JSFiddle - React, Tailwind, and code Playground

HTML

<div id="left_sidebar">
      Left
    </div>
    
    <div id="right_sidebar">
      Right
    </div>
    
    <div id="content">
      Content
    </div>

CSS

* {
  margin: 0;
  padding: 0;
}

html, body {
  height: 100%;
}

body {
  background-color: #ccc;
}

#left_sidebar, #right_sidebar {
  width: 240px;
  height: 100%;
}

#left_sidebar {
  float: left;
    background: green;
}

#right_sidebar {
  float: right;
    background: red;
}

#content {
    margin: 0 240px;
  overflow: hidden;
    height: 100%;
}