auto;max-height:100%}.game-container{flex:1;min-height:0;overflow:visible}}.game-header{display:grid;grid-template-columns:auto minmax(0,1fr) auto;align-items:center;gap:12px;width:100%;max-width:var(--board-width);margin:0 auto;padding-top:max(0px,var(--safe-area-top))}.game-title{text-align:center}.title-controls{display:inline-flex;align-items:center;gap:10px;justify-self:end}.icon-btn{display:inline-flex;align-items:center;justify-content:center;min-width:var(--min-touch-target);min-height:var(--min-touch-target);width:48px;height:48px;border-radius:12px;border:2px solid rgba(255,255,255,.45);background:#ffffff1f;color:#fff;cursor:pointer;transition:all .3s ease;position:relative;user-select:none;-webkit-user-select:none}.icon-btn:active{transform:scale(.95)}.icon-btn:after{content:"";position:absolute;top:-8px;right:-8px;bottom:-8px;left:-8px;pointer-events:none}.icon-btn svg{width:22px;height:22px;transition:transform .25s ease,opacity .25s ease}.pause-btn{justify-self:end;transition:all .3s ease}.pause-btn.active{background:var(--accent);border-color:var(--accent);color:var(--text-on-accent)}.pause-btn.active svg{transform:rotate(-90deg) scale(1.05);opacity:1}.pause-btn:not(.active) svg{transform:rotate(0) scale(1);opacity:.9}.pause-btn:not(.active){border-color:#ffffff40;background:#ffffff14}.theme-btn{transition:all .3s ease}.icon-btn:hover{background:#fff3;border-color:#fffc;transform:translateY(-1px)}.icon-btn:active{transform:translateY(0)}.icon-btn:focus-visible{outline:2px solid rgba(255,255,255,.9);outline-offset:3px}.menu-container{position:relative}.menu-btn.active{background:#ffffff40;border-color:#fffc}.menu-dropdown{position:absolute;top:calc(100% + 8px);right:0;background:var(--surface-elevated);border-radius:12px;box-shadow:0 8px 24px #0003;min-width:200px;overflow:hidden;z-index:1000;animation:menuSlideIn .2s ease-out}@keyframes menuSlideIn{0%{opacity:0;transform:translateY(-8px)}to{opacity:1;transform:translateY(0)}}.menu-item{display:flex;align-items:center;gap:12px;width:100%;padding:12px 16px;border:none;background:transparent;color:var(--text-primary);font-size:.9rem;font-weight:500;cursor:pointer;transition:background .2s ease;text-align:left}.menu-item:hover{background:var(--surface-muted)}.menu-item:active{background:var(--accent-soft)}.menu-item svg{color:var(--text-secondary)}.board-wrapper{display:flex;flex-direction:column;gap:6px;align-items:center;width:var(--board-width)}.board-meta{display:flex;justify-content:space-between;align-items:center;width:100%;padding:0 6px;font-size:.78rem;font-weight:600;letter-spacing:.08em;text-transform:uppercase;color:var(--board-meta-color)}.board-label{text-align:left}.board-timer{text-align:right;font-family:SFMono-Regular,Menlo,Roboto Mono,monospace;font-size:.84rem}.board-timer.paused{color:var(--board-meta-muted)}.completion-message{background:linear-gradient(135deg,var(--success-gradient-start) 0%,var(--success-gradient-end) 100%);color:var(--color-white);padding:15px 25px;border-radius:10px;text-align:center;margin-bottom:20px;font-size:1.1rem;font-weight:600;box-shadow:0 4px 15px #0003;animation:slideDown .5s ease-out}@keyframes slideDown{0%{opacity:0;transform:translateY(-20px)}to{opacity:1;transform:translateY(0)}}.game-container{display:flex;flex-direction:column;gap:20px;align-items:center}.game-container.paused{pointer-events:none;filter:blur(2px);opacity:.6}.sudoku-grid{background:var(--board-bg);padding:var(--grid-padding);border-radius:12px;box-shadow:0 10px 40px var(--shadow-strong);display:inline-block;border:var(--grid-outer-border) solid var(--board-border-color);width:var(--board-width)}.sudoku-row{display:flex}.sudoku-cell{width:var(--cell-size);height:var(--cell-size);border:var(--cell-border) solid var(--cell-border-color);display:flex;justify-content:center;align-items:center;cursor:pointer;transition:all .15s ease;background:var(--surface-primary);position:relative;user-select:none;-webkit-user-select:none;-webkit-touch-callout:none;touch-action:manipulation}.sudoku-cell:active{transform:scale(.97);transition:transform .05s ease}.sudoku-cell:hover{background:var(--cell-hover-bg)}.sudoku-cell.selected{background:var(--accent);color:#fff;box-shadow:inset 0 0 0 2px var(--accent-dark);z-index:10}.sudoku-cell.highlighted{background:var(--accent-soft)}.sudoku-cell.initial{background:var(--cell-initial-bg)}.sudoku-cell.initial .cell-number{font-weight:700;color:var(--text-primary);font-size:1.8rem}.sudoku-cell .cell-number{font-size:1.6rem;font-weight:600;color:var(--accent)}.sudoku-cell.selected .cell-number{color:#fff}.sudoku-cell.selected .cell-notes span{color:var(--accent-softer)}.sudoku-cell.selected .cell-notes span.active{color:var(--color-light)}.sudoku-cell.same-number{background:var(--accent-softer)}.sudoku-cell.diagonal{background-color:var(--accent-softer)}.sudoku-cell.hyper-region{background-color:var(--accent-note)}.sudoku-cell.same-number.selected{background:var(--accent)}.sudoku-cell.same-number .cell-notes span.active{color:var(--accent);font-weight:700}.cell-notes span.highlighted-note{color:var(--color-light)!important;background-color:var(--accent);border-radius:2px;font-weight:700}.sudoku-cell.invalid-placement{background-color:color-mix(in srgb,var(--error-color) 10%,transparent)}.sudoku-cell.invalid-placement.highlighted{background-color:color-mix(in srgb,var(--error-color) 15%,transparent)}.sudoku-cell.conflict{background:var(--error-bg)!important}.sudoku-cell.conflict .cell-number{color:var(--error-color)!important;font-weight:700}.sudoku-cell.border-right{border-right:var(--subgrid-border) solid var(--board-border-color)}.sudoku-cell.border-bottom{border-bottom:var(--subgrid-border) solid var(--board-border-color)}.cell-notes{display:grid;grid-template-columns:repeat(3,1fr);grid-template-rows:repeat(3,1fr);width:100%;height:100%;padding:0;gap:0;place-items:center}.cell-notes span{display:flex;justify-content:center;align-items:center;width:100%;height:100%;font-size:.7rem;color:var(--icon-muted);font-weight:500}.cell-notes span.active{color:var(--accent);font-weight:600}.controls-panel{display:flex;flex-direction:column;gap:15px;align-items:center;width:100%;max-width:var(--board-width)}.toolbar{display:flex;gap:10px;background:var(--surface-primary);padding:15px;border-radius:12px;box-shadow:0 4px 20px var(--shadow-soft);width:100%;max-width:var(--board-width);justify-content:space-between}.tool-btn{flex:1;display:flex;flex-direction:column;align-items:center;gap:5px;padding:12px 8px;border:2px solid var(--button-border-color);background:var(--surface-primary);border-radius:10px;cursor:pointer;transition:all .2s ease;font-weight:600;font-size:.85rem;color:var(--text-secondary);position:relative}.tool-btn svg{width:24px;height:24px;color:var(--icon-muted)}.tool-btn:hover:not(:disabled){background:var(--surface-muted);border-color:var(--accent);transform:translateY(-2px);box-shadow:0 4px 12px var(--accent-shadow-soft)}.tool-btn:hover:not(:disabled) svg{color:var(--accent)}.tool-btn:active:not(:disabled){transform:translateY(0)}.tool-btn:disabled{opacity:.4;cursor:not-allowed}.tool-btn span{font-size:.75rem}.notes-btn{position:relative}.notes-btn.active{background:var(--accent);color:#fff;border-color:var(--accent)}.notes-btn.active svg{color:#fff}.toggle-switch{position:absolute;top:8px;right:8px;background:var(--toggle-bg);border-radius:10px;padding:2px 6px;font-size:.6rem;font-weight:700}.notes-btn.active .toggle-switch{background:#fff;color:var(--accent)}.toggle-slider{color:var(--icon-muted)}.toggle-slider.on{color:var(--toggle-active-text)}.number-pad{display:grid;grid-template-columns:repeat(9,1fr);gap:8px;background:var(--surface-primary);padding:15px;border-radius:12px;box-shadow:0 4px 20px var(--shadow-soft);width:100%;max-width:var(--board-width)}.number-button{aspect-ratio:1;border:2px solid var(--button-border-color);background:var(--surface-primary);border-radius:10px;cursor:pointer;transition:all .2s