.game-board{display:flex;flex-direction:column;align-items:center;justify-content:center;padding:20px}.game-container{border:2px solid #333;background-color:#f0f0f0}.game-board-grid{display:grid;border:1px solid #ccc}.empty-cell{background-color:#e0e0e0}.start-button{padding:12px 24px;font-size:16px;background-color:#4caf50;color:#fff;border:none;border-radius:4px;cursor:pointer;transition:background-color .3s}.start-button:hover{background-color:#45a049}