:root{--game-accent:#4ade80;--game-accent-dark:#16a34a;--game-accent-soft:#14301f;--ink:#eef1f6;--ink-soft:#9aa4b5;--bg:#10131a;--panel:#1a1f2b;--panel-border:#2a3142;--good:#4ade80;--bad:#f87171;--radius:18px;--radius-small:12px;--shadow:0 4px 18px #00000059;--font:system-ui, -apple-system, "Segoe UI", Roboto, sans-serif;--tap-min:48px}*{box-sizing:border-box}html,body{margin:0;padding:0}body{font-family:var(--font);background:var(--bg);color:var(--ink);-webkit-font-smoothing:antialiased}button{font:inherit;color:inherit}.topbar{align-items:center;gap:.6rem;max-width:560px;margin:0 auto;padding:.7rem 1rem .3rem;display:flex}.topbar .back{color:var(--ink-soft);padding:.4rem .2rem;font-size:.95rem;text-decoration:none}.topbar .back:hover{color:var(--ink)}.topbar h1{text-align:center;flex:1;margin:0;font-size:1.25rem}.icon-btn{background:var(--panel);border:1px solid var(--panel-border);cursor:pointer;border-radius:12px;flex:none;justify-content:center;align-items:center;width:44px;height:44px;display:inline-flex}.icon-btn svg{width:22px;height:22px;stroke:var(--ink)}.settings-wrap{max-width:560px;margin:0 auto;padding:0 1rem}.settings-panel{background:var(--panel);border:1px solid var(--panel-border);border-radius:var(--radius);margin-top:.4rem;padding:.9rem 1rem}.settings-panel[hidden]{display:none}.setting-row{justify-content:space-between;align-items:center;gap:1rem;padding:.45rem 0;display:flex}.setting-row .lbl{font-size:1rem}.switch{border:1px solid var(--panel-border);cursor:pointer;background:#262c3d;border-radius:999px;flex:none;width:52px;height:30px;padding:0;position:relative}.switch:after{content:"";background:#cbd5e1;border-radius:50%;width:22px;height:22px;transition:transform .15s,background .15s;position:absolute;top:3px;left:3px}.switch[aria-checked=true]{background:var(--game-accent-dark)}.switch[aria-checked=true]:after{background:#fff;transform:translate(22px)}.seg{border:1px solid var(--panel-border);background:#262c3d;border-radius:999px;gap:2px;padding:3px;display:inline-flex}.seg button{color:var(--ink-soft);cursor:pointer;background:0 0;border:0;border-radius:999px;padding:.32rem .7rem;font-size:.92rem}.seg button[aria-pressed=true]{background:var(--game-accent-dark);color:#fff}.footer{text-align:center;color:var(--ink-soft);padding:1.2rem 1rem 1.6rem;font-size:.85rem;line-height:1.5}.footer a{color:var(--ink-soft)}.btn{background:var(--game-accent-dark);color:#fff;cursor:pointer;min-height:var(--tap-min);border:0;border-radius:12px;padding:.7rem 1.3rem;font-size:1rem;font-weight:600}.btn.secondary{background:var(--panel);border:1px solid var(--panel-border);color:var(--ink);font-weight:500}html[data-theme=halloween]{--bg:#160f1e;--panel:#221631;--panel-border:#3b2354;--ink:#f6ecdd;--ink-soft:#b39ecb;--game-accent:#fb923c;--game-accent-dark:#ea580c;--game-accent-soft:#2f1a08}html[data-theme=christmas]{--bg:#0c1a12;--panel:#12291a;--panel-border:#1e4630;--ink:#f2efe3;--ink-soft:#a9bfa5;--game-accent:#ef4444;--game-accent-dark:#b91c1c;--game-accent-soft:#2f0f0f}.season-banner{max-width:560px;margin:.6rem auto 0;padding:0 1rem}.season-banner-inner{background:var(--panel);border:1px solid var(--game-accent-dark);border-radius:var(--radius-small);align-items:center;gap:.6rem;padding:.55rem .8rem;font-size:.95rem;display:flex}.season-banner-main{color:inherit;font:inherit;text-align:left;cursor:pointer;background:0 0;border:0;flex:1;padding:.2rem 0}.season-banner-close{color:var(--ink-soft);cursor:pointer;background:0 0;border:0;flex:none;padding:.3rem;font-size:1.05rem;line-height:1}:root{--game-accent:#f59e0b;--game-accent-dark:#d97706;--game-accent-soft:#38270d}.wrap{max-width:560px;margin:0 auto;padding:.4rem 1rem 0}.score-row{align-items:center;gap:.6rem;margin:.4rem 0 .7rem;display:flex}.score-box{background:var(--panel);border:1px solid var(--panel-border);border-radius:var(--radius-small);color:var(--ink-soft);padding:.5rem .8rem;font-size:.95rem;position:relative}.score-box strong{color:var(--ink);margin-left:.25rem;font-size:1.1rem}.score-box .delta{color:var(--game-accent);font-size:.9rem;font-weight:700;position:absolute;top:-.55rem;right:.45rem}.score-row .actions{gap:.5rem;margin-left:auto;display:flex}.score-row .btn{white-space:nowrap;min-height:44px;padding:.5rem .9rem}@media (width<=480px){.score-row{gap:.45rem}.score-box{padding:.5rem .6rem}.score-row .btn{padding:.5rem .6rem;font-size:.95rem}}.btn[disabled]{opacity:.45;cursor:default}.board-wrap{width:min(100%,58vh,500px);margin:0 auto;position:relative}.board{border:1px solid var(--panel-border);aspect-ratio:1;touch-action:none;-webkit-user-select:none;user-select:none;background:#0b0e14;border-radius:14px;position:relative;overflow:hidden}.well{background:#1b2233;border-radius:8px;position:absolute;top:0;left:0}.tiles{position:absolute;inset:0}.tile{will-change:transform;transition:transform .11s ease-in-out;position:absolute;top:0;left:0}.tile-face{color:#776e65;background:#eee4da;border-radius:8px;justify-content:center;align-items:center;width:100%;height:100%;font-weight:700;display:flex;position:relative}.tile-icon{width:62%;height:62%;display:none}.tile-icon svg{width:100%;height:100%;display:block}html[data-theme=halloween] .tile-icon-halloween,html[data-theme=christmas] .tile-icon-christmas{display:block}html[data-theme=halloween] .tile-num,html[data-theme=christmas] .tile-num{color:#fff;background:#0a041473;border-radius:999px;padding:0 .36em;font-size:.34em;line-height:1.3;position:absolute;top:5%;left:6%}.tiles.no-anim .tile{transition:none}.tiles.no-anim .tile-face{animation:none}.tile-new .tile-face{animation:.15s .1s backwards spawn}.tile-merged .tile-face{animation:.16s .1s backwards pop}@keyframes spawn{0%{transform:scale(0)}to{transform:scale(1)}}@keyframes pop{0%{transform:scale(.9)}55%{transform:scale(1.18)}to{transform:scale(1)}}.tile-2{background:#eee4da}.tile-4{background:#ede0c8}.tile-8{color:#f9f6f2;background:#f2b179}.tile-16{color:#f9f6f2;background:#f59563}.tile-32{color:#f9f6f2;background:#f67c5f}.tile-64{color:#f9f6f2;background:#f65e3b}.tile-128{color:#f9f6f2;background:#edcf72}.tile-256{color:#f9f6f2;background:#edcc61}.tile-512{color:#f9f6f2;background:#edc850}.tile-1024{color:#f9f6f2;background:#edc53f}.tile-2048{color:#f9f6f2;background:#edc22e;box-shadow:0 0 18px #edc22e8c}.tile-super{color:#f9f6f2;background:#3c3a32}html[data-theme=halloween] .board{background:#100818}html[data-theme=halloween] .well{background:#251539}html[data-theme=halloween] .tile-face{color:#e0e7ff;background:#312e81}html[data-theme=halloween] .tile-2{background:#312e81}html[data-theme=halloween] .tile-4{color:#f5f3ff;background:#6d28d9}html[data-theme=halloween] .tile-8{color:#fdf4ff;background:#a21caf}html[data-theme=halloween] .tile-16{color:#fff1f2;background:#be123c}html[data-theme=halloween] .tile-32{color:#ffedd5;background:#9a3412}html[data-theme=halloween] .tile-64{color:#fefce8;background:#a16207}html[data-theme=halloween] .tile-128{color:#f7fee7;background:#3f6212}html[data-theme=halloween] .tile-256{color:#f0fdf4;background:#166534}html[data-theme=halloween] .tile-512{color:#ecfeff;background:#155e63}html[data-theme=halloween] .tile-1024{color:#eff6ff;background:#1e3a5f}html[data-theme=halloween] .tile-2048{color:#451a03;background:#facc15;box-shadow:0 0 18px #facc1580}html[data-theme=halloween] .tile-super{color:#fef2f2;background:#450a0a}html[data-theme=christmas] .board{background:#07130c}html[data-theme=christmas] .well{background:#14301f}html[data-theme=christmas] .tile-face{color:#6b5844;background:#f3ead8}html[data-theme=christmas] .tile-2{background:#f3ead8}html[data-theme=christmas] .tile-4{background:#ecd9b0}html[data-theme=christmas] .tile-8{color:#f9f6f2;background:#1e3a5f}html[data-theme=christmas] .tile-16{color:#f9f6f2;background:#b91c1c}html[data-theme=christmas] .tile-32{color:#f9f6f2;background:#15803d}html[data-theme=christmas] .tile-64{color:#f9f6f2;background:#166534}html[data-theme=christmas] .tile-128{color:#f9f6f2;background:#ca8a04}html[data-theme=christmas] .tile-256{color:#451a03;background:#eab308}html[data-theme=christmas] .tile-512{color:#451a03;background:#f59e0b}html[data-theme=christmas] .tile-1024{color:#f9f6f2;background:#0f766e}html[data-theme=christmas] .tile-2048{color:#451a03;background:#facc15;box-shadow:0 0 18px #facc158c}html[data-theme=christmas] .tile-super{color:#f2efe3;background:#0a1f14}.overlay{z-index:5;background:#090b109e;border-radius:14px;justify-content:center;align-items:center;display:none;position:absolute;inset:0}.overlay-card{text-align:center;background:var(--panel);border:1px solid var(--panel-border);border-radius:var(--radius);box-shadow:var(--shadow);padding:1.1rem 1.4rem}.overlay-title{margin:0 0 .4rem;font-size:1.3rem;font-weight:700}.overlay-sub{color:var(--ink-soft);margin:0 0 .8rem}.overlay-btns{justify-content:center;gap:.5rem;display:flex}.overlay-card .btn{margin-top:.4rem}.hint{text-align:center;color:var(--ink-soft);font-size:.9rem}.how{background:var(--panel);border:1px solid var(--panel-border);border-radius:var(--radius);margin-top:.8rem;padding:.8rem 1rem}.how h2{margin:0 0 .35rem;font-size:1.05rem}.how p{color:var(--ink-soft);margin:0;line-height:1.5}.how-toggle{width:100%;font:inherit;color:var(--ink);cursor:pointer;text-align:left;background:0 0;border:0;justify-content:space-between;align-items:center;margin:0;padding:0;font-size:1.05rem;font-weight:700;display:flex}.how-chev{fill:none;stroke:currentColor;stroke-width:2.2px;stroke-linecap:round;stroke-linejoin:round;flex:none;width:19px;height:19px;transition:transform .18s}.how-toggle[aria-expanded=true] .how-chev{transform:rotate(180deg)}.how-body{margin-top:.35rem}.how-body[hidden]{display:none}.how-body p+p{margin-top:.5rem}