:root{font-family:Inter,ui-sans-serif,system-ui,-apple-system,BlinkMacSystemFont,"Segoe UI",sans-serif;color:#111827;background:#f3f4f6;--panel:#fff;--muted:#6b7280;--line:#e5e7eb;--light:#f0d9b5;--dark:#b58863;--accent:#111827;--select:#facc15;--legal:rgba(17,24,39,.34);--last:rgba(250,204,21,.45);--xq:#d8b67d;--xq-line:#6b3f20}
*{box-sizing:border-box}html,body{min-width:320px}body{margin:0;min-height:100vh;background:linear-gradient(180deg,#f9fafb,#eef2f7);color:inherit}.app-shell{max-width:1240px;margin:auto;padding:24px}.topbar{display:flex;justify-content:space-between;align-items:center;margin-bottom:18px}.top-actions{display:flex;gap:8px}.eyebrow{font-size:.72rem;letter-spacing:.18em;font-weight:800;color:var(--muted)}h1{font-size:1.65rem;margin:3px 0 0}h2{font-size:1rem;margin:0}.icon-btn,.btn,.segmented button,.text-btn,.game-card,.square{border:0;cursor:pointer;font:inherit}.icon-btn{width:42px;height:42px;border-radius:12px;background:var(--panel);box-shadow:0 2px 10px #0000000d}.hidden{display:none!important}
.game-picker{max-width:900px;margin:70px auto 0}.picker-intro{text-align:center;max-width:640px;margin:0 auto 28px}.picker-kicker{display:inline-block;font-size:.72rem;font-weight:900;letter-spacing:.16em;color:var(--muted);margin-bottom:8px}.picker-intro h2{font-size:clamp(1.6rem,4vw,2.35rem)}.picker-intro p{color:var(--muted);line-height:1.6}.game-cards{display:grid;grid-template-columns:1fr 1fr;gap:18px}.game-card{display:grid;grid-template-columns:72px 1fr auto;align-items:center;gap:18px;text-align:left;background:var(--panel);border:1px solid var(--line);border-radius:20px;padding:22px;box-shadow:0 10px 30px #1118270d;transition:transform .18s ease,box-shadow .18s ease}.game-card:hover{transform:translateY(-2px);box-shadow:0 16px 34px #11182716}.game-symbol{display:grid;place-items:center;width:72px;aspect-ratio:1;border-radius:18px;background:#f5e7d5;font-size:48px}.xq-symbol{font-family:"Noto Serif CJK SC","Microsoft YaHei","SimSun",serif;color:#b42318}.game-card-copy{display:flex;flex-direction:column;gap:5px}.game-card-copy strong{font-size:1.16rem}.game-card-copy small{color:var(--muted);line-height:1.45}.arrow{font-size:1.5rem;color:var(--muted)}
.game-layout{display:grid;grid-template-columns:minmax(0,760px) 360px;gap:24px;align-items:start}.board-panel{min-width:0}.player-row{height:38px;display:flex;align-items:center;justify-content:space-between;padding:0 4px;font-weight:700}.status-dot{width:9px;height:9px;border-radius:50%;background:#d1d5db}.status-dot.active{background:#22c55e;box-shadow:0 0 0 4px #22c55e22}
.board-wrap{position:relative;width:min(100%,720px);margin:auto;border-radius:16px;overflow:hidden;box-shadow:0 18px 50px #11182724;border:8px solid #fff}.chess-board-wrap{aspect-ratio:1 / 1}.xiangqi-board-wrap{width:min(100%,648px);aspect-ratio:9 / 10;background:var(--xq);border-color:#fff}.board{width:100%;height:100%;user-select:none;min-width:0;min-height:0}.chess-board{display:grid;grid-template-columns:repeat(8,minmax(0,1fr));grid-template-rows:repeat(8,minmax(0,1fr))}.xiangqi-board{display:grid;grid-template-columns:repeat(9,minmax(0,1fr));grid-template-rows:repeat(10,minmax(0,1fr));background:var(--xq);padding:0}
.square{position:relative;display:grid;place-items:center;padding:0;margin:0;min-width:0;min-height:0;width:100%;height:100%;overflow:hidden;line-height:1;background:transparent}.chess-board .square{aspect-ratio:1 / 1;font-size:clamp(30px,6.4vw,66px)}.chess-board .square.light{background:var(--light)}.chess-board .square.dark{background:var(--dark)}.xiangqi-board .square{aspect-ratio:auto;font-size:clamp(23px,4.4vw,45px);border-right:1px solid color-mix(in srgb,var(--xq-line) 62%,transparent);border-bottom:1px solid color-mix(in srgb,var(--xq-line) 62%,transparent)}.xiangqi-board .square:nth-child(9n){border-right:0}.xiangqi-board .square:nth-last-child(-n+9){border-bottom:0}.xiangqi-board .square::before{content:"";position:absolute;inset:9%;border-radius:50%;opacity:0;transition:opacity .1s}.xiangqi-board .square.selected::before{opacity:1;box-shadow:0 0 0 4px var(--select) inset}.square.selected{outline:5px solid var(--select);outline-offset:-5px}.xiangqi-board .square.selected{outline:0}.square.last::before{content:"";position:absolute;inset:0;background:var(--last);opacity:1;border-radius:0;box-shadow:none}.square.legal::after{content:"";position:absolute;width:22%;aspect-ratio:1;border-radius:50%;background:var(--legal);z-index:4}.square.capture::after{content:"";position:absolute;inset:8%;border:5px solid