JSFiddle - React, Tailwind, and code Playground

HTML

<div class="parent">
  <div class="child"></div>
  <div class="child"></div>
</div>

CSS

.parent {
  display: flex;
  border: 5px solid red;
}

.child {
  flex-basis: 100px;
  height: 400px;
  background: yellow;
  border: 5px solid purple;
  margin-right: 10px;
}