.scroll-animation {   
  animation: scrollDown 1.5s linear infinite;
}

@keyframes scrollDown {
  0% {
    opacity: 0;
    top: 0%;
  }

  20% {
    opacity: 1;
    top: 20%;
  }

  60% {
    opacity: 1;
    top: 60%;
  }

  100% {
    opacity: 0;
    top: 100%;
  }
}

iframe {
  height: 100%;
  width: 100%;
}