JSFiddle - React, Tailwind, and code Playground

HTML

<div id="outer">
    <div id="inner1"></div>
    <div id="inner2"></div>
</div>

CSS

#outer {
    width:300px;
    height:auto;;
    background:#ccc;   
    overflow:auto;
}
#inner1 {
    float:left;
    width:100px;
    height:100px;
    background:#f00;
}
#inner2 {
    float:left;
    width:100px;
    height:100px;
    background:#0f0; 
}