body {
    color: #000;
    background-color: #e6e6e6;
    font-family: "Helvetica Neue",Helvetica,Verdana,Arial,sans-serif;
    font-size: 12px;
    min-height: 101%;
    background: url(https://images.cnblogs.com/cnblogs_com/Jean-zhou/1540498/o_%E7%94%B5%E7%BA%BF%E6%9D%86%E4%B8%8A%E7%9A%84%E5%B0%8F%E9%B8%9F.jpg);
    opacity: 0.8;
}