JSFiddle - React, Tailwind, and code Playground

HTML

<div id="main">
    <div id="content"></div><div id="sidebar"></div>
</div>
<div id="main">
    <div id="content"></div>
    <div id="sidebar"></div>
</div>

CSS

#main { width: 970px; }

#content { display: inline-block; width: 720px; border: 0px; padding: 0px; margin: 0px; height: 200px; background: red; }
#sidebar { display: inline-block; width: 246px; border: 0px; padding: 0px; margin: 0px; height: 200px; background: blue; }