html {
  background: url(duq.jpg);
  background-repeat: no-repeat;
    -webkit-background-size: contain;
    -moz-background-size: contain;
    -o-background-size: contain;
    background-size: contain;
    background-attachment: fixed;
    height: 100%;
    overflow: hidden;
    background-position: center center;
    display: block;
    margin: 0 auto;
}