index.html
<image class="bg" src="/images/bg.png"></image>index.css
.bg {
position: absolute;
top: 0;
left: 0;
bottom: 0;
right: 0;
margin: auto;
content: "";
width: 300%;
height: 300%;
z-index: -1;
filter: blur(10px);
}原文：https://www.cnblogs.com/luxiaoyao/p/9096982.html