:root{--bg-color: linear-gradient(135deg, #667eea 0%, #764ba2 100%);--grid-bg: rgba(255, 255, 255, .1);--tile-bg: rgba(255, 255, 255, .2);--text-color: #ffffff;--text-light: #ffffff;--shadow: rgba(0, 0, 0, .2);--tile-2: url(https://img.icons8.com/color/96/cat.png) center/contain;--tile-4: url(https://img.icons8.com/color/96/dog.png) center/contain;--tile-8: url(https://img.icons8.com/color/96/cat-head.png) center/contain;--tile-16: url(https://img.icons8.com/color/96/dog-face.png) center/contain;--tile-32: url(https://img.icons8.com/color/96/cat-head.png) center/contain;--tile-64: url(https://img.icons8.com/color/96/dog-head.png) center/contain;--tile-128: url(https://img.icons8.com/color/96/cat-sitting.png) center/contain;--tile-256: url(https://img.icons8.com/color/96/dog-sitting.png) center/contain;--tile-512: url(https://img.icons8.com/color/96/cat-walking.png) center/contain;--tile-1024: url(https://img.icons8.com/color/96/dog-walking.png) center/contain;--tile-2048: url(https://img.icons8.com/color/96/cat-and-dog.png) center/contain;--grid-size: 400px;--tile-size: 90px;--tile-margin: 5px;--border-radius: 6px;--font-size-large: 55px;--font-size-medium: 45px;--font-size-small: 35px}*{margin:0;padding:0;box-sizing:border-box}body{font-family:Arial,sans-serif;background:transparent;color:var(--text-color);display:flex;justify-content:center;align-items:flex-start;min-height:100vh;padding:20px 0;overflow-y:auto;position:relative;z-index:1}#app{text-align:center;padding:20px;position:relative;z-index:2}.game-header{margin-bottom:30px}.game-title{font-size:80px;font-weight:700;color:var(--text-color);margin-bottom:20px;text-shadow:2px 2px 8px rgba(0,0,0,.3);background:linear-gradient(135deg,#ffffff 0%,#e0e6ff 100%);-webkit-background-clip:text;-webkit-text-fill-color:transparent;background-clip:text}.game-info{display:flex;justify-content:space-between;align-items:center;margin-bottom:20px;max-width:var(--grid-size);margin-left:auto;margin-right:auto}.score-container{background:var(--grid-bg);-webkit-backdrop-filter:blur(10px);backdrop-filter:blur(10px);border:1px solid rgba(255,255,255,.2);padding:15px 25px;border-radius:var(--border-radius);color:var(--text-light);min-width:120px;box-shadow:0 4px 16px #0000001a}.score-title{font-size:14px;text-transform:uppercase;margin-bottom:5px}.score-value{font-size:24px;font-weight:700}.game-controls{margin-bottom:20px}.new-game-btn{background:linear-gradient(135deg,#667eea 0%,#764ba2 100%);color:var(--text-light);border:1px solid rgba(255,255,255,.3);padding:15px 30px;border-radius:var(--border-radius);font-size:18px;font-weight:700;cursor:pointer;transition:all .3s ease;box-shadow:0 4px 16px #0003;-webkit-backdrop-filter:blur(10px);backdrop-filter:blur(10px)}.new-game-btn:hover{background:linear-gradient(135deg,#5a6fd8 0%,#6a4190 100%);transform:translateY(-2px);box-shadow:0 8px 24px #0000004d}.new-game-btn:active{transform:translateY(0)}.ai-complete-btn{background:linear-gradient(135deg,#00b894 0%,#00a085 100%);color:var(--text-light);border:1px solid rgba(255,255,255,.3);padding:15px 30px;border-radius:var(--border-radius);font-size:18px;font-weight:700;cursor:pointer;transition:all .3s ease;box-shadow:0 4px 16px #0003;-webkit-backdrop-filter:blur(10px);backdrop-filter:blur(10px);margin-left:10px}.sound-btn{margin-left:10px}.ai-complete-btn:hover{background:linear-gradient(135deg,#00a085 0%,#008f76 100%);transform:translateY(-2px);box-shadow:0 8px 24px #0000004d}.ai-complete-btn:active{transform:translateY(0)}.ai-complete-btn:disabled{background:linear-gradient(135deg,#636e72 0%,#2d3436 100%);cursor:not-allowed;transform:none;opacity:.6}.game-container{position:relative;background:var(--grid-bg);-webkit-backdrop-filter:blur(10px);backdrop-filter:blur(10px);border:1px solid rgba(255,255,255,.2);border-radius:var(--border-radius);padding:10px;box-shadow:0 8px 32px var(--shadow);animation:containerGlow 4s ease-in-out