JSFiddle - React, Tailwind, and code Playground

HTML

<div id="left">Левое меню  
</div>
<div id="content"> Content
</div><div id="right">Правое меню 
</div>

CSS

#left {
 -webkit-box-sizing: border-box;
 -moz-box-sizing: border-box;
 box-sizing: border-box;
 float: left;
    
    #right {
 -webkit-box-sizing: border-box;
 -moz-box-sizing: border-box;
 box-sizing: border-box;
 float: left; }
    
   #content {
 -webkit-box-sizing: border-box;
 -moz-box-sizing: border-box;
 box-sizing: border-box;
 float: left;
   }