*{box-sizing:border-box;margin:0;padding:0}html,body{height:100%;background:var(--bg);color:var(--text);font-family:-apple-system,BlinkMacSystemFont,Segoe UI,Roboto,Helvetica,Arial,sans-serif;-webkit-font-smoothing:antialiased;overscroll-behavior:none;touch-action:manipulation}#app{min-height:100%;display:flex;align-items:center;justify-content:center;padding:16px}.game{width:min(92vw,460px);display:flex;flex-direction:column;gap:14px}.crumb{font-size:14px}.crumb a{color:var(--accent);text-decoration:none;font-weight:700}.crumb a:hover{text-decoration:underline}.topbar{display:flex;flex-wrap:wrap;align-items:center;justify-content:space-between;gap:12px}.title{font-size:clamp(40px,12vw,64px);font-weight:800;line-height:1;letter-spacing:-1px}.scores{display:flex;gap:8px}.score-box{background:var(--board-bg);color:var(--accent-text);border-radius:6px;padding:6px 14px;text-align:center;min-width:72px}.score-box .label{font-size:11px;text-transform:uppercase;letter-spacing:1px;opacity:.85;font-weight:700}.score-box .value{font-size:22px;font-weight:800;line-height:1.1}.controls{display:flex;align-items:center;justify-content:space-between;gap:10px}.how{font-size:13px;opacity:.85;flex:1}.how b{font-weight:700}.btn{background:var(--accent);color:var(--accent-text);border:none;border-radius:6px;padding:10px 16px;font-size:14px;font-weight:700;cursor:pointer;white-space:nowrap;transition:filter .12s ease}.btn:hover{filter:brightness(1.05)}.btn:active{filter:brightness(.95)}.board{--gap: clamp(8px, 2.5vw, 14px);--board: min(92vw, calc(100dvh - 210px) , 460px);--cell: calc((var(--board) - 5 * var(--gap)) / 4);position:relative;width:var(--board);height:var(--board);min-width:260px;min-height:260px;align-self:center;background:var(--board-bg);border-radius:8px;padding:var(--gap);touch-action:none}.grid{position:absolute;inset:var(--gap);display:grid;grid-template-columns:repeat(4,1fr);grid-template-rows:repeat(4,1fr);gap:var(--gap)}.grid .cell{background:var(--cell-bg);border-radius:6px}.tiles{position:absolute;inset:var(--gap)}.tile{position:absolute;width:var(--cell);height:var(--cell);border-radius:6px;display:flex;align-items:center;justify-content:center;font-weight:800;font-size:calc(var(--cell) * .48);background:#eee4da;color:#776e65;--tx: calc(var(--col) * (var(--cell) + var(--gap)));--ty: calc(var(--row) * (var(--cell) + var(--gap)));transform:translate(var(--tx),var(--ty));transition:transform .1s ease-in-out;will-change:transform}.tile.pop{animation:pop .14s ease}.tile.appear{animation:appear .14s ease}@keyframes pop{0%{transform:translate(var(--tx),var(--ty)) scale(1)}55%{transform:translate(var(--tx),var(--ty)) scale(1.2)}to{transform:translate(var(--tx),var(--ty)) scale(1)}}@keyframes appear{0%{opacity:0;transform:translate(var(--tx),var(--ty)) scale(.1)}70%{opacity:1;transform:translate(var(--tx),var(--ty)) scale(1.05)}to{opacity:1;transform:translate(var(--tx),var(--ty)) scale(1)}}.tile[data-v="2"]{background:#eee4da}.tile[data-v="4"]{background:#ede0c8}.tile[data-v="8"]{background:#f2b179;color:#f9f6f2}.tile[data-v="16"]{background:#f59563;color:#f9f6f2}.tile[data-v="32"]{background:#f67c5f;color:#f9f6f2}.tile[data-v="64"]{background:#f65e3b;color:#f9f6f2}.tile[data-v="128"]{background:#edcf72;color:#f9f6f2;font-size:calc(var(--cell) * .4)}.tile[data-v="256"]{background:#edcc61;color:#f9f6f2;font-size:calc(var(--cell) * .4)}.tile[data-v="512"]{background:#edc850;color:#f9f6f2;font-size:calc(var(--cell) * .4)}.tile[data-v="1024"]{background:#edc53f;color:#f9f6f2;font-size:calc(var(--cell) * .32)}.tile[data-v="2048"]{background:#edc22e;color:#f9f6f2;font-size:calc(var(--cell) * .32);box-shadow:0 0 24px #edc22eb3}.tile[data-big="1"]{background:#3c3a32;color:#f9f6f2;font-size:calc(var(--cell) * .28)}.overlay{position:absolute;inset:0;border-radius:8px;display:flex;flex-direction:column;align-items:center;justify-content:center;gap:16px;text-align:center;padding:20px;background:var(--overlay-bg);z-index:10;opacity:0;pointer-events:none;transition:opacity .22s ease}.overlay.show{opacity:1;pointer-events:auto}.overlay .msg{font-size:clamp(28px,9vw,44px);font-weight:800}.overlay.win .msg{color:#ed9a2e}.overlay .actions{display:flex;gap:10px}