JSFiddle - React, Tailwind, and code Playground

HTML

<body>
  <div id="left-col">
    <div>div1</div>
    <div>div1_new</div>
  </div>
  <div id="right-col">
    <div>div2</div>
    <div>div2_new</div>
  </div>
    
   <div id="main_new">
    middle text    
  </div>
</body>

CSS

body{
  margin: 0;
}
#left-col{
  border: solid 1px #000000;
  background-color: #0066CC;
  float: left;
}
#right-col{
  border: solid 1px #000000;
  background-color: #66CC00;
  float: right;
}