.bg {
  width: 100%;
  height: 100%;
  position: absolute;
  left: 0;
  top: 0;
  z-index: 1;
}
.header {
  z-index: 3;
}
.contact {
  position: relative;
  z-index: 2;
  background: transparent;
}
.footer {
  z-index: 3;
}