body {
  background-image: url("/resources/images/background.jpg");
  background-repeat: no-repeat;
  background-position: center center; /* First value is from left and second is from top. You can use use number as well*/
  -webkit-background-size: cover;
  -moz-background-size: cover;
  -o-background-size: cover;
  background-size: cover;
  width: 100%;
  height: 100%;
  position: fixed;
  left: 0;
  top: 0;
}