infinite;z-index:2}@keyframes containerGlow{0%,to{box-shadow:0 8px 32px var(--shadow)}50%{box-shadow:0 8px 32px var(--shadow),0 0 20px #667eea4d}}.game-grid{display:grid;grid-template-columns:repeat(4,1fr);grid-template-rows:repeat(4,1fr);gap:var(--tile-margin);width:var(--grid-size);height:var(--grid-size)}.grid-cell{background:var(--tile-bg);-webkit-backdrop-filter:blur(5px);backdrop-filter:blur(5px);border:1px solid rgba(255,255,255,.1);border-radius:var(--border-radius);display:flex;justify-content:center;align-items:center;font-size:var(--font-size-large);font-weight:700;color:var(--text-color);transition:all .15s ease}.tile{position:absolute;width:var(--tile-size);height:var(--tile-size);border-radius:var(--border-radius);display:flex;justify-content:center;align-items:center;font-weight:700;color:var(--text-light);transition:all .15s ease;animation:tile-appear .2s ease;box-shadow:0 4px 16px #0003;border:1px solid rgba(255,255,255,.3);background-size:cover;background-position:center;background-repeat:no-repeat;text-shadow:2px 2px 4px rgba(0,0,0,.8),-1px -1px 2px rgba(255,255,255,.8)}.tile-2{background:var(--tile-2);font-size:var(--font-size-large)}.tile-4{background:var(--tile-4);font-size:var(--font-size-large)}.tile-8{background:var(--tile-8);font-size:var(--font-size-large)}.tile-16{background:var(--tile-16);font-size:var(--font-size-medium)}.tile-32{background:var(--tile-32);font-size:var(--font-size-medium)}.tile-64{background:var(--tile-64);font-size:var(--font-size-medium)}.tile-128{background:var(--tile-128);font-size:var(--font-size-small)}.tile-256{background:var(--tile-256);font-size:var(--font-size-small)}.tile-512{background:var(--tile-512);font-size:var(--font-size-small)}.tile-1024{background:var(--tile-1024);font-size:25px}.tile-2048{background:var(--tile-2048);font-size:25px}.tile-merged{animation:tile-merge .2s ease}@keyframes tile-appear{0%{opacity:0;transform:scale(0)}to{opacity:1;transform:scale(1)}}@keyframes tile-merge{0%{transform:scale(1)}50%{transform:scale(1.2)}to{transform:scale(1)}}.game-over{position:absolute;top:0;left:0;right:0;bottom:0;background:rgba(238,228,218,.9);display:flex;flex-direction:column;justify-content:center;align-items:center;border-radius:var(--border-radius);z-index:10}.game-over h2{font-size:48px;margin-bottom:20px;color:var(--text-color)}.game-over p{font-size:18px;margin-bottom:30px;color:var(--text-color)}.game-instructions{margin-top:40px;color:var(--text-color);font-size:16px;line-height:1.6;max-width:var(--grid-size);margin-left:auto;margin-right:auto;text-align:center;padding:20px;background:rgba(255,255,255,.1);-webkit-backdrop-filter:blur(10px);backdrop-filter:blur(10px);border:1px solid rgba(255,255,255,.2);border-radius:var(--border-radius);box-shadow:0 4px 16px #0000001a}.game-instructions h3{margin-bottom:15px;font-size:22px;font-weight:700;color:var(--text-color)}.game-instructions p{margin-bottom:10px}@media (max-width: 600px){:root{--grid-size: 300px;--tile-size: 65px;--font-size-large: 40px;--font-size-medium: 35px;--font-size-small: 25px}.game-title{font-size:60px}.game-info{flex-direction:column;gap:15px}.game-container{width:calc(var(--grid-size) + var(--tile-margin) * 4);margin:0 auto}.game-instructions{margin-top:30px;padding:15px;font-size:14px}.game-instructions h3{font-size:18px}.new-game-btn,.ai-complete-btn{padding:12px 24px;font-size:16px}}@media (max-width: 400px){:root{--grid-size: 280px;--tile-size: 60px;--font-size-large: 35px;--font-size-medium: 30px;--font-size-small: 20px}.game-title{font-size:50px}.game-container{width:var(--grid-size + --tile-margin * 4);margin:0 auto}.score-container{padding:10px 20px;min-width:100px}.score-value{font-size:20px}.sound-btn{margin-left:0;margin-top:10px}}.mobile-instructions{display:none;background:linear-gradient(135deg,rgba(102,126,234,.9),rgba(118,75,162,.9));-webkit-backdrop-filter:blur(10px);backdrop-filter:blur(10px);border:1px solid