JSFiddle - React, Tailwind, and code Playground

by Craig Haywood

HTML

<div class="video-background">
  <iframe src="https://www.youtube.com/embed/UoqScLK8tBw?controls=0&showinfo=0&rel=0&autoplay=1&loop=1&mute=1&version=3&playlist=UoqScLK8tBw" frameborder="0" allowfullscreen></iframe>
</div>
<div  class="mydiv">

</div>

CSS

.video-background {
  position: relative;
  overflow: hidden;
  width: 100vw;
  height: 100vh;
}

.video-background iframe {
  position: absolute;
  top: 50%;
  left: 50%;
  width: 100vw;
  height: 100vh;
  transform: translate(-50%, -50%);
}

@media (min-aspect-ratio: 16/9) {
  .video-background iframe {
    /* height = 100 * (9 / 16) = 56.25 */
    height: 56.25vw;
  }
}
@media (max-aspect-ratio: 16/9) {
  .video-background iframe {
    /* width = 100 / (9 / 16) = 177.777777 */
    width: 177.78vh;
  }
}
.mydiv{
  background-color: rgba(0,0,0,.7);
  position: absolute;
  z-index: 10 ! important;
  width: 100vw;
  height: 100vh;
  top: 0
}