body {
    margin: 0 0;
    background-color: #000;
}


#top {
    position: absolute;
    height: 50%;
    width: 100%;
    background-color: #fff;
    z-index: 1;
  }

  #middle img {
      position: fixed;
      width: 100%;
      height: auto;
      z-index: 2;
      top: 50%;
      -ms-transform: translateY(-50%);
      transform: translateY(-50%);
  }