*,*:before,*:after{box-sizing:border-box;margin:0;padding:0}:root{--bg: #0f1117;--surface: #1a1d27;--border: #2a2d3a;--accent: #5b8dd9;--text: #e8eaf0;--muted: #6b7280;--win: #22c55e;--loss: #ef4444;--draw: #f59e0b}html,body,#root{height:100%;background:var(--bg);color:var(--text);font-family:Inter,system-ui,-apple-system,sans-serif;font-size:15px}button{cursor:pointer;border:none;font-family:inherit;font-size:.9rem;border-radius:8px;padding:10px 22px;transition:opacity .15s,transform .1s}button:hover{opacity:.85}button:active{transform:scale(.97)}button:disabled{opacity:.4;cursor:not-allowed;transform:none}.setup-page{display:flex;flex-direction:column;align-items:center;justify-content:center;min-height:100vh;gap:32px;padding:24px}.setup-title{font-size:2.4rem;font-weight:700;letter-spacing:-.5px}.setup-sub{color:var(--muted);margin-top:-20px;font-size:.95rem}.setup-section{display:flex;flex-direction:column;align-items:center;gap:12px;width:100%;max-width:520px}.setup-label{color:var(--muted);font-size:.8rem;text-transform:uppercase;letter-spacing:1px}.setup-row{display:flex;gap:12px;width:100%;justify-content:center}.mode-card{flex:1;display:flex;flex-direction:column;align-items:center;gap:6px;padding:20px 16px;max-width:220px;background:var(--surface);border:2px solid var(--border);border-radius:12px;color:var(--text);cursor:pointer;transition:border-color .15s,background .15s}.mode-card:hover{border-color:var(--accent)}.mode-card.active{border-color:var(--accent);background:#1c2540}.mode-card-icon{font-size:2rem}.mode-card-desc{font-size:.78rem;color:var(--muted);text-align:center;line-height:1.4}.diff-pill{padding:8px 24px;background:var(--surface);border:2px solid var(--border);border-radius:20px;color:var(--text);transition:border-color .15s,background .15s}.diff-pill:hover{border-color:var(--accent)}.diff-pill.active{border-color:var(--accent);background:#1c2540}.start-btn{margin-top:8px;padding:12px 48px;background:var(--accent);color:#fff;font-weight:600;font-size:1rem;border-radius:10px}.error-msg{color:var(--loss);font-size:.875rem}.game-page{display:flex;justify-content:center;align-items:center;min-height:100vh;padding:24px}.game-inner{display:flex;flex-direction:column;align-items:center;gap:16px}.game-status{font-size:1.05rem;font-weight:600;letter-spacing:.01em;min-height:24px}.game-status.my-turn{color:var(--text)}.game-status.thinking{color:var(--muted)}.game-status.win{color:var(--win)}.game-status.loss{color:var(--loss)}.game-status.draw{color:var(--draw)}.game-controls{display:flex;gap:12px}.game-btn{background:var(--surface);color:var(--text);border:1px solid var(--border);padding:9px 20px;border-radius:8px}