body {
  margin: 0;
  padding: 0;
}

.backgroundFrame {
  top: 0;
  left: 0;
  width: 100%;
  height: 500;
  border:none;
  z-index: -1; /* Make sure the iframe is behind other content */
  background-size: cover;
}

#backgroundFrame {
  position: fixed;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  z-index: -1; /* Make sure the iframe is behind other content */
}