/** ADD YOUR AWESOME CODES HERE **/

body {
  background: url('../images/sfondo.jpg') no-repeat center center fixed;
  -webkit-background-size: cover;
  -moz-background-size: cover;
  background-size: cover;
  -o-background-size: cover;
}
.bg-warning {
      background: url('../images/sfondo.jpg') no-repeat center center fixed;
}