可以实现咖啡机买卖的功能，界面很好很接近实际-用按钮实现

当鼠标接近按钮时，按钮的背景颜色发生变化；当鼠标远离时，按钮恢复原始状态。-When bringing the mouse cursor into the button its background color should be changed and when bringing the cursor out of it it should be in its original color.