body{
  color: white;
  background: black;
  background-image: url('../media/idroscalo.jpg');
  background-size: cover;
  background-position: center center;
  background-attachment: fixed;
}

body:after {
  content: "";
  background-color: rgba(0, 0, 0, 0.5);
  position: fixed;
  height: 100%;
  width: 100%;
  top:0;
  z-index: -1;
}