:root{--bg-dark: #0f172a;--panel-bg: rgba(30, 41, 59, .7);--accent: #3b82f6;--gold: #fbbf24;--square-size: 44px;--glass: rgba(255, 255, 255, .05)}body{margin:0;background:var(--bg-dark);color:#f1f5f9;font-family:Inter,system-ui,sans-serif;overflow:hidden}.chess-app{height:100vh;display:flex;flex-direction:column;padding:12px;box-sizing:border-box}.app-header{display:flex;justify-content:space-between;align-items:center;padding:10px 20px;background:var(--panel-bg);-webkit-backdrop-filter:blur(10px);backdrop-filter:blur(10px);border-radius:16px;border:1px solid rgba(255,255,255,.1);margin-bottom:12px}.logo{display:flex;align-items:center;gap:12px}.logo h1{font-size:18px;margin:0;background:linear-gradient(to right,#fff,#94a3b8);-webkit-background-clip:text;-webkit-text-fill-color:transparent}.cloud-tag{font-size:9px;background:#22c55e33;color:#4ade80;padding:2px 6px;border-radius:4px;font-weight:800}.mode-selector{display:flex;background:#020617;padding:4px;border-radius:10px;gap:4px}.mode-selector button{background:transparent;border:none;color:#64748b;padding:6px 12px;border-radius:8px;cursor:pointer;font-size:12px;display:flex;align-items:center;gap:6px;transition:all .2s}.mode-selector button.active{background:var(--accent);color:#fff;box-shadow:0 4px 12px #3b82f64d}.game-container{display:grid;grid-template-columns:1fr 280px;gap:16px;flex:1;min-height:0}.board-viewport{background:radial-gradient(circle at center,#1e293b,#020617);border-radius:24px;display:flex;justify-content:center;align-items:center;perspective:1200px;position:relative;overflow:hidden;border:1px solid rgba(255,255,255,.05)}.chess-stage{transform:rotateX(35deg) rotate(-10deg);transform-style:preserve-3d;transition:transform .8s cubic-bezier(.4,0,.2,1)}.chess-stage.rotating{animation:boardRotate 20s linear infinite}@keyframes boardRotate{0%{transform:rotateX(35deg) rotate(0)}to{transform:rotateX(35deg) rotate(360deg)}}.board-grid{border:10px solid #334155;box-shadow:0 50px 100px #000c,inset 0 0 20px #00000080;background:#1e293b}.board-row{display:flex}.square{width:var(--square-size);height:var(--square-size);display:flex;justify-content:center;align-items:center;position:relative;cursor:pointer;transition:all .2s}.square.light{background:#e2e8f0}.square.dark{background:#475569}.square:hover{filter:brightness(1.2);z-index:10}.square.selected{background:#fbbf24!important;box-shadow:inset 0 0 15px #0003}.square.hint:after{content:"";width:12px;height:12px;background:#22c55e80;border-radius:50%}.coord{position:absolute;bottom:2px;right:2px;font-size:8px;color:#0003;font-weight:700}.piece-container{filter:drop-shadow(0 6px 4px rgba(0,0,0,.4));z-index:20}.piece-svg.white{color:#fff;filter:drop-shadow(0 0 1px rgba(0,0,0,.3))}.piece-svg.black{color:#0f172a}.pawn-dot{width:14px;height:14px;border-radius:50%}.pawn-dot.white{background:#fff;box-shadow:0 0 8px #fff}.pawn-dot.black{background:#1e293b;border:2px solid #475569}.ai-overlay{position:absolute;top:0;right:0;bottom:0;left:0;background:#0006;display:flex;flex-direction:column;justify-content:center;align-items:center;gap:12px;-webkit-backdrop-filter:blur(4px);backdrop-filter:blur(4px);z-index:100}.spin{animation:spin 2s linear infinite;color:var(--accent)}@keyframes spin{0%{transform:rotate(0)}to{transform:rotate(360deg)}}.side-panel{display:flex;flex-direction:column;gap:12px}.status-card{background:var(--panel-bg);padding:16px;border-radius:16px;display:flex;justify-content:space-between;align-items:center}.turn-indicator{display:flex;align-items:center;gap:10px}.dot{width:12px;height:12px;border-radius:50%}.dot.white{background:#fff;box-shadow:0 0 10px #fff}.dot.black{background:#475569;box-shadow:0 0 10px #475569}.ai-badge{font-size:10px;color:var(--gold);display:flex;align-items:center;gap:4px;animation:pulse 1.5s infinite}.history-card{flex:1;background:var(--panel-bg);border-radius:16px;padding:16px;display:flex;flex-direction:column;min-height:0}.card-header{font-size:12px;color:#94a3b8;margin-bottom:12px;display:flex;align-items:center;gap:6px}.history-list{overflow-y:auto;display:flex;flex-direction:column;gap:6px}.history-item{background:#ffffff08;padding:8px 12px;border-radius:8px;display:flex;justify-content:space-between;font-size:13px}.history-item .num{color:#475569;font-weight:700}.controls{display:grid;grid-template-columns:1fr;gap:8px}.btn-primary,.btn-secondary{border:none;padding:12px;border-radius:12px;cursor:pointer;display:flex;align-items:center;justify-content:center;gap:8px;font-size:14px;font-weight:600;transition:all .2s}.btn-primary{background:var(--accent);color:#fff}.btn-secondary{background:var(--glass);color:#94a3b8}.btn-primary:hover{transform:translateY(-2px);filter:brightness(1.1)}.loading-screen{height:100vh;display:flex;flex-direction:column;justify-content:center;align-items:center;gap:20px;background:var(--bg-dark);color:var(--accent)}.pulse{animation:pulse 2s infinite}@keyframes pulse{0%,to{opacity:1}50%{opacity:.5}}