:root{--primary:#6366f1;--primary-dark:#4f46e5;--primary-light:#818cf8;--accent:#ec4899;--accent-dark:#db2777;--bg:#0f172a;--bg-secondary:#1e293b;--bg-tertiary:#334155;--text:#f1f5f9;--text-secondary:#cbd5e1;--border:#475569;--shadow:#0000004d}*,:before,:after{box-sizing:border-box}body{-webkit-font-smoothing:antialiased;background:var(--bg);color:var(--text);margin:0;font-family:system-ui,-apple-system,Segoe UI,Roboto,sans-serif}.screen{flex-direction:column;justify-content:center;align-items:center;min-height:100vh;padding:2rem;display:flex}.game-container{text-align:center;width:100%;max-width:600px}.game-header{margin-bottom:2rem}.game-title{background:linear-gradient(135deg, var(--primary), var(--accent));-webkit-text-fill-color:transparent;-webkit-background-clip:text;background-clip:text;margin:0 0 1rem;font-size:2.5rem;font-weight:700}.game-status{color:var(--text-secondary);min-height:2rem;margin:.5rem 0;font-size:1.25rem;font-weight:600}.current-player{color:var(--primary-light)}.winner{color:var(--accent);font-size:1.5rem;animation:.5s ease-in-out pulse}@keyframes pulse{0%,to{transform:scale(1)}50%{transform:scale(1.05)}}.board{aspect-ratio:1;grid-template-columns:repeat(3,1fr);gap:.75rem;max-width:400px;margin:2rem auto;display:grid}.cell{background:var(--bg-secondary);border:3px solid var(--border);cursor:pointer;-webkit-user-select:none;user-select:none;border-radius:1rem;justify-content:center;align-items:center;font-size:3rem;font-weight:700;transition:all .2s;display:flex}.cell:hover:not(.filled):not(.disabled){background:var(--bg-tertiary);border-color:var(--primary);transform:scale(1.05)}.cell:active:not(.filled):not(.disabled){transform:scale(.95)}.cell.filled{cursor:default}.cell.disabled{cursor:not-allowed;opacity:.6}.cell.winner{background:var(--primary);border-color:var(--primary-light);animation:.6s ease-in-out winnerCell}@keyframes winnerCell{0%,to{transform:scale(1)}50%{transform:scale(1.1)}}.cell-x{color:var(--primary-light);animation:.3s ease-out cellAppear}.cell-o{color:var(--accent);animation:.3s ease-out cellAppear}@keyframes cellAppear{0%{opacity:0;transform:scale(0)}50%{transform:scale(1.2)}to{opacity:1;transform:scale(1)}}.controls{justify-content:center;gap:1rem;margin-top:2rem;display:flex}.btn{cursor:pointer;border:none;border-radius:.5rem;padding:.75rem 2rem;font-family:inherit;font-size:1rem;font-weight:600;transition:all .2s}.btn-primary{background:var(--primary);color:#fff}.btn-primary:hover{background:var(--primary-dark);box-shadow:0 4px 12px var(--shadow);transform:translateY(-2px)}.btn-primary:active{transform:translateY(0)}.btn-secondary{background:var(--bg-tertiary);color:var(--text);border:2px solid var(--border)}.btn-secondary:hover{background:var(--bg-secondary);border-color:var(--primary)}@media (width<=500px){.game-title{font-size:2rem}.board{gap:.5rem;max-width:320px}.cell{border-radius:.75rem;font-size:2rem}.controls{flex-direction:column;gap:.75rem}.btn{width:100%}}