header {
  background-image: url('../img/header_bg.jpg');
  background-repeat: no-repeat;
  background-attachment: scroll;
  background-position: center center;
  -webkit-background-size: cover;
  -moz-background-size: cover;
  background-size: cover;
  -o-background-size: cover;
  text-align: center;
  color: white;
}