ease;display:flex;flex-direction:column;justify-content:center;align-items:center;gap:4px;min-width:0;min-height:0;user-select:none;-webkit-user-select:none;touch-action:manipulation;position:relative}.number-button:before{content:"";position:absolute;top:-4px;right:-4px;bottom:-4px;left:-4px;pointer-events:none}.number-button:hover:not(:disabled){background:var(--accent);border-color:var(--accent);transform:scale(1.1);box-shadow:0 4px 12px var(--accent-shadow-strong);z-index:10}.number-button:active:not(:disabled){transform:scale(1.05)}.number-button:disabled{opacity:.3;cursor:not-allowed}.number-button.notes-mode{background:var(--accent-note);border-color:var(--accent)}.number-label{font-size:1.5rem;font-weight:700;color:var(--text-primary);line-height:1}.number-availability{font-size:.7rem;font-weight:600;color:var(--text-muted);line-height:1}.number-button.notes-mode .number-label{color:var(--accent-note-text)}.number-button.notes-mode .number-availability{color:var(--accent)}.number-button:hover:not(:disabled) .number-label,.number-button:hover:not(:disabled) .number-availability{color:var(--text-on-accent)}.number-availability.depleted{color:var(--error-color)}.pause-overlay,.theme-overlay{position:fixed;top:0;right:0;bottom:0;left:0;background:var(--overlay-backdrop);display:flex;align-items:center;justify-content:center;padding:20px;z-index:20}.pause-card,.theme-card{background:var(--surface-elevated);border-radius:18px;padding:32px;max-width:680px;width:min(100%,680px);box-shadow:0 25px 60px #0f172a59;display:flex;flex-direction:column;gap:18px}.pause-card h2,.theme-card h2{font-size:1.4rem;color:var(--text-primary)}.pause-card p,.theme-card p{font-size:.95rem;color:var(--text-secondary)}.pause-card{text-align:center;max-width:480px;width:min(100%,480px)}.theme-card{text-align:left}.theme-card .secondary-btn{align-self:flex-end;background:var(--accent-soft);color:var(--text-primary);border-color:var(--button-border-color)}.theme-card .secondary-btn:hover{background:var(--accent-softer);border-color:var(--accent);color:var(--text-primary)}.import-export-modal{position:fixed;top:0;right:0;bottom:0;left:0;background:var(--overlay-backdrop);display:flex;align-items:center;justify-content:center;padding:24px;z-index:12000}.import-export-card{background:var(--surface-elevated);border-radius:18px;padding:28px;width:min(100%,720px);box-shadow:0 25px 60px #0f172a52;display:flex;flex-direction:column;gap:20px}.import-export-card .modal-header{display:flex;align-items:center;justify-content:space-between;gap:12px}.import-export-card .modal-header h2{font-size:1.35rem;color:var(--text-primary);margin:0}.import-export-tabs{display:flex;background:var(--surface-muted);padding:4px;border-radius:12px;gap:8px}.tab-btn{flex:1;display:flex;align-items:center;justify-content:center;gap:8px;padding:10px 12px;border-radius:10px;border:none;background:transparent;color:var(--text-secondary);font-weight:600;cursor:pointer;transition:background .2s ease,color .2s ease}.tab-btn.active{background:var(--accent-soft);color:var(--accent-dark)}.import-section,.export-section{display:flex;flex-direction:column;gap:16px}.form-label{font-size:.9rem;font-weight:600;color:var(--text-secondary)}.form-select,.form-textarea{width:100%;border-radius:10px;border:1px solid var(--button-border-color);background:var(--surface-muted);color:var(--text-primary);padding:10px 12px;font-size:.95rem;transition:border-color .2s ease,box-shadow .2s ease}.form-select:focus-visible,.form-textarea:focus-visible{outline:none;border-color:var(--accent);box-shadow:0 0 0 3px 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.cell-number{font-size:1.45rem}.cell-notes span{font-size:.54rem}.toolbar{padding:5px;gap:4px;display:grid;grid-template-columns:repeat(2,1fr)}.tool-btn{padding:8px 4px;gap:2px;min-height:50px}.tool-btn svg{width:18px;height:18px}.tool-btn span{font-size:.62rem}.toggle-switch{display:none}.number-pad{grid-template-columns:repeat(9,1fr);gap:3px;padding:6px 