JSFiddle - React, Tailwind, and code Playground

HTML

<div class="container clearfix">
  <div class="left_container">

  </div>
  <div class="right_container">

  </div>
</div>

CSS

.clearfix:after {
  content: "";
  display: table;
  clear: both;
}

.container {}

.left_container {
  background-color: aqua;
  float: left;
  height: 400px;
  width: 200px;
}

.right_container {
  background-color: aquamarine;
  float: left;
  height: 400px;
  width: 300px;
}