设置固定的背景图

body {
font-size: 15px;
padding: 0;
margin: 0;
font-family: "微软雅黑","宋体",Arial;
width: 100%;
height: 100%;
background: url(https://api.lyiqk.cn/purelady?1559f782) no-repeat top center fixed !important;
background-size: cover;
}