JSFiddle - React, Tailwind, and code Playground

HTML

<div class="videoWrapper">
  <iframe width="560" 
          height="315"   
          src="https://www.youtube.com/embed/VaonOzUTOu8?rel=0" 
          frameborder="0" 
          allow="autoplay; encrypted-media" 
          allowfullscreen>
    </iframe>
</div>

CSS

.videoWrapper {
    position: relative;
    padding-bottom: 56.25%; /* 16:9 */
    padding-top: 25px;
    height: 0;
}
.videoWrapper iframe {
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
}