rgba(255,255,255,.2);border-radius:15px;padding:15px;margin-top:15px;color:var(--text-light);text-align:center;box-shadow:0 8px 32px var(--shadow);max-width:400px;width:100%}.mobile-instructions h3{margin:0 0 10px;font-size:16px;font-weight:700;color:#fff}.mobile-instructions p{margin:5px 0;font-size:14px;line-height:1.4}.mobile-instructions .gesture{display:inline-block;background:rgba(255,255,255,.2);border-radius:8px;padding:5px 10px;margin:2px;font-weight:700;font-size:12px}.virtual-controls{display:none;margin-top:20px;text-align:center}.virtual-controls .control-row{display:flex;justify-content:center;align-items:center;margin:5px 0}.virtual-btn{width:60px;height:60px;margin:5px;border:none;border-radius:15px;background:linear-gradient(135deg,rgba(102,126,234,.9),rgba(118,75,162,.9));-webkit-backdrop-filter:blur(10px);backdrop-filter:blur(10px);border:1px solid rgba(255,255,255,.2);color:#fff;font-size:24px;font-weight:700;cursor:pointer;transition:all .2s ease;box-shadow:0 4px 16px #0003;user-select:none;-webkit-user-select:none;-webkit-touch-callout:none}.virtual-btn:active{transform:scale(.95);box-shadow:0 2px 8px #0000004d}.virtual-btn.up,.virtual-btn.down,.virtual-btn.left,.virtual-btn.right{font-size:20px}@media (max-width: 600px){.game-instructions{display:none}.mobile-instructions{display:block;margin-left:auto;margin-right:auto}.virtual-controls{display:block}}.tile{background-blend-mode:overlay}.tile-2{filter:brightness(1.1) contrast(1.1)}.tile-4{filter:brightness(1.05) saturate(1.2)}.tile-8{filter:brightness(1.1) hue-rotate(10deg)}.tile-16{filter:brightness(1.05) saturate(1.3)}.tile-32{filter:brightness(1.1) contrast(1.05)}.tile-64{filter:brightness(1.05) saturate(1.4)}.tile-128{filter:brightness(1.1) hue-rotate(-10deg)}.tile-256{filter:brightness(1.05) saturate(1.5)}.tile-512{filter:brightness(1.1) contrast(1.1)}.tile-1024{filter:brightness(1.05) saturate(1.6)}.tile-2048{filter:brightness(1.1) hue-rotate(20deg)}.tile:hover{transform:scale(1.05);box-shadow:0 6px 20px #0000004d;z-index:2}.tile-merged{animation:tile-merge .3s ease;filter:brightness(1.2) saturate(1.5)}@keyframes tile-merge{0%{transform:scale(1);filter:brightness(1) saturate(1)}50%{transform:scale(1.3);filter:brightness(1.4) saturate(1.8)}to{transform:scale(1);filter:brightness(1.2) saturate(1.5)}}.tile{background-blend-mode:multiply;filter:drop-shadow(0 2px 4px rgba(0,0,0,.3))}.tile-2{background-color:#ffb6c14d}.tile-4{background-color:#add8e64d}.tile-8{background-color:#ffdab94d}.tile-16{background-color:#dda0dd4d}.tile-32{background-color:#90ee904d}.tile-64{background-color:#ffe4c44d}.tile-128{background-color:#b0e0e64d}.tile-256{background-color:#ffc0cb4d}.tile-512{background-color:#f0f8ff4d}.tile-1024{background-color:#fff0f54d}.tile-2048{background-color:#f5f5dc4d}.tile{background-blend-mode:soft-light;filter:drop-shadow(0 3px 6px rgba(0,0,0,.2));border:2px solid rgba(255,255,255,.4)}.tile-2{background-color:#ffb6c166}.tile-4{background-color:#add8e666}.tile-8{background-color:#ffdab966}.tile-16{background-color:#dda0dd66}.tile-32{background-color:#90ee9066}.tile-64{background-color:#ffe4c466}.tile-128{background-color:#b0e0e666}.tile-256{background-color:#ffc0cb66}.tile-512{background-color:#f0f8ff66}.tile-1024{background-color:#fff0f566}.tile-2048{background-color:#f5f5dc66}@keyframes anime-tile-appear{0%{opacity:0;transform:scale(0) rotate(-180deg)}50%{opacity:.7;transform:scale(1.1) rotate(-90deg)}to{opacity:1;transform:scale(1) rotate(0)}}.tile{animation:anime-tile-appear .4s ease-out}@keyframes anime-tile-merge{0%{transform:scale(1);filter:brightness(1) saturate(1)}25%{transform:scale(1.2) rotate(5deg);filter:brightness(1.3) saturate(1.5)}50%{transform:scale(1.4) rotate(-5deg);filter:brightness(1.5) saturate(1.8)}75%{transform:scale(1.2) rotate(5deg);filter:brightness(1.3) saturate(1.5)}to{transform:scale(1);filter:brightness(1.2) saturate(1.3)}}.tile-merged{animation:anime-tile-merge .5s ease-in-out}