JSFiddle - React, Tailwind, and code Playground

HTML

<div id="wrapper">
      <div class="a">A</div>
      <div class="b">B</div>
      <div class="a">A</div>
      <div class="b">B</div>
    </div>

CSS

#wrapper { width: 500px;}

.a { background-color:green; float:left; width:50%;}
.b {background-color:red;float:left;width:50%;}