body {

    background-image: 
    url(https://images.cnblogs.com/cnblogs_com/zhulr/1769948/o_200521021000afc6a3f40b8710341f17d2215b934c62.jpg);
    background-position: initial;
    background-size: cover;
    background-repeat: no-repeat;
    background-attachment: fixed;
    background-origin: initial;
    background-clip: initial;
    height: 100%;
    width: 100%;
}
#home{
opacity:0.8
}