body{
    background-image: url("https://images.cnblogs.com/cnblogs_com/akagreen/1574002/o_white.bmp");
    background-color: #b0c4de;
    background-position: initial;
    background-size: cover;
    background-repeat: no-repeat;
    background-attachment: fixed;
    background-origin: initial;
    background-clip: initial;
    height:100%;
    width:100%;
    }