4px}.number-label{font-size:1.25rem}.number-button{border-radius:7px;min-height:44px;padding:2px;aspect-ratio:1}.number-availability{font-size:.58rem}.game-header{gap:3px;padding:max(3px,var(--safe-area-top)) 2px 3px 2px;min-height:auto}.game-title{font-size:.95rem;line-height:1.1}.game-info{gap:2px}.game-stats{gap:3px;flex-wrap:wrap}.stat-item{padding:2px 5px;font-size:.65rem}.lives-container{padding:2px 5px;gap:2px}.life-icon{width:14px;height:14px}.title-controls{gap:2px}.icon-btn{width:36px;height:36px;min-width:36px;min-height:36px}.icon-btn 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svg{width:16px;height:16px}.game-container{gap:6px;flex:1;display:flex;flex-direction:column;justify-content:center}.controls-panel{gap:5px}.board-wrapper{flex-shrink:0}.number-availability{font-size:.5rem}}@media (min-width: 768px){.controls-panel{align-items:stretch;width:100%;max-width:var(--board-width);margin:0 auto}.toolbar{display:grid;grid-template-columns:repeat(2,1fr);gap:12px;width:100%;max-width:100%}.number-pad{grid-template-columns:repeat(3,1fr);gap:12px;padding:18px;width:100%;max-width:var(--board-width);border:var(--grid-outer-border) solid var(--board-border-color);border-radius:12px;justify-items:center}.number-button{width:var(--cell-size);height:var(--cell-size);border-radius:10px;font-size:1.4rem}}@media (min-width: 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-1;grid-row:2;flex-direction:column;align-items:center;justify-content:center;gap:2px;width:100%;padding-top:0;margin-top:2px}.game-title{margin:0;font-size:1.05rem;line-height:1.1}.game-stats{gap:3px;flex-wrap:nowrap;justify-content:center}.stat-item{padding:1px 5px;gap:2px;border-radius:4px;font-size:.7rem;background:#ffffff1a;white-space:nowrap}.stat-label{display:none}.lives-container{padding:1px 5px;gap:2px}.life-icon{width:16px;height:16px}}.stat-item.stat-animate{animation:statPulse .5s ease-out}@keyframes statPulse{0%{transform:scale(1)}50%{transform:scale(1.1);background:#ffffff4d}to{transform:scale(1)}}.stat-label{color:#fffc;font-size:.85rem}.stat-value{color:#fff;font-size:1rem}.lives-container{gap:4px;padding:6px 8px}.life-icon{transition:all .3s ease}.life-icon.active{color:var(--error-color)}.life-icon.inactive{color:#ffffff4d}.high-scores-card{background:#fffffffa;border-radius:18px;padding:24px 32px;box-shadow:0 18px 50px #00000040;width:min(100%,420px)}.high-scores-card h2{font-size:1.4rem;color:var(--text-primary);margin-bottom:16px;text-align:center}.high-scores-list{display:flex;flex-direction:column;gap:12px}.high-score-item{display:flex;justify-content:space-between;align-items:center;padding:12px 16px;background:var(--surface-muted);border-radius:10px;border:2px solid var(--button-border-color)}.high-score-difficulty{font-weight:600;color:var(--text-primary);font-size:.95rem}.high-score-value{font-weight:700;color:var(--accent);font-size:1.1rem}@media (min-width: 640px){.high-scores-grid{grid-template-columns:repeat(4,1fr)}.high-scores-card-compact{max-width:600px}}@media (min-width: 768px){.start-screen-header{flex-direction:row;justify-content:space-between;align-items:center;width:100%}.start-screen-actions{gap:20px}.difficulty-grid{grid-template-columns:repeat(2,1fr)}.sudoku-preview{padding:12px 0}.preview-grid{width:110px;height:110px}.preview-cell{font-size:1.2rem}}@media (min-width: 1024px){.difficulty-grid{grid-template-columns:repeat(3,1fr);gap:10px}.difficulty-btn{padding:12px 8px;min-height:80px}.difficulty-icon{font-size:1.6rem}.difficulty-name{font-size:.85rem}.difficulty-desc{font-size:.65rem}.preview-grid{width:100px;height:100px}.preview-cell{font-size:1rem}.start-card{max-width:550px}.start-screen-main{gap:24px}}.game-over-overlay{position:fixed;top:0;left:0;width:100%;height:100%;background:var(--overlay-backdrop);display:flex;align-items:center;justify-content:center;z-index:9999;animation:fadeIn .3s ease-out}.game-over-card{background:linear-gradient(135deg,var(--error-gradient-start) 0%,var(--error-gradient-end) 100%);border-radius:20px;padding:40px;box-shadow:0 20px 60px #0006;max-width:400px;width:90%;text-align:center;animation:slideUp .4s ease-out}.game-over-title{font-size:2.5rem;font-weight:800;color:var(--color-white);margin-bottom:12px;text-shadow:2px 2px 4px rgba(0,0,0,.3)}.game-over-message{font-size:1.1rem;color:#ffffffe6;margin-bottom:24px;font-weight:500}.game-over-score{background:#ffffff26;padding:20px;border-radius:12px;margin-bottom:28px;display:flex;flex-direction:column;gap:8px}.game-over-score>span:first-child{color:#fffc;font-size:.9rem;font-weight:600}.game-over-score-value{font-size:2.5rem;font-weight:800;color:var(--color-white);text-shadow:2px 2px 4px rgba(0,0,0,.2)}.game-over-actions{display:flex;flex-direction:column;gap:12px}.game-over-actions .secondary-btn{width:100%}.game-over-card .secondary-btn{background:#ffffff1f;border-color:#ffffffa6;color:var(--color-white);box-shadow:none}.game-over-card .secondary-btn:hover{background:#fff3;border-color:#ffffffd9;color:var(--color-white);box-shadow:none}.game-over-card .secondary-btn:focus-visible{outline:3px solid rgba(255,255,255,.7)}.completion-message{background:linear-gradient(135deg,var(--success-gradient-start) 0%,var(--success-gradient-end) 100%);color:var(--color-white);padding:20px 25px;border-radius:10px;text-align:center;margin-bottom:20px;font-size:1.1rem;font-weight:600;box-shadow:0 4px 15px #0003;animation:slideDown .5s ease-out;display:flex;flex-direction:column;gap:12px}.completion-score{display:flex;flex-direction:column;gap:8px;font-size:1rem}.completion-score strong{font-size:1.4rem;font-weight:800}.new-high-score{color:var(--success-highlight);font-weight:700;font-size:.95rem;animation:pulse 1s ease-in-out infinite}.perfect-game{color:var(--success-highlight-soft);font-weight:600;font-size:.9rem}@keyframes fadeIn{0%{opacity:0}to{opacity:1}}@keyframes slideUp{0%{opacity:0;transform:translateY(30px)}to{opacity:1;transform:translateY(0)}}@keyframes pulse{0%,to{opacity:1;transform:scale(1)}50%{opacity:.8;transform:scale(1.05)}}@keyframes slideIn{0%{opacity:0;transform:scale(.95)}to{opacity:1;transform:scale(1)}}.sudoku-cell.hint-highlight-candidate{background:#087e8b80!important;box-shadow:inset 0 0 0 3px 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hintPulse{0%,to{opacity:1;transform:scale(1)}50%{opacity:.9;transform:scale(1.02)}}.error-boundary-overlay{position:fixed;top:0;left:0;width:100%;height:100%;background:var(--overlay-backdrop);display:flex;align-items:center;justify-content:center;z-index:9999;animation:fadeIn .3s ease-out}.error-boundary-card{background:linear-gradient(135deg,#dc2626,#991b1b);border-radius:20px;padding:40px;box-shadow:0 20px 60px #0006;max-width:500px;width:90%;text-align:center;animation:slideUp .4s ease-out}.error-boundary-title{font-size:2.2rem;font-weight:800;color:var(--color-white);margin-bottom:16px;text-shadow:2px 2px 4px rgba(0,0,0,.3)}.error-boundary-message{font-size:1.1rem;color:#fffffff2;margin-bottom:12px;font-weight:600}.error-boundary-details{font-size:.95rem;color:#ffffffd9;margin-bottom:28px;line-height:1.5}.error-boundary-actions{display:flex;flex-direction:column;gap:12px;margin-bottom:20px}.error-boundary-actions 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var(--accent-soft);outline-offset:2px}kbd{display:inline-flex;align-items:center;justify-content:center;min-width:28px;padding:4px 8px;border-radius:6px;border:1px solid var(--button-border-color);background:var(--surface-muted);color:var(--text-primary);font-size:.8rem;font-weight:600;box-shadow:inset 0 -2px #0f172a14}.keyboard-shortcut-tooltip{position:fixed;right:24px;bottom:24px;display:flex;align-items:center;gap:12px;padding:14px 18px;border-radius:14px;background:var(--surface-elevated);color:var(--text-primary);box-shadow:0 18px 45px #0f172a40;border-left:4px solid var(--accent);z-index:40}.keyboard-shortcut-tooltip p{margin:0;font-weight:600;font-size:.95rem;display:flex;align-items:center;gap:8px}.keyboard-shortcut-tooltip