:root{--bg:#f4f5fb;--card:#fff;--fg:#1d2033;--muted:#6b7090;--line:#dfe2ef;--x:#4f6bff;--o:#ff5a7a;--win:#2fd18b;--r:16px}
@media (prefers-color-scheme:dark){:root:not([data-theme=light]){--bg:#0f1120;--card:#191c30;--fg:#eceefa;--muted:#8a8fb0;--line:#2a2e48}}
:root[data-theme=dark]{--bg:#0f1120;--card:#191c30;--fg:#eceefa;--muted:#8a8fb0;--line:#2a2e48}
*{box-sizing:border-box}
body{margin:0;min-height:100vh;display:grid;place-items:center;background:var(--bg);color:var(--fg);font:16px/1.4 system-ui,-apple-system,Segoe UI,Roboto,sans-serif;transition:background .3s,color .3s}
.app{width:min(92vw,420px);padding:24px 0}
header{display:flex;justify-content:space-between;align-items:center}
h1{font-size:1.6rem;margin:0;letter-spacing:.02em}h1 span{color:var(--muted)}
button{font:inherit;color:inherit;cursor:pointer}
.icon-btn{background:var(--card);border:1px solid var(--line);border-radius:50%;width:40px;height:40px;font-size:1.2rem}
.controls{display:flex;gap:8px;margin:18px 0;flex-wrap:wrap}
.seg{display:flex;background:var(--card);border:1px solid var(--line);border-radius:999px;padding:3px;flex:1}
.seg button{flex:1;border:0;background:none;padding:7px 10px;border-radius:999px;color:var(--muted);transition:.2s}
.seg button[aria-checked=true]{background:var(--fg);color:var(--bg)}
.seg.disabled{opacity:.35;pointer-events:none}
.scores{display:grid;grid-template-columns:repeat(3,1fr);gap:8px}
.score{background:var(--card);border:1px solid var(--line);border-radius:12px;padding:8px;text-align:center}
.score span{display:block;font-size:.75rem;color:var(--muted)}.score b{font-size:1.4rem}
.score.x b{color:var(--x)}.score.o b{color:var(--o)}
.status{text-align:center;font-weight:600;min-height:1.4em;margin:16px 0 12px}
.board{display:grid;grid-template-columns:repeat(3,1fr);gap:10px;aspect-ratio:1}
.cell{background:var(--card);border:1px solid var(--line);border-radius:var(--r);font-size:clamp(2.5rem,14vw,4rem);font-weight:800;display:grid;place-items:center;transition:transform .15s,background .25s,box-shadow .2s}
.cell:hover:not([aria-disabled=true]){transform:translateY(-2px);box-shadow:0 6px 18px #0002}
.cell:focus-visible{outline:3px solid var(--x);outline-offset:2px}
.cell.X{color:var(--x)}.cell.O{color:var(--o)}
.cell .m{animation:pop .25s cubic-bezier(.3,1.6,.6,1)}
.cell.win{background:color-mix(in srgb,var(--win) 22%,var(--card));border-color:var(--win);animation:pulse .9s ease 2}
@keyframes pop{from{transform:scale(.3);opacity:0}}
@keyframes pulse{50%{transform:scale(1.05)}}
.actions{display:flex;gap:8px;margin-top:18px}
.btn{flex:1;padding:12px;border-radius:12px;border:0;background:var(--fg);color:var(--bg);font-weight:600;transition:transform .1s}
.btn:active{transform:scale(.97)}.btn.ghost{background:var(--card);color:var(--fg);border:1px solid var(--line)}
.hint{text-align:center;color:var(--muted);font-size:.8rem}
@media (prefers-reduced-motion:reduce){*{animation:none!important;transition:none!important}}