:root{--primary-bg: linear-gradient(135deg, #667eea 0%, #764ba2 100%);--surface-bg: #ffffff;--surface-elevated: #f8f9fa;--surface-border: #e1e8ed;--text-primary: #1a202c;--text-secondary: #718096;--text-inverse: #ffffff;--accent-primary: #667eea;--accent-primary-hover: #5568d3;--accent-success: #48bb78;--accent-success-hover: #38a169;--accent-danger: #f56565;--accent-danger-hover: #e53e3e;--accent-warning: #ed8936;--accent-info: #4299e1;--shadow-sm: 0 1px 3px 0 rgba(0, 0, 0, .1), 0 1px 2px 0 rgba(0, 0, 0, .06);--shadow-md: 0 4px 6px -1px rgba(0, 0, 0, .1), 0 2px 4px -1px rgba(0, 0, 0, .06);--shadow-lg: 0 10px 15px -3px rgba(0, 0, 0, .1), 0 4px 6px -2px rgba(0, 0, 0, .05);--shadow-highlight: 0 0 0 3px rgba(102, 126, 234, .4);--block-size: clamp(2rem, 10vw, 3rem);--block-gap: .25rem;--stack-border-width: 2px;--stack-border-color: var(--surface-border);--stack-bg: var(--surface-elevated);--stack-padding: .25rem;--stack-gap: 1rem;--empty-slot-bg: transparent;--empty-slot-border: 1px dashed var(--surface-border);--block-red: #e53e3e;--block-orange: #dd6b20;--block-yellow: #d69e2e;--block-green: #38a169;--block-teal: #319795;--block-blue: #3182ce;--block-indigo: #5a67d8;--block-purple: #805ad5;--block-pink: #d53f8c;--block-brown: #975a16;--tile-min-size: 100px;--tile-border-radius: 8px;--tile-bg: #fff;--tile-border: 2px solid #ddd;--tile-shadow: 0 2px 4px rgba(0, 0, 0, .1);--tile-hover-shadow: 0 4px 8px rgba(0, 0, 0, .2);--tile-locked-opacity: .5;--tile-completed-color: #4caf50}body{margin:0;padding:0;font-family:-apple-system,BlinkMacSystemFont,Segoe UI,Roboto,Oxygen,Ubuntu,Cantarell,Fira Sans,Droid Sans,Helvetica Neue,sans-serif;-webkit-font-smoothing:antialiased;-moz-osx-font-smoothing:grayscale;background:var(--primary-bg);color:var(--text-primary);min-height:100vh}#app{min-height:100vh;display:flex;flex-direction:column}.game-container{display:flex;flex-direction:row;flex-wrap:wrap;gap:var(--stack-gap);align-items:flex-end;justify-content:center;padding:2rem 1.5rem;touch-action:none;-webkit-tap-highlight-color:transparent;background:var(--surface-bg);border-radius:0;margin:0 1rem;min-height:300px}.stack{display:flex;flex-direction:column-reverse;border:var(--stack-border-width) solid var(--stack-border-color);border-top:none;background:linear-gradient(to right,rgba(0,0,0,.03) 0%,transparent 20%,transparent 80%,rgba(0,0,0,.03) 100%),var(--stack-bg);padding:var(--stack-padding);gap:var(--block-gap);border-radius:0 0 12px 12px;box-shadow:var(--shadow-sm),inset 1px 0 #fff9,inset -1px 0 #fff9;transition:all .2s ease-in-out}.block{width:var(--block-size);height:var(--block-size);position:relative;border-radius:6px;box-shadow:var(--shadow-sm),inset 0 1px #ffffff59,inset 0 -2px 4px #00000026;background-image:linear-gradient(135deg,rgba(255,255,255,.3) 0%,rgba(255,255,255,.05) 40%,transparent 60%,rgba(0,0,0,.1) 100%);background-blend-mode:overlay;transition:transform .15s ease-out,box-shadow .15s ease-out;cursor:pointer;will-change:transform}.block:active{transform:scale(.95);box-shadow:var(--shadow-md)}.block:hover{transform:translateY(-2px);box-shadow:var(--shadow-md)}.stack:active{border-color:var(--accent-primary);box-shadow:var(--shadow-md)}.block--selected{outline:3px solid var(--accent-primary);outline-offset:2px;box-shadow:var(--shadow-highlight);z-index:10;transform:scale(1.05)}.block--immovable{animation:shake .3s ease-in-out}@keyframes shake{0%,to{transform:translate(0)}25%{transform:translate(-5px)}50%{transform:translate(5px)}75%{transform:translate(-5px)}}.stack--valid-target{background-color:#48bb7814;border-color:var(--accent-success);border-style:dashed;box-shadow:0 0 0 3px #48bb7833,inset 1px 0 #48bb7826,inset -1px 0 #48bb7826;transform:scale(1.02)}.stack--completed{border-color:var(--accent-success);box-shadow:0 0 12px #48bb784d,0 0 4px #48bb7833,inset 1px 0 #fff9,inset -1px 0 #fff9}.empty-slot{width:var(--block-size);height:var(--block-size);background:var(--empty-slot-bg);border:var(--empty-slot-border);box-sizing:border-box;border-radius:4px;opacity:.3}.level-select-container{display:flex;flex-direction:column;align-items:center;padding:1rem;max-width:600px;margin:0 