kbd{background:var(--accent-soft);border-color:transparent;color:var(--accent-dark)}.tooltip-dismiss{-webkit-appearance:none;-moz-appearance:none;appearance:none;border:none;background:transparent;color:var(--text-muted);font-size:1.25rem;line-height:1;cursor:pointer;padding:4px;border-radius:50%;transition:color .2s ease,background .2s ease}.tooltip-dismiss:hover,.tooltip-dismiss:focus-visible{color:var(--accent-dark);background:#087e8b1f;outline:none}.shortcuts-overlay{position:fixed;top:0;right:0;bottom:0;left:0;background:var(--overlay-backdrop);display:flex;align-items:center;justify-content:center;padding:24px;z-index:30}.shortcuts-card{background:var(--surface-elevated);border-radius:20px;padding:32px;width:min(100%,620px);box-shadow:0 25px 60px #0f172a59;display:flex;flex-direction:column;gap:24px}.shortcuts-header h2{font-size:1.5rem;color:var(--text-primary);margin-bottom:6px}.shortcuts-header p{font-size:.95rem;color:var(--text-secondary)}.shortcuts-grid{display:grid;gap:20px;grid-template-columns:repeat(auto-fit,minmax(220px,1fr))}.shortcuts-section h3{font-size:1.05rem;color:var(--text-primary);margin-bottom:12px}.shortcuts-section ul{list-style:none;display:flex;flex-direction:column;gap:12px;padding:0;margin:0}.shortcuts-section li{display:flex;align-items:center;gap:12px;font-size:.95rem;color:var(--text-secondary)}.shortcut-keys{display:inline-flex;align-items:center;gap:6px;flex-wrap:wrap}.shortcut-key-group{display:inline-flex;align-items:center;gap:6px}.shortcut-separator{font-weight:600;color:var(--text-muted);margin:0 2px}.shortcut-description{flex:1}.shortcuts-actions{display:flex;justify-content:flex-end}@media (max-width: 640px){.keyboard-shortcut-tooltip{right:16px;left:16px;bottom:16px;justify-content:space-between}.shortcuts-card{padding:24px}.shortcuts-section li{align-items:flex-start;flex-direction:column;gap:6px}.shortcut-description{width:100%}}.settings-overlay{position:fixed;top:0;right:0;bottom:0;left:0;background:var(--overlay-backdrop);display:flex;align-items:center;justify-content:center;padding:20px;z-index:20}.settings-card{background:var(--surface-elevated);border-radius:18px;padding:32px;max-width:600px;width:min(100%,600px);max-height:85vh;box-shadow:0 25px 60px #0f172a59;display:flex;flex-direction:column;gap:24px;overflow:hidden}.settings-card h2{font-size:1.8rem;color:var(--text-primary);margin:0}.settings-subtitle{font-size:.95rem;color:var(--text-secondary);margin:-8px 0 0}.settings-tabs{display:flex;gap:4px;border-bottom:2px solid var(--button-border-color);padding-bottom:0;flex-shrink:0}.settings-tab{background:transparent;border:none;padding:12px 16px;font-size:.9rem;font-weight:600;color:var(--text-secondary);cursor:pointer;border-bottom:3px solid transparent;margin-bottom:-2px;transition:all .2s 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ease}.settings-item:hover{background:var(--accent-soft)}.settings-item-info{flex:1;display:flex;flex-direction:column;gap:4px}.settings-item-label{font-size:.95rem;font-weight:600;color:var(--text-primary)}.settings-item-description{font-size:.85rem;color:var(--text-secondary);line-height:1.4}.settings-checkbox{width:22px;height:22px;cursor:pointer;accent-color:var(--accent)}.settings-checkbox:disabled{opacity:.5;cursor:not-allowed}.settings-number-input{width:80px;padding:8px 12px;border:2px solid var(--button-border-color);border-radius:8px;font-size:.95rem;font-weight:600;color:var(--text-primary);background:var(--surface-primary);text-align:center}.settings-number-input:focus{outline:none;border-color:var(--accent)}.settings-actions{display:flex;justify-content:space-between;gap:12px;padding-top:16px;border-top:2px solid var(--button-border-color);flex-shrink:0;margin-top:auto}.settings-actions .secondary-btn{background:var(--accent-soft);color:var(--text-primary);border-color:var(--button-border-color)}.settings-actions .secondary-btn:hover{background:var(--accent-softer);border-color:var(--accent)}.settings-actions .primary-btn{background:var(--accent);color:#fff;border:2px solid var(--accent);padding:12px 