JSFiddle - React, Tailwind, and code Playground

HTML

<div id="container">
	<div id="makeThisVisible"></div>
	<div id="thisRemainsHidden"></div>
</div>

CSS

#container {
    /*position:relative;*/
    width:500px;
    height:100px;
    border:1px solid black;
    background:Gray;
    /*OVERFLOW*/
    overflow:hidden;
    }
#makeThisVisible {
    position:absolute;
    width:240px;
    height:300px;
    float:left;
    border:1px solid red;
    background:IndianRed;
    /*OVERFLOW*/
    overflow:visible;
    margin-left:8px;
    }
#thisRemainsHidden {
    width:240px;
    height:300px;
    float:left;
    border:1px solid teal;
    background:DarkCyan;
    margin-left:250px;
    }