:root{color-scheme:dark;font-family:ui-sans-serif,system-ui,-apple-system,Segoe UI,Roboto,sans-serif;line-height:1.5}*{box-sizing:border-box}html,body,#root{margin:0;min-height:100vh;background:#0a0a0a;color:#fafafa;overflow:hidden;touch-action:none;user-select:none;-webkit-user-select:none}.shell{min-height:100vh;display:flex;flex-direction:column;align-items:center;justify-content:center;padding:1rem;gap:1rem}.header{display:flex;align-items:center;justify-content:space-between;width:100%;max-width:480px}.title{font-size:1.4rem;font-weight:700;letter-spacing:-.02em;background:linear-gradient(135deg,#f59e0b,#ef4444);-webkit-background-clip:text;-webkit-text-fill-color:transparent;background-clip:text}.score-box{display:flex;gap:1.2rem}.score-item{text-align:center}.score-label{font-size:.6rem;text-transform:uppercase;letter-spacing:.15em;color:#fff6}.score-value{font-size:1.3rem;font-weight:700;font-variant-numeric:tabular-nums}.board-wrap{position:relative;width:100%;max-width:480px;aspect-ratio:1}.board{width:100%;height:100%;display:grid;gap:3px;background:#ffffff0a;border-radius:12px;padding:3px;border:1px solid rgba(255,255,255,.08)}.cell{border-radius:6px;background:#ffffff08;display:flex;align-items:center;justify-content:center;font-weight:700;font-size:clamp(.7rem,2.5vw,1.2rem);transition:background .1s,transform .1s;position:relative}.cell.snake-head{transform:scale(1.05);z-index:2;box-shadow:0 0 12px #ffffff26}.cell.snake-body{opacity:.85}.cell.tile{animation:tilePop .2s ease-out}@keyframes tilePop{0%{transform:scale(.5);opacity:0}to{transform:scale(1);opacity:1}}.merge-anim{animation:merge .25s ease-out}@keyframes merge{0%{transform:scale(1.3)}50%{transform:scale(.9)}to{transform:scale(1)}}.overlay{position:absolute;top:0;right:0;bottom:0;left:0;background:#000000b3;-webkit-backdrop-filter:blur(4px);backdrop-filter:blur(4px);display:flex;flex-direction:column;align-items:center;justify-content:center;gap:1rem;border-radius:12px;z-index:10}.overlay h2{margin:0;font-size:1.6rem}.overlay p{margin:0;color:#ffffff80;font-size:.85rem}.btn{padding:.6rem 1.6rem;border:none;border-radius:8px;font-weight:600;font-size:.9rem;cursor:pointer;background:linear-gradient(135deg,#f59e0b,#ef4444);color:#fff;transition:transform .1s,opacity .2s}.btn:hover{opacity:.9}.btn:active{transform:scale(.96)}.instructions{color:#ffffff4d;font-size:.7rem;text-align:center;max-width:480px}