.parallax { overflow: hidden; position: relative }

.parallax > .background-image-holder {
  /*height: 100vh;*/
  top: -45vh;
  transition: all 0s ease !important;
  transition: opacity 0.3s ease !important;
  -webkit-transform-style: preserve-3d;
}

.background-image-holder {
  position: absolute;
  width: 100%;
  height: 100%;
  top: 0;
  left: 0;
  /*background-size: cover !important;*/
  background-position: 50% 50% !important;
  z-index: 0;
  transition: 0.3s linear;
  -webkit-transition: 0.3s linear;
  -moz-transition: 0.3s linear;
  opacity: 0;
  pointer-events: none
}
.background-image-holder img {
  display: none;
}