background: url(https://d1.lanrentuku.com/upload/img/txb/2020/08/31/5f4ca97387d20.png) no-repeat center bottom,linear-gradient(-225deg, #5D9FFF 0%, #B8DCFF 48%, #6BBBFF 100%);
css在背景图下加渐变色
原文：https://www.cnblogs.com/520yh/p/14010840.html
