.parallax {
  background-attachment: fixed;
}

.parallax .foreground {
  background-attachment: fixed;
  background-position: center;
  display: block;
  width: 100%;
  height: 100%;
  position: absolute;
  left: 0;
  top: 0;
}

@media (max-width: 800px) {
  .parallax {
    background-attachment: initial;
  }

  .parallax .foreground {
    background-attachment: initial;
  }
}