JSFiddle - React, Tailwind, and code Playground

HTML

<div class="wrap">
    <div class="side_left">side</div>
    <div class="side_right">side_right</div>
    <div class="content">content</div>
</div>

CSS

.wrap{overflow:hidden;}
.side_left{width:200px;float:left;    background:#999;}
.side_right{width:200px;float:right;    background:#999;}
.content{margin:0px 200px;    background:#bbb;}