JSFiddle - React, Tailwind, and code Playground

HTML

<div class="parent">
  <iframe class="child" src="https://example.com"></iframe>
</div>

CSS

.parent {
  background: red;
  width: 200px;
  height: 200px;
  overflow:auto;
}

.child {
  width:100%;
  height:100%;
  border: 0;
  
  margin: 0;
  padding: 0;
}