:root{color-scheme:dark;--bg:#101722;--panel:#182230;--line:#2c3a4c;--muted:#aab7c8;--ink:#f3f1e9;--mint:#9ce5c3;--coral:#f9ad94}*{box-sizing:border-box}body{margin:0;background:radial-gradient(ellipse at 80% 0%,#253c3c70,transparent 55%),var(--bg);color:var(--ink);font-family:system-ui,-apple-system,"Noto Sans TC",sans-serif;line-height:1.6}main{max-width:900px;margin:auto;padding:56px 28px 30px;display:grid;grid-template-columns:1fr 1fr;gap:30px 50px}header{grid-column:1/-1}.eyebrow{font-size:.72rem;letter-spacing:.19em;color:var(--mint)}h1{font-size:clamp(2.5rem,6vw,4.3rem);line-height:1.12;letter-spacing:-.045em;margin:20px 0}h1 br{display:none}.dot{color:var(--coral)}.intro{color:var(--muted);margin:0;font-size:1.05rem}.lobby{align-self:start;padding:24px;border:1px solid var(--line);border-radius:18px;background:var(--panel)}.status-row{display:flex;gap:12px;align-items:flex-start}.status-row p{margin:0 0 22px;min-height:3.2em}.signal{background:var(--muted);width:8px;height:8px;flex-shrink:0;border-radius:50%;margin-top:10px}body[data-phase=playing] .signal{background:var(--mint);box-shadow:0 0 12px #9ce5c340}body[data-phase=stopped] .signal{background:var(--coral)}button,input{font:inherit}button{cursor:pointer;border:1px solid var(--line);border-radius:10px;padding:10px 16px;color:var(--ink);background:#233044;font-weight:600;transition:background .15s,transform .15s}button:hover:not(:disabled){background:#33455e}button:focus-visible,input:focus-visible,summary:focus-visible{outline:3px solid var(--coral);outline-offset:4px}button:disabled{cursor:default;opacity:.5}.primary{background:var(--mint);color:#132b22;border-color:var(--mint)}.primary:hover:not(:disabled){background:#b9f3d8}.actions{display:flex;flex-wrap:wrap;gap:10px}#share-panel{margin-top:24px}label{display:block;font-size:.85rem;margin-bottom:10px}label span{display:block;color:var(--muted);font-size:.73rem}.share-row{display:flex;gap:8px;flex-wrap:wrap}input{min-width:0;width:100%;background:var(--bg);color:var(--muted);padding:12px;border:1px solid var(--line);border-radius:8px;font-size:.8rem}.hint{color:var(--muted);font-size:.78rem;margin:12px 0 0}.game-meta{display:flex;justify-content:space-between;color:var(--muted);font-size:.8rem}#role{color:var(--mint)}h2{font-size:1.2rem;font-weight:500;margin:12px 0 22px;min-height:1.6em}.board{display:grid;grid-template-columns:repeat(3,1fr);gap:9px}.cell{aspect-ratio:1;padding:0;font-size:clamp(2rem,5vw,3.3rem);font-weight:400;border-radius:13px;background:var(--panel);opacity:1!important;line-height:1;min-width:0}.cell:not(:disabled):hover{background:#263e42;transform:translateY(-2px)}.cell[data-mark=X]{color:var(--mint)}.cell[data-mark=O]{color:var(--coral)}.cell.win{border-color:var(--mint);background:#29433e}.rematch{margin-top:18px;width:100%}footer{grid-column:1/-1;border-top:1px solid var(--line);margin-top:8px;padding-top:20px;color:var(--muted);font-size:.77rem}footer p{max-width:760px}summary{cursor:pointer;color:var(--ink);padding:5px 0}.footer-mark{display:block;margin-top:26px;font-size:.7rem;letter-spacing:.12em;color:#718297}@media(max-width:650px){main{padding:30px 20px;grid-template-columns:1fr;gap:24px}h1 br{display:block}.game{max-width:420px;width:100%;margin:auto}.lobby{padding:20px}header{margin-bottom:4px}.cell{font-size:3rem}.game h2{margin-bottom:16px}footer{margin-top:0}}@media(prefers-reduced-motion:reduce){*{transition:none!important}}