#home h1{
     font-size:45px;
   }
  body{
   background-image: url("放你的背景图链接"); 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:0.7;
  }
  .wall{
      position: fixed;
     top: 0;
      left: 0;
      bottom: 0;
      right: 0;
  }
 div#midground{
      background: url("https://i.postimg.cc/PP5GtGtM/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://i.postimg.cc/z3jZZD1B/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://i.postimg.cc/PP5GtGtM/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%;
     }
 }