JSFiddle - React, Tailwind, and code Playground

HTML

<div id="container">
  <div id="left"> left</div>
  <div id="right"> right</div>
</div>

CSS

#left {
  background: #aaa;
  display: inline-block;
  width: 49%;
}

#right {
  background: cyan;
  display: inline-block;
  width: 49%;
}

#container {
  background: red;
  width: 100%
}