24px;border-radius:10px;font-weight:600;font-size:.95rem;cursor:pointer;transition:all .2s ease}.settings-actions .primary-btn:hover{background:var(--accent-dark);border-color:var(--accent-dark);transform:translateY(-1px);box-shadow:0 4px 12px var(--accent-shadow-soft)}.settings-language-description{font-size:.95rem;color:var(--text-secondary);margin:-8px 0 16px;line-height:1.5}.settings-language-note{font-size:.85rem;color:var(--text-muted);margin:16px 0 0;padding:12px;background:var(--surface-muted);border-radius:8px;border-left:3px solid var(--accent)}.language-options{gap:12px}.language-item{position:relative}.language-item input[type=radio]{width:20px;height:20px;cursor:pointer;accent-color:var(--accent);flex-shrink:0}.language-item input[type=radio]:checked+.settings-item-info:before{content:"";position:absolute;top:0;left:0;right:0;bottom:0;border-radius:12px;pointer-events:none}.language-item:has(input[type=radio]:checked){background:var(--accent-soft);border:2px solid var(--accent)}@media (max-width: 640px){.settings-card{padding:24px;max-height:90vh}.settings-tabs{overflow-x:auto;scrollbar-width:none;-webkit-overflow-scrolling:touch}.settings-tabs::-webkit-scrollbar{display:none}.settings-tab{padding:10px 12px;font-size:.85rem;white-space:nowrap}.settings-item{padding:12px}.settings-item-label{font-size:.9rem}.settings-item-description{font-size:.8rem}.settings-actions{flex-direction:column-reverse}.settings-actions .primary-btn,.settings-actions .secondary-btn{width:100%}}.achievement-toast-container{position:fixed;top:24px;right:24px;display:flex;flex-direction:column;gap:12px;z-index:1300}.achievement-toast{width:320px;display:flex;align-items:flex-start;gap:12px;padding:16px 18px;border-radius:16px;border:1px solid var(--border-color);border-left:4px solid var(--accent);background:var(--surface-elevated);box-shadow:0 22px 44px var(--shadow-strong);color:var(--text-primary);cursor:pointer;text-align:left;transition:transform .2s ease,box-shadow .2s ease}.achievement-toast:hover{transform:translateY(-2px);box-shadow:0 26px 52px var(--shadow-strong)}.achievement-toast:focus-visible{outline:3px solid var(--accent-soft);outline-offset:2px}.achievement-toast-icon{font-size:2rem;line-height:1}.achievement-toast-content{flex:1}.achievement-toast-title{margin:0;font-size:.8rem;text-transform:uppercase;letter-spacing:.05em;color:var(--accent-dark);font-weight:700}.achievement-toast-name{margin:4px 0;font-size:1.05rem;font-weight:700}.achievement-toast-description{margin:0;color:var(--text-secondary);font-size:.85rem}.achievement-toast-reward{display:inline-block;margin-top:6px;font-weight:600;color:var(--accent);font-size:.85rem}.achievement-toast-dismiss{margin-left:8px;color:var(--text-secondary);font-size:1.25rem;line-height:1;cursor:pointer}.achievement-toast-dismiss:hover{color:var(--accent)}.achievements-modal{position:fixed;top:0;right:0;bottom:0;left:0;background:var(--overlay-backdrop);display:flex;align-items:center;justify-content:center;padding:32px 20px;z-index:1250}.achievements-card{width:min(960px,100%);max-height:90vh;display:flex;flex-direction:column;background:var(--surface-elevated);border-radius:24px;border:1px solid var(--border-color);box-shadow:0 32px 64px var(--shadow-strong);color:var(--text-primary)}.achievements-card .modal-header{display:flex;align-items:center;justify-content:space-between;padding:28px 32px 18px;border-bottom:1px solid var(--border-color)}.achievements-card .modal-header h2{margin:0;font-size:1.6rem}.achievements-card .modal-header .icon-btn{font-size:1.4rem;color:var(--text-secondary)}.achievements-card .modal-header .icon-btn:hover{color:var(--accent)}.share-message{margin:12px 32px 0;padding:12px 16px;border-radius:12px;background:var(--accent-soft);color:var(--accent-dark);font-weight:600}.achievements-scroll{padding:24px 32px 