CSS 背景图片全屏显示

<style>
   html {
       background: url(./static/login/xia.jpg) no-repeat center center fixed;
       -webkit-background-size: cover;
       -moz-background-size: cover;
       -o-background-size: cover;
       background-size: cover;
    }
</style>

参考地址：

css-tricks.com/perfect-ful…