body {
  background-color: white;
  color: yellow;
  font-family: Courier monospace;
  text-align: center;
    background-image:url('gifs/stairway.gif');
    background-size:100%;
    background-repeat: repeat-y;
    background-attachment: fixed;
    height:100%;
    width:100%;
}

div {
    position: absolute;
    top:0;
    bottom: 0;
    left: 0;
    right: 0;
    
    margin: auto;
}