32px;overflow-y:auto;display:flex;flex-direction:column;gap:28px}.achievement-section{display:flex;flex-direction:column;gap:18px}.achievement-section-header{display:flex;align-items:baseline;justify-content:space-between;font-weight:600;color:var(--text-secondary)}.achievements-grid{display:grid;gap:18px;grid-template-columns:repeat(auto-fit,minmax(240px,1fr))}.achievement-card{padding:18px;border-radius:18px;border:1px solid var(--border-color);background:var(--surface-primary);display:flex;flex-direction:column;gap:10px;color:var(--text-primary);box-shadow:0 16px 30px var(--shadow-soft);transition:transform .2s ease,box-shadow .2s ease,border-color .2s ease;position:relative}.achievement-card.unlocked{border-color:var(--accent);box-shadow:0 18px 36px var(--accent-shadow-soft)}.achievement-card.locked{opacity:.75}.achievement-card:hover{transform:translateY(-2px);box-shadow:0 22px 44px var(--shadow-soft)}.achievement-card.unlocked:hover{box-shadow:0 24px 48px var(--accent-shadow-strong)}.achievement-card-header{display:flex;align-items:center;gap:12px}.achievement-card-icon{font-size:2rem}.achievement-rarity{margin:0;font-size:.8rem;text-transform:uppercase;letter-spacing:.05em;color:var(--text-secondary)}.achievement-description{margin:0;color:var(--text-secondary);font-size:.9rem}.achievement-reward{margin:0;font-weight:600;color:var(--accent);font-size:.85rem}.achievement-progress{width:100%;height:8px;border-radius:999px;background:#94a3b840;overflow:hidden}.achievement-progress-bar{height:100%;background:var(--accent);transition:width .3s ease}.achievement-progress-text,.achievement-unlocked-date{margin:0;font-size:.8rem;color:var(--text-secondary)}.share-btn{align-self:flex-start;margin-top:auto;padding:6px 14px;border-radius:999px;border:1px solid var(--accent);background:var(--accent-soft);color:var(--accent-dark);font-weight:600;transition:background .2s ease,transform .2s ease}.share-btn:hover{background:var(--accent);color:var(--text-on-accent);transform:translateY(-1px)}.achievements-btn{position:relative}.achievement-count{position:absolute;top:-6px;right:-6px;background:var(--accent);color:var(--text-on-accent);border-radius:999px;padding:2px 6px;font-size:.7rem;font-weight:700;box-shadow:0 8px 16px var(--accent-shadow-soft)}.sr-only{position:absolute;width:1px;height:1px;padding:0;margin:-1px;overflow:hidden;clip:rect(0,0,0,0);white-space:nowrap;border:0}@media (max-width: 768px){.achievement-toast{width:min(90vw,320px)}.achievements-card{border-radius:18px}.achievements-card .modal-header,.achievements-scroll{padding-left:20px;padding-right:20px}.achievements-grid{grid-template-columns:1fr}}@media (hover: none) and (pointer: coarse){.sudoku-cell,.number-button,.tool-btn,.icon-btn,.difficulty-btn{transition:transform .1s ease,background-color .15s ease}.sudoku-cell:active{transform:scale(.95);background:var(--accent-soft)!important}.number-button:active:not(:disabled){transform:scale(.92)}.tool-btn:active:not(:disabled){transform:scale(.94);background:var(--accent-soft)}.icon-btn:active{transform:scale(.92)}.difficulty-btn:active{transform:scale(.96)}.sudoku-cell:hover{background:var(--surface-primary)}.sudoku-cell.selected:hover{background:var(--accent)}.number-button{box-shadow:0 2px 8px #0000001a}.number-button:active:not(:disabled){box-shadow:0 1px 4px #00000026}}@media (max-width: 768px) and (orientation: landscape){.app{padding:8px}.game-header{padding:4px 0}.game-title{font-size:1.2rem}.stat-item{font-size:.7rem;padding:3px 6px}.game-container{gap:10px;flex-direction:row;justify-content:center;align-items:flex-start}.board-wrapper{flex-shrink:0}.controls-panel{max-width:300px}.toolbar{display:flex;flex-direction:column}.number-pad{grid-template-columns:repeat(3,1fr)}}@media (prefers-reduced-motion: reduce){*,*:before,*:after{animation-duration:.01ms!important;animation-iteration-count:1!important;transition-duration:.01ms!important}}@media (prefers-contrast: high){.sudoku-cell{border-width:2px}.sudoku-cell.border-right{border-right-width:4px}.sudoku-cell.border-bottom{border-bottom-width:4px}.icon-btn,.tool-btn,.number-button{border-width:3px}}@keyframes spin{0%{transform:rotate(0)}to{transform:rotate(360deg)}}