css 剪切属性clip-path
实现效果如下：
<!DOCTYPE html>
<html><head><style>.clipped {width: 200px;height: 200px;background-color: #3498db;clip-path: polygon(0% 0%, 100% 0%, 100% 100%, 30% 100%);}</style></head><body><div class="clipped"></div></body>
</html>
效果如下：
width: 171px;height: 171px;background: linear-gradient(90deg, rgba(0, 68, 145, 0.6) 0%) !important;background-color: #3498db;clip-path: polygon(20% 0%, 100% 0%, 100% 100%, 0% 100%, 0% 20%);