:root{--font-main: "Outfit", "Poppins", -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, sans-serif;--trans-fast: .15s cubic-bezier(.4, 0, .2, 1);--trans-normal: .25s cubic-bezier(.4, 0, .2, 1);--trans-spring: .4s cubic-bezier(.175, .885, .32, 1.275);--accent-primary: #6366f1;--accent-primary-hover: #4f46e5;--accent-secondary: #06b6d4;--accent-error: #ef4444;--accent-error-glow: rgba(239, 68, 68, .4);--accent-success: #10b981;--accent-warning: #f59e0b}body[data-theme=dark]{--bg-gradient-start: #0f172a;--bg-gradient-mid: #1e1b4b;--bg-gradient-end: #0f2c42;--card-bg: rgba(30, 41, 59, .72);--card-border: rgba(255, 255, 255, .12);--card-shadow: 0 16px 36px -8px rgba(0, 0, 0, .5), 0 0 0 1px rgba(255, 255, 255, .08);--text-main: #f8fafc;--text-muted: #94a3b8;--text-dim: #64748b;--grid-border: rgba(148, 163, 184, .25);--grid-thick-border: #818cf8;--cell-bg: rgba(15, 23, 42, .6);--cell-hover: rgba(99, 102, 241, .16);--cell-highlight: rgba(99, 102, 241, .15);--cell-same-num: rgba(99, 102, 241, .28);--cell-selected: #4f46e5;--cell-selected-text: #ffffff;--cell-selected-glow: 0 0 18px rgba(99, 102, 241, .65);--cell-given-color: #f1f5f9;--cell-user-color: #38bdf8;--cell-conflict-bg: rgba(239, 68, 68, .32);--cell-conflict-text: #fca5a5;--note-color: #94a3b8;--btn-bg: rgba(51, 65, 85, .7);--btn-hover: rgba(71, 85, 105, .9);--btn-active: rgba(99, 102, 241, .85);--modal-backdrop: rgba(15, 23, 42, .85)}body[data-theme=light]{--bg-gradient-start: #e0e7ff;--bg-gradient-mid: #ede9fe;--bg-gradient-end: #ccfbf1;--card-bg: rgba(255, 255, 255, .82);--card-border: rgba(255, 255, 255, .8);--card-shadow: 0 14px 34px -6px rgba(99, 102, 241, .15), 0 0 0 1px rgba(99, 102, 241, .08);--text-main: #0f172a;--text-muted: #475569;--text-dim: #94a3b8;--grid-border: rgba(100, 116, 139, .22);--grid-thick-border: #4f46e5;--cell-bg: rgba(255, 255, 255, .9);--cell-hover: rgba(99, 102, 241, .12);--cell-highlight: rgba(99, 102, 241, .1);--cell-same-num: rgba(99, 102, 241, .22);--cell-selected: #4f46e5;--cell-selected-text: #ffffff;--cell-selected-glow: 0 0 14px rgba(99, 102, 241, .4);--cell-given-color: #0f172a;--cell-user-color: #0284c7;--cell-conflict-bg: rgba(254, 202, 202, .8);--cell-conflict-text: #b91c1c;--note-color: #64748b;--btn-bg: rgba(241, 245, 249, .85);--btn-hover: rgba(226, 232, 240, .95);--btn-active: #4f46e5;--modal-backdrop: rgba(15, 23, 42, .45)}*,*:before,*:after{box-sizing:border-box;margin:0;padding:0;-webkit-tap-highlight-color:transparent}body{font-family:var(--font-main);background:linear-gradient(135deg,var(--bg-gradient-start),var(--bg-gradient-mid),var(--bg-gradient-end));background-size:300% 300%;animation:gradientFlow 16s ease infinite;color:var(--text-main);min-height:100vh;display:flex;justify-content:center;align-items:center;padding:16px;overflow-x:hidden;transition:background .4s ease,color .3s ease}@keyframes gradientFlow{0%{background-position:0% 50%}50%{background-position:100% 50%}to{background-position:0% 50%}}.glass-card{background:var(--card-bg);backdrop-filter:blur(14px);-webkit-backdrop-filter:blur(14px);border:1px solid var(--card-border);box-shadow:var(--card-shadow);border-radius:18px;transition:all var(--trans-normal)}.app-container{width:100%;max-width:520px;display:flex;flex-direction:column;gap:14px;margin:0 auto}.btn{font-family:var(--font-main);font-size:.95rem;font-weight:600;border-radius:12px;padding:10px 18px;border:none;cursor:pointer;display:inline-flex;align-items:center;justify-content:center;gap:8px;transition:all