var(--legal);border-radius:50%;z-index:4}.piece{position:relative;z-index:2;filter:drop-shadow(0 2px 1px #0003)}.xq-piece{display:grid;place-items:center;width:76%;aspect-ratio:1;border-radius:50%;background:#f6e7c8;border:2px solid #6b3f20;font-family:"Noto Serif CJK SC","Microsoft YaHei","SimSun",serif;font-weight:900;box-shadow:inset 0 0 0 2px #f6e7c8,0 2px 4px #0002}.xq-piece.red{color:#b42318;border-color:#b42318}.xq-piece.black{color:#1f2937}.coord{position:absolute;font-size:10px;font-weight:800;opacity:.65;z-index:3}.coord.file{right:4px;bottom:3px}.coord.rank{left:4px;top:3px}.river-label{position:absolute;left:0;right:0;top:50%;height:10%;transform:translateY(-50%);display:flex;align-items:center;justify-content:space-around;pointer-events:none;font-family:"Noto Serif CJK SC","Microsoft YaHei","SimSun",serif;font-size:clamp(18px,3vw,30px);letter-spacing:.35em;color:#6b3f20;background:linear-gradient(90deg,transparent,#d8b67de6 12%,#d8b67de6 88%,transparent);z-index:1}.river-label span{padding-left:.35em}
.side-panel{display:flex;flex-direction:column;gap:14px}.card{background:var(--panel);border:1px solid var(--line);border-radius:16px;padding:16px;box-shadow:0 4px 14px #1118270a}.status-line,.card-head{display:flex;justify-content:space-between;align-items:center;gap:12px}.badge{background:#eef2ff;border-radius:999px;padding:5px 9px;font-size:.75rem;font-weight:800}.segmented{display:grid;grid-template-columns:1fr 1fr;background:#f3f4f6;padding:4px;border-radius:12px;margin:14px 0}.segmented button{padding:9px;border-radius:9px;background:transparent}.segmented button.active{background:#fff;box-shadow:0 1px 5px #0001;font-weight:800}.bot-controls{margin-bottom:12px}.bot-controls label{display:flex;justify-content:space-between;align-items:center;gap:12px;font-size:.9rem}.bot-controls select{max-width:170px;border:1px solid var(--line);border-radius:9px;padding:7px 10px;background:#fff}.difficulty-note{font-size:.76rem;color:var(--muted);line-height:1.45;margin-top:7px}.actions{display:grid;grid-template-columns:1fr 1fr;gap:8px}.btn{padding:10px 12px;border-radius:10px;background:#f3f4f6;font-weight:750}.btn.primary{grid-column:1/-1;background:var(--accent);color:#fff}.history-card{min-height:240px}.text-btn{background:none;color:#4f46e5;font-size:.8rem;font-weight:700}.history{max-height:300px;overflow:auto;margin-top:12px;font-variant-numeric:tabular-nums}.move-row{display:grid;grid-template-columns:32px 1fr 1fr;padding:7px 4px;border-bottom:1px solid var(--line);font-size:.9rem}.move-row .num{color:var(--muted)}.empty,.hint-card p{color:var(--muted);font-size:.88rem}.hint-card p{line-height:1.55;margin:7px 0 0}dialog{border:0;border-radius:16px;padding:0;box-shadow:0 24px 80px #0005}dialog::backdrop{background:#11182788}.promotion-box{padding:20px}.promotion-box h3{margin-top:0}.promotion-choices{display:grid;grid-template-columns:repeat(4,1fr);gap:8px}.promotion-choices button{font-size:42px;border:1px solid var(--line);background:#fff;border-radius:12px;padding:10px;cursor:pointer}
[data-theme="dark"]{color:#f9fafb;background:#111827;--panel:#1f2937;--muted:#9ca3af;--line:#374151;--accent:#f9fafb}[data-theme="dark"] body{background:linear-gradient(180deg,#111827,#0b1220)}[data-theme="dark"] .btn,[data-theme="dark"] .segmented{background:#374151}[data-theme="dark"] .segmented button.active{background:#4b5563}[data-theme="dark"] .btn.primary{color:#111827}[data-theme="dark"] .board-wrap{border-color:#1f2937}[data-theme="dark"] .bot-controls select{background:#111827;color:#f9fafb;border-color:#4b5563}[data-theme="dark"] .game-symbol{background:#374151}
@media(max-width:980px){.game-layout{grid-template-columns:1fr}.side-panel{display:grid;grid-template-columns:1fr 1fr}.hint-card{grid-column:1/-1}.board-wrap{max-width:680px}.xiangqi-board-wrap{max-width:612px}}
@media(max-width:640px){.app-shell{padding:12px}.topbar{margin-bottom:8px}.game-picker{margin-top:28px}.game-cards{grid-template-columns:1fr}.game-card{grid-template-columns:58px 1fr auto;padding:16px;gap:13px}.game-symbol{width:58px;border-radius:14px;font-size:39px}.board-wrap{border-width:4px;border-radius:10px}.chess-board .square{font-size:clamp(30px,11.8vw,54px)}.xiangqi-board .square{font-size:clamp(22px,8.5vw,38px)}.xq-piece{width:82%;border-width:1.5px}.side-panel{display:flex}.history-card{min-height:180px}.player-row{height:34px}.card{border-radius:13px;padding:14px}.actions{grid-template-columns:1fr 1fr}.coord{font-size:8px}.bot-controls label{align-items:flex-start;flex-direction:column}.bot-controls select{max-width:none;width:100%}}