JSFiddle - React, Tailwind, and code Playground

HTML

<div class='parent'>
  <div class='child'>
    Hi
  </div>
</div>

CSS

.parent {
  background-color: #e5e5e5;
  
  /** Uncomment to bring the margins back
  margin: -1px;
  padding: 1px
  **/
}

.child {
  background-color: #999999;
  margin: 20px;
}