JSFiddle - React, Tailwind, and code Playground

HTML

<div id="container">
    <div id="left">left</div>
    <div id="right">right<br /><br /><br /><br />Foobar</div>
</div>

CSS

#container {
    width: 75%;
    overflow: hidden;
}
#left {
    width: 60%;
    float: left;
    max-height: 1000px;
    background-color: #C00;
    padding-bottom: 1000px;
    margin-bottom: -1000px;
}
#right {
    width: 40%;
    float: right;
    max-height: 1000px;
    background-color: #0C0;
    padding-bottom: 1000px;
    margin-bottom: -1000px;
}