body {
    background: url("//images.cnblogs.com/cnblogs_com/xiandong/1100507/o_%e6%a1%8c%e9%9d%a2%e8%83%8c%e6%99%afIMG_7438.JPG") ;
   background-repeat:no-repeat;
    margin-top: 35px;
    padding: 0;
    font-family: 'PingFang SC','Helvetica Neue','Helvetica','Arial',sans-serif;
    margin-left: 5px;
    margin-right: 5px;
    opacity:0.7;
}