var(--trans-fast);outline:none}.btn:focus-visible{outline:2px solid var(--accent-primary);outline-offset:2px}.btn-primary{background:linear-gradient(135deg,#6366f1,#8b5cf6);color:#fff;box-shadow:0 4px 14px #6366f159}.btn-primary:hover:not(:disabled){transform:translateY(-2px);box-shadow:0 6px 20px #6366f173}.btn-primary:active:not(:disabled){transform:translateY(0)}.btn-secondary{background:var(--btn-bg);color:var(--text-main);border:1px solid var(--card-border)}.btn-secondary:hover:not(:disabled){background:var(--btn-hover);transform:translateY(-2px)}.btn-sm{padding:6px 14px;font-size:.85rem;border-radius:9px}.btn-block{width:100%}.icon-btn{background:var(--btn-bg);border:1px solid var(--card-border);color:var(--text-main);border-radius:10px;width:36px;height:36px;display:flex;align-items:center;justify-content:center;font-size:1.1rem;cursor:pointer;transition:all var(--trans-fast)}.icon-btn:hover{background:var(--btn-hover);transform:scale(1.06)}.icon-btn:focus-visible{outline:2px solid var(--accent-primary);outline-offset:2px}.game-header{padding:14px 18px;display:flex;flex-direction:column;gap:12px}.header-top-row{display:flex;justify-content:space-between;align-items:center}.brand-group{display:flex;align-items:center;gap:10px}.brand-logo-icon{width:36px;height:36px;border-radius:10px;background:linear-gradient(135deg,#6366f1,#a855f7);display:flex;align-items:center;justify-content:center;color:#fff;font-weight:800;font-size:1.25rem;box-shadow:0 4px 12px #6366f166}.brand-title{font-size:1.2rem;font-weight:700;letter-spacing:-.02em;line-height:1.1}.brand-text{display:flex;flex-direction:column;gap:2px}.difficulty-badge{font-size:.7rem;font-weight:700;text-transform:uppercase;letter-spacing:.06em;padding:2px 7px;border-radius:6px;width:fit-content}.badge-easy{background:#10b98133;color:#10b981;border:1px solid rgba(16,185,129,.3)}.badge-medium{background:#3b82f633;color:#3b82f6;border:1px solid rgba(59,130,246,.3)}.badge-hard{background:#f59e0b33;color:#f59e0b;border:1px solid rgba(245,158,11,.3)}.badge-expert{background:#ef444433;color:#ef4444;border:1px solid rgba(239,68,68,.3)}.header-action-buttons{display:flex;align-items:center;gap:8px}.header-stats-row{display:flex;justify-content:space-between;align-items:center;padding-top:6px;border-top:1px solid var(--card-border)}.stat-card{display:flex;align-items:center;gap:8px}.stat-label{font-size:.8rem;color:var(--text-muted);font-weight:600;text-transform:uppercase;letter-spacing:.04em}.hearts-display{display:flex;gap:3px;font-size:1.15rem}.heart-icon{display:inline-block;transition:transform .3s ease}.heart-lost{opacity:.45;filter:grayscale(1)}.timer-display-group{display:flex;align-items:center;gap:6px;background:var(--btn-bg);padding:4px 10px;border-radius:9px;border:1px solid var(--card-border)}.timer-text{font-family:monospace;font-weight:700;font-size:1rem;letter-spacing:.05em}.timer-pause-btn{background:none;border:none;cursor:pointer;font-size:.95rem;padding:0 2px;display:flex;align-items:center;opacity:.8;transition:transform var(--trans-fast)}.timer-pause-btn:hover{opacity:1;transform:scale(1.15)}.modal-backdrop{position:fixed;top:0;right:0;bottom:0;left:0;background:var(--modal-backdrop);backdrop-filter:blur(8px);-webkit-backdrop-filter:blur(8px);display:flex;align-items:center;justify-content:center;padding:16px;z-index:999;animation:modalFadeIn .25s ease-out}.modal-container{width:100%;max-width:440px;max-height:90vh;overflow-y:auto;padding:24px;animation:modalScaleUp .3s cubic-bezier(.175,.885,.32,1.275)}@keyframes modalFadeIn{0%{opacity:0}to{opacity:1}}@keyframes modalScaleUp{0%{transform:scale(.92) translateY(10px);opacity:0}to{transform:scale(1) translateY(0);opacity:1}}.modal-header{display:flex;align-items:center;justify-content:space-between;margin-bottom:16px}.modal-title{font-size:1.35rem;font-weight:700}.modal-close-btn{background:var(--btn-bg);border:1px solid var(--card-border);color:var(--text-muted);width:32px;height:32px;border-radius:8px;cursor:pointer;display:flex;align-items:center;justify-content:center;font-size:1rem;transition:all var(--trans-fast)}.modal-close-btn:hover{color:var(--text-main);background:var(--btn-hover)}.modal-actions-row{display:flex;gap:12px;margin-top:20px}.modal-actions-row .btn{flex:1}.confetti-canvas{position:fixed;top:0;right:0;bottom:0;left:0;pointer-events:none;z-index:998}.sudoku-board-container{position:relative;width:100%;aspect-ratio:1 / 1;padding:8px;display:flex;align-items:center;justify-content:center;-webkit-user-select:none;user-select:none;touch-action:manipulation}.sudoku-grid{display:grid;grid-template-columns:repeat(9,1fr);grid-template-rows:repeat(9,1fr);width:100%;height:100%;border:2.5px solid var(--grid-thick-border);border-radius:12px;overflow:hidden;background:var(--grid-thick-border);gap:1px}.sudoku-cell{position:relative;background:var(--cell-bg);display:flex;align-items:center;justify-content:center;font-size:clamp(1.2rem,5.2vw,2rem);font-weight:600;cursor:pointer;outline:none;transition:background var(--trans-fast),transform var(--trans-fast)}.sudoku-cell:hover{background:var(--cell-hover)}.sudoku-cell.border-left-thick{border-left:2px solid var(--grid-thick-border)}.sudoku-cell.border-top-thick{border-top:2px solid var(--grid-thick-border)}.sudoku-cell.cell-given{color:var(--cell-given-color);font-weight:800}.sudoku-cell.cell-user{color:var(--cell-user-color);font-weight:600}.sudoku-cell.cell-highlighted{background:var(--cell-highlight)}.sudoku-cell.cell-same-number{background:var(--cell-same-num);font-weight:700}.sudoku-cell.cell-selected{background:var(--cell-selected)!important;color:var(--cell-selected-text)!important;box-shadow:var(--cell-selected-glow);z-index:2;border-radius:4px}.sudoku-cell.cell-conflict{background:var(--cell-conflict-bg)!important;color:var(--cell-conflict-text)!important;box-shadow:inset 0 0 0 2px var(--accent-error)}.sudoku-cell.cell-pop{animation:cellPop .3s cubic-bezier(.175,.885,.32,1.275)}@keyframes cellPop{0%{transform:scale(.65);opacity:.7}50%{transform:scale(1.2)}to{transform:scale(1);opacity:1}}.sudoku-cell.cell-shake{animation:cellShake .4s ease-in-out}@keyframes cellShake{0%,to{transform:translate(0)}20%,60%{transform:translate(-6px)}40%,80%{transform:translate(6px)}}@keyframes victoryWave{0%{transform:scale(1)}50%{transform:scale(1.12) translateY(-4px);filter:brightness(1.25)}to{transform:scale(1)}}.board-won .sudoku-cell{animation:victoryWave 1s ease-in-out infinite alternate}.cell-notes-grid{display:grid;grid-template-columns:repeat(3,1fr);grid-template-rows:repeat(3,1fr);width:90%;height:90%;pointer-events:none}.note-digit{display:flex;align-items:center;justify-content:center;font-size:clamp(.55rem,2vw,.75rem);font-weight:600;color:var(--note-color);line-height:1}.note-hidden{visibility:hidden}.board-pause-overlay{position:absolute;top:0;right:0;bottom:0;left:0;background:var(--modal-backdrop);backdrop-filter:blur(12px);-webkit-backdrop-filter:blur(12px);border-radius:16px;display:flex;align-items:center;justify-content:center;z-index:10;animation:modalFadeIn .2s ease-out}.pause-dialog{text-align:center;padding:24px;max-width:280px;display:flex;flex-direction:column;align-items:center;gap:12px}.pause-icon{font-size:2.2rem}.pause-dialog h3{font-size:1.25rem;font-weight:700}.pause-dialog p{font-size:.85rem;color:var(--text-muted)}.numpad-container{display:grid;grid-template-columns:repeat(9,1fr);gap:6px;padding:10px 12px}.numpad-btn{background:var(--btn-bg);border:1px solid var(--card-border);color:var(--text-main);border-radius:12px;display:flex;flex-direction:column;align-items:center;justify-content:center;padding:8px 0;cursor:pointer;transition:all var(--trans-fast);-webkit-user-select:none;user-select:none;touch-action:manipulation;outline:none}.numpad-btn:hover:not(:disabled){background:var(--btn-hover);transform:translateY(-2px)}.numpad-btn:active:not(:disabled){transform:translateY(0)}.numpad-btn:focus-visible{outline:2px solid var(--accent-primary);outline-offset:2px}.numpad-digit{font-size:clamp(1.1rem,4vw,1.45rem);font-weight:700;line-height:1.1}.numpad-badge{font-size:.68rem;font-weight:600;color:var(--text-dim);margin-top:2px}.numpad-completed{opacity:.35;cursor:not-allowed;filter:grayscale(1)}.numpad-completed .numpad-badge{color:var(--accent-success);font-weight:700}.game-controls{display:grid;grid-template-columns:repeat(4,1fr);gap:8px;padding:10px 14px}.control-btn{position:relative;background:var(--btn-bg);border:1px solid var(--card-border);color:var(--text-main);border-radius:12px;display:flex;flex-direction:column;align-items:center;justify-content:center;padding:8px 4px;gap:4px;cursor:pointer;transition:all var(--trans-fast);-webkit-user-select:none;user-select:none;touch-action:manipulation;outline:none}.control-btn:hover:not(:disabled){background:var(--btn-hover);transform:translateY(-2px)}.control-btn:active:not(:disabled){transform:translateY(0)}.control-btn:disabled{opacity:.4;cursor:not-allowed}.control-btn-active{background:linear-gradient(135deg,#6366f166,#a855f766)!important;border-color:var(--accent-primary)!important;box-shadow:0 0 14px #6366f159}.control-icon{font-size:1.25rem}.control-label{font-size:.78rem;font-weight:600}.control-status-pill{font-size:.62rem;font-weight:700;padding:1px 6px;border-radius:10px;text-transform:uppercase;letter-spacing:.04em}.pill-on{background:var(--accent-primary);color:#fff}.pill-off{background:#94a3b833;color:var(--text-dim)}.control-badge{position:absolute;top:4px;right:6px;background:var(--accent-primary);color:#fff;font-size:.65rem;font-weight:700;width:16px;height:16px;border-radius:50%;display:flex;align-items:center;justify-content:center}.how-to-play-content{display:flex;flex-direction:column;gap:16px;font-size:.92rem;line-height:1.5}.rules-section h3{font-size:1.05rem;font-weight:700;margin-bottom:8px;color:var(--accent-primary)}.rules-list{padding-left:20px;display:flex;flex-direction:column;gap:6px}.shortcuts-table{display:flex;flex-direction:column;gap:8px;background:var(--btn-bg);padding:12px;border-radius:12px;border:1px solid var(--card-border)}.shortcut-row{display:flex;align-items:center;justify-content:space-between;gap:10px;font-size:.85rem}.key-chip{background:var(--card-bg);border:1px solid var(--card-border);padding:2px 7px;border-radius:6px;font-family:monospace;font-weight:700;box-shadow:0 1px 3px #0000001a}.shortcut-desc{color:var(--text-muted)}.win-modal-content{text-align:center;display:flex;flex-direction:column;align-items:center;gap:14px}.win-trophy-badge{font-size:3.5rem;animation:trophyFloat 2s ease-in-out infinite alternate}@keyframes trophyFloat{0%{transform:translateY(0) scale(1)}to{transform:translateY(-8px) scale(1.08)}}.win-title{font-size:1.6rem;font-weight:800;letter-spacing:-.02em}.win-subtitle{color:var(--text-muted);font-size:.95rem}.new-record-banner{background:linear-gradient(135deg,#f59e0b,#ef4444);color:#fff;font-weight:800;padding:6px 14px;border-radius:10px;font-size:.82rem;letter-spacing:.05em;box-shadow:0 4px 12px #f59e0b66;animation:cellPop .4s ease-out}.win-stats-grid{display:grid;grid-template-columns:1fr 1fr;gap:10px;width:100%}.win-stat-box{background:var(--btn-bg);border:1px solid var(--card-border);border-radius:12px;padding:10px;display:flex;flex-direction:column;gap:4px}.win-stat-label{font-size:.75rem;color:var(--text-muted);font-weight:600;text-transform:uppercase}.win-stat-value{font-size:1.25rem;font-weight:800}.game-over-content{text-align:center;display:flex;flex-direction:column;align-items:center;gap:14px}.game-over-icon{font-size:3.2rem}.game-over-title{font-size:1.6rem;font-weight:800;color:var(--accent-error)}.game-over-desc{color:var(--text-muted);font-size:.95rem}.game-over-stats{font-size:.9rem;color:var(--text-dim)}.new-game-menu-content{display:flex;flex-direction:column;gap:14px}.continue-card{padding:14px;background:linear-gradient(135deg,#6366f140,#06b6d433);border:1px solid var(--accent-primary);display:flex;flex-direction:column;gap:10px}.continue-card-header{display:flex;justify-content:space-between;align-items:center}.continue-badge{font-size:.8rem;font-weight:700;color:var(--accent-primary);text-transform:uppercase;letter-spacing:.04em}.continue-diff{font-size:.75rem;font-weight:800;background:var(--accent-primary);color:#fff;padding:2px 8px;border-radius:6px}.continue-card-body{display:flex;gap:20px;font-size:.9rem;color:var(--text-muted)}.continue-btn{margin-top:4px}.difficulty-selection-heading h3{font-size:1.15rem;font-weight:700}.difficulty-selection-heading p{font-size:.82rem;color:var(--text-muted)}.difficulty-grid{display:grid;grid-template-columns:1fr 1fr;gap:10px}.difficulty-card{background:var(--btn-bg);border:1px solid var(--card-border);border-radius:14px;padding:12px;text-align:left;cursor:pointer;transition:all var(--trans-fast);display:flex;flex-direction:column;gap:6px;color:var(--text-main)}.difficulty-card:hover{background:var(--btn-hover);border-color:var(--accent-primary);transform:translateY(-2px)}.diff-card-header{display:flex;justify-content:space-between;align-items:center}.diff-title{font-weight:800;font-size:1.05rem}.diff-clues{font-size:.7rem;color:var(--text-dim);font-weight:600}.diff-desc{font-size:.78rem;color:var(--text-muted);line-height:1.3;flex-grow:1}.diff-best{font-size:.72rem;color:var(--text-dim);display:flex;justify-content:space-between;align-items:center;padding-top:6px;border-top:1px solid var(--card-border)}.diff-best strong{color:var(--text-main)}.modal-cancel-row{margin-top:6px}@media (max-width: 480px){body{padding:8px 6px}.app-container{gap:10px}.game-header{padding:10px 12px;gap:8px}.brand-title{font-size:1.05rem}.brand-logo-icon{width:32px;height:32px;font-size:1.1rem}.icon-btn{width:32px;height:32px;font-size:1rem}.numpad-container{gap:4px;padding:8px}.numpad-btn{padding:6px 0;border-radius:8px}.game-controls{gap:6px;padding:8px 10px}.difficulty-grid{grid-template-columns:1fr}}