:root{--bg:#262421;--panel:#302e2b;--panel-2:#3a3835;--text:#e7e1d8;--text-dim:#a39b8f;--accent:#d9a24a;--accent-dark:#b07f2e;--danger:#e06060}*{box-sizing:border-box}body{background:var(--bg);color:var(--text);min-height:100vh;margin:0;font-family:-apple-system,BlinkMacSystemFont,Segoe UI,PingFang SC,Hiragino Sans GB,Microsoft YaHei,sans-serif}.page{max-width:980px;margin:0 auto;padding:20px 16px 32px}.header{text-align:center;margin-bottom:18px}.header h1{letter-spacing:1px;margin:0;font-size:26px}.subtitle{color:var(--text-dim);margin:6px 0 0;font-size:13px}.main{justify-content:center;align-items:flex-start;gap:20px;display:flex}.board-area{flex:auto;min-width:0;max-width:560px}.status{text-align:center;background:var(--panel);border-radius:8px;justify-content:center;align-items:center;min-height:42px;margin-bottom:12px;padding:10px 12px;font-size:15px;display:flex}.status.thinking{color:var(--accent)}.status.result{background:var(--accent-dark);color:#fff;font-weight:600}.board-wrap{justify-content:center;display:flex;position:relative}.sidebar{flex-direction:column;flex-shrink:0;gap:16px;width:300px;display:flex}.sidebar section{background:var(--panel);border-radius:8px;padding:14px}.sidebar h2{color:var(--text-dim);text-transform:uppercase;letter-spacing:1px;margin:0 0 10px;font-size:13px;font-weight:600}.btn{appearance:none;border:1px solid var(--panel-2);background:var(--panel-2);color:var(--text);cursor:pointer;border-radius:6px;padding:8px 12px;font-size:14px;transition:background .15s,border-color .15s}.btn:hover:not(:disabled){border-color:var(--accent)}.btn:disabled{opacity:.45;cursor:default}.btn.active,.btn.primary{background:var(--accent);border-color:var(--accent);color:#1d1b18;font-weight:600}.btn.primary:hover{background:#e8b45f}.btn.ghost{background:0 0}.level-grid{grid-template-columns:repeat(3,1fr);gap:8px;display:grid}.btn.level{justify-content:center;align-items:center;padding:10px 4px;display:flex}.side-row{gap:8px;display:flex}.side-row .btn{flex:1}.move-list{font-variant-numeric:tabular-nums;max-height:220px;font-size:14px;line-height:1.9;overflow-y:auto}.move-list .empty{color:var(--text-dim);font-size:13px}.move-row{grid-template-columns:34px 1fr 1fr;column-gap:6px;display:grid}.move-row:nth-child(odd){background:#ffffff08}.move-row .no{color:var(--text-dim)}.actions{gap:10px;display:flex}.actions .btn{flex:1;padding:11px;font-size:15px}.footer{text-align:center;color:var(--text-dim);margin-top:22px;font-size:12px}.promotion-overlay{z-index:10;background:#0000008c;justify-content:center;align-items:center;display:flex;position:absolute;inset:0}.promotion-box{background:var(--panel);text-align:center;border-radius:10px;padding:18px 22px;box-shadow:0 8px 30px #00000080}.promotion-title{color:var(--text-dim);margin-bottom:12px;font-size:14px}.promotion-row{justify-content:center;gap:10px;margin-bottom:12px;display:flex}.promotion-piece{border:1px solid var(--panel-2);background:var(--panel-2);width:62px;height:62px;color:var(--text);cursor:pointer;border-radius:8px;font-size:40px;line-height:1}.promotion-piece:hover{border-color:var(--accent);background:#d9a24a26}.lang-row{gap:8px;display:flex}.lang-row .btn{flex:1}.btn.small{padding:6px 12px;font-size:13px}.footer a{color:inherit}@media (width<=860px){.main{flex-direction:column;align-items:stretch}.board-area{width:100%;margin:0 auto}.sidebar{width:100%}.move-list{max-height:140px}}