JSFiddle - React, Tailwind, and code Playground

HTML

<div class="parent">
    <iframe class="parent__wrapper" src="https://placekitten.com/566/313" frameborder="0" scrolling="no"></iframe>
</div>

SCSS

.parent {
  position: relative;
  padding-bottom: 56.25%;
  height: 0;

  &__wrapper {
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
  }
}