body {
    font-size: 14px;
    font-family: 'PingFang SC', 'Microsoft YaHei', 'Helvetica Neue', 'Helvetica', 'Arial', sans-serif;
    margin-left: 20px;
    margin-right: 20px;
    margin-top: 0;
    margin-bottom: 10px;
    padding: 30px;
    padding-bottom: 10px;
    padding-top: 0;
    background-color: #d9d6cb;
    background:url(https://images.cnblogs.com/cnblogs_com/blogs/825813/galleries/2407171/o_240701060154_1bda8a51a1434fe524e9f50b255bd4969bfeb991.jpg) fixed;
}