#home h1{
    font-size:45px;
    background:rgba(255,255,255,0.5);
    optcity:0.5
}
    body{
    background-image: url("https://images.cnblogs.com/cnblogs_com/10672661cdq/1640359/t_200201131529beijing.jpg?t=1580564085084");
    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:0.85;
}
.wall{
    position: fixed;
    top: 0;
    left: 0;
    bottom: 0;
    right: 0;
}
div#midground{
    background: url("https://www.cnblogs.com/images/cnblogs_com/luzhanshi/1484971/o_midground.png");
    z-index: -1;
    -webkit-animation: cc 200s linear infinite;
    -moz-animation: cc 200s linear infinite;
    -o-animation: cc 200s linear infinite;
    animation: cc 200s linear infinite;
}
div#foreground{
    background: url("https://images.cnblogs.com/cnblogs_com/luzhanshi/1484971/o_foreground.png");
    z-index: -2;
    -webkit-animation: cc 253s linear infinite;
    -o-animation: cc 253s linear infinite;
    -moz-animation: cc 253s linear infinite;
    animation: cc 253s linear infinite;
}
div#top{
    background: url("https://www.cnblogs.com/images/cnblogs_com/luzhanshi/1484971/o_midground.png");
    z-index: -4;
    -webkit-animation: da 200s linear infinite;
    -o-animation: da 200s linear infinite;
    animation: da 200s linear infinite;
}
@-webkit-keyframes cc {
    from{
        background-position: 0 0;
        transform: translateY(10px);
    }
    to{
        background-position: 600% 0;
    }
}
@-o-keyframes cc {
    from{
        background-position: 0 0;
        transform: translateY(10px);
    }
    to{
        background-position: 600% 0;
    }
}
@-moz-keyframes cc {
    from{
        background-position: 0 0;
        transform: translateY(10px);
    }
    to{
        background-position: 600% 0;
    }
}
@keyframes cc {
    0%{
        background-position: 0 0;
    }
    100%{
        background-position: 600% 0;
    }
}
@keyframes da {
    0%{
        background-position: 0 0;
    }
    100%{
        background-position: 0 600%;
    }
}
@-webkit-keyframes da {
    0%{
        background-position: 0 0;
    }
    100%{
        background-position: 0 600%;
    }
}
@-moz-keyframes da {
    0%{
        background-position: 0 0;
    }
    100%{
        background-position: 0 600%;
    }
}
@-ms-keyframes da {
    0%{
        background-position: 0 0;
    }
    100%{
        background-position: 0 600%;
    }
}