html, body, canvas, #instructions {
  position: absolute;
  width: 100%;
  height: 100%;

}

body {
  /* FF3.6-15 */
  background: -webkit-linear-gradient(top, #080d28 0%, #261300 100%);
  /* Chrome10-25,Safari5.1-6 */
  background: linear-gradient(to bottom, #080d28 0%, #261300 100%);
  /* W3C, IE10+, FF16+, Chrome26+, Opera12+, Safari7+ */
}

#instructions {
  opacity: 1;
  -webkit-transition: opacity 2s;
  transition: opacity 2s;
  background-repeat: no-repeat;
  background-position: center center;
  background-size: contain;
  background-image: url(../bj.jpg) ;
  background-size:100% 100%;
}
@media (max-height: 400px) {
  #instructions {
    display: none;
  }
}