auto}.level-select-back-button{align-self:flex-start;padding:.5rem 1rem;margin-bottom:1rem;background:none;border:var(--tile-border);border-radius:4px;cursor:pointer;font-size:1rem;min-height:44px;min-width:44px}.level-select-back-button:hover{background-color:var(--stack-bg)}.level-select-back-button:active{transform:scale(.97)}.level-select-grid{display:grid;grid-template-columns:repeat(4,1fr);gap:1rem;width:100%}.level-tile{display:flex;flex-direction:column;align-items:center;justify-content:center;min-width:var(--tile-min-size);min-height:var(--tile-min-size);background:var(--tile-bg);border:var(--tile-border);border-radius:var(--tile-border-radius);box-shadow:var(--tile-shadow);padding:.5rem;position:relative;-webkit-tap-highlight-color:transparent}.level-tile--locked{opacity:var(--tile-locked-opacity);cursor:default;pointer-events:none}.level-tile--unlocked{cursor:pointer}.level-tile--unlocked:hover{box-shadow:var(--tile-hover-shadow);transform:translateY(-2px)}.level-tile--unlocked:active{transform:scale(.97);box-shadow:var(--tile-shadow)}.level-tile--completed{border-color:var(--tile-completed-color);cursor:pointer}.level-tile--completed:hover{box-shadow:var(--tile-hover-shadow);transform:translateY(-2px)}.level-tile--completed:active{transform:scale(.97);box-shadow:var(--tile-shadow)}.level-tile__number{font-size:1.5rem;font-weight:700;line-height:1;margin-bottom:.25rem}.level-tile__difficulty{font-size:.75rem;color:#888;text-transform:capitalize}.level-tile__status{position:absolute;top:.25rem;right:.25rem;font-size:.875rem;line-height:1}.level-tile--completed .level-tile__status{color:var(--tile-completed-color)}.level-tile--locked .level-tile__status{color:#999}.game-header{display:flex;justify-content:space-between;align-items:center;padding:1rem 1.5rem;background:var(--surface-bg);border-radius:16px 16px 0 0;margin:1rem 1rem 0;box-shadow:var(--shadow-sm);border-bottom:1px solid var(--surface-border)}.level-indicator{font-size:1.25rem;font-weight:700;color:var(--text-primary);letter-spacing:-.01em}.move-counter{font-size:.9375rem;font-weight:600;color:var(--text-secondary);background:var(--surface-elevated);padding:.25rem .75rem;border-radius:20px;border:1px solid var(--surface-border)}.game-footer{display:flex;justify-content:space-between;align-items:center;padding:.75rem 1.5rem;background:var(--surface-bg);border-radius:0 0 16px 16px;margin:0 1rem 1rem;box-shadow:var(--shadow-sm);border-top:1px solid var(--surface-border);gap:.75rem}.game-controls{display:flex;justify-content:center;align-items:center;padding:.5rem 1rem;gap:.5rem;background:var(--surface-bg);margin:0 1rem;border-left:1px solid var(--surface-border);border-right:1px solid var(--surface-border)}.reset-button,.back-button{padding:.625rem 1.5rem;font-size:1rem;color:var(--text-inverse);border:none;border-radius:8px;cursor:pointer;touch-action:manipulation;font-weight:600;transition:all .2s ease-in-out;box-shadow:var(--shadow-sm)}.reset-button{background-color:var(--accent-danger)}.reset-button:hover{background-color:var(--accent-danger-hover);box-shadow:var(--shadow-md);transform:translateY(-1px)}.reset-button:active{transform:scale(.98) translateY(0)}.back-button{background-color:#6c757d}.back-button:hover{background-color:#5a6268;box-shadow:var(--shadow-md);transform:translateY(-1px)}.back-button:active{transform:scale(.98)}.undo-button,.redo-button{padding:.625rem 1.25rem;font-size:.875rem;cursor:pointer;background-color:var(--accent-primary);color:var(--text-inverse);border:none;border-radius:8px;font-weight:600;transition:all .2s ease-in-out;box-shadow:var(--shadow-sm)}.undo-button:hover:not(:disabled),.redo-button:hover:not(:disabled){background-color:var(--accent-primary-hover);box-shadow:var(--shadow-md);transform:translateY(-1px)}.undo-button:active:not(:disabled),.redo-button:active:not(:disabled){transform:scale(.98) translateY(0)}.undo-button:disabled,.redo-button:disabled{background-color:var(--surface-border);color:var(--text-secondary);cursor:not-allowed;opacity:.5;box-shadow:none}@media(max-width:480px){:root{--stack-gap: .5rem;--stack-padding: .125rem;--block-gap: .125rem}.game-container{margin:0 .5rem;padding:1rem .5rem}.game-header{margin:.5rem .5rem 0;padding:.75rem 1rem;border-radius:12px 12px 0 0}.game-footer{margin:0 .5rem .5rem;padding:.625rem 1rem;border-radius:0 0 12px 12px}.game-controls{margin:0 .5rem;padding:.375rem .75rem;gap:.5rem;flex-wrap:wrap}.level-indicator{font-size:1rem}.move-counter{font-size:.875rem}.level-select-grid{grid-template-columns:repeat(2,1fr);gap:.75rem}.reset-button,.back-button{font-size:.875rem;padding:.5rem 1rem}.undo-button,.redo-button{font-size:.8125rem;padding:.5rem 1rem}}@media(min-width:481px)and (max-width:768px){.level-select-grid{grid-template-columns:repeat(3,1fr)}}.win-screen-overlay{position:fixed;top:0;left:0;width:100%;height:100%;background:#0009;display:flex;align-items:center;justify-content:center;z-index:100;animation:win-screen-fade-in .4s ease-out}@keyframes win-screen-fade-in{0%{opacity:0}to{opacity:1}}.win-screen-modal{background:#fff;border-radius:12px;padding:2rem;text-align:center;max-width:320px;width:90%;box-shadow:0 8px 32px #0000004d;animation:win-screen-modal-enter .4s cubic-bezier(.34,1.56,.64,1)}@keyframes win-screen-modal-enter{0%{opacity:0;transform:scale(.8) translateY(20px)}to{opacity:1;transform:scale(1) translateY(0)}}.win-screen-title{font-size:1.5rem;font-weight:700;color:#2d3436;margin:0 0 .5rem}.win-screen-stats{font-size:1rem;color:#636e72;margin:0 0 1.5rem}.win-screen-actions{display:flex;flex-direction:column;gap:.75rem}.win-screen-button{padding:.75rem 1.5rem;font-size:1rem;font-weight:500;border:none;border-radius:6px;cursor:pointer;transition:background-color .2s,transform .1s;color:#fff;background-color:#6c757d}.win-screen-button:hover{filter:brightness(.9)}.win-screen-button:active{transform:scale(.98)}.win-screen-button--primary{background-color:#4caf50}.win-screen-button--disabled{background-color:#ccc;cursor:not-allowed;opacity:.6}.win-screen-button--disabled:hover{filter:none}.dev-banner{position:fixed;bottom:0;left:0;right:0;background:#000000bf;color:#aaa;font:11px/1.4 monospace;padding:2px 8px;z-index:9999;pointer-events:none}.menu-container{display:flex;flex-direction:column;align-items:center;justify-content:center;min-height:80vh;padding:2rem 1rem;max-width:440px;margin:0 auto}.menu-title{font-size:3rem;font-weight:800;color:var(--text-inverse);margin-bottom:3rem;text-align:center;text-shadow:0 2px 10px rgba(0,0,0,.2);letter-spacing:-.02em;line-height:1.1}.menu-nav{display:flex;flex-direction:column;gap:1rem;width:100%;max-width:360px;background:var(--surface-bg);padding:2rem;border-radius:16px;box-shadow:var(--shadow-lg)}.menu-button{padding:1rem 1.5rem;font-size:1rem;font-weight:600;color:var(--text-inverse);background-color:var(--accent-success);border:none;border-radius:12px;cursor:pointer;touch-action:manipulation;transition:all .2s ease-in-out;width:100%;text-align:center;box-shadow:var(--shadow-sm)}.menu-button:hover{background-color:var(--accent-success-hover);box-shadow:var(--shadow-md);transform:translateY(-2px)}.menu-button:active{transform:scale(.98) translateY(0)}.menu-button--primary{padding:1.25rem 1.5rem;font-size:1.25rem;font-weight:700;background-color:var(--accent-primary);box-shadow:var(--shadow-md)}.menu-button--primary:hover{background-color:var(--accent-primary-hover);box-shadow:var(--shadow-lg);transform:translateY(-3px)}.menu-button--danger{background-color:var(--accent-danger);font-size:.875rem;padding:.75rem 1.5rem}.menu-button--danger:hover{background-color:var(--accent-danger-hover)}@media(max-width:480px){.menu-container{padding:1.5rem 1rem}.menu-title{font-size:2.25rem;margin-bottom:2rem}.menu-nav{max-width:100%;padding:1.5rem;gap:.875rem}.menu-button{font-size:.9375rem;padding:.875rem 1.25rem}.menu-button--primary{font-size:1.125rem;padding:1rem 1.25rem}.menu-button--danger{font-size:.8125rem;padding:.625rem 1rem}}