JSFiddle - React, Tailwind, and code Playground

HTML

<div style="width:200px;">

    <div class="box green">
        <ul><li>Item</li></ul>
    </div>
    <div class="box red">
        <ul><li>Item</li><li>Item</li><li>Item</li><li>Item</li></ul>
    </div>
     <div class="box yellow">
        <ul><li>Item</li><li>Item</li></ul>
    </div>
    <div style="float:left;">
        <ul><li>Item</li><li>Item</li></ul>
    </div>

</div>

CSS

.box {float:left; display:block; width:100px;}
.green {background-color:green;}
.red {background-color:red;}
.yellow {background-color:yellow;}