JSFiddle - React, Tailwind, and code Playground

HTML

<div id="div1">
    <li>test </li>
    <li>test 1</li>
    <li>test 2</li>
    <li>test 3</li>
</div>
<div id="div2">
    <li>test 4</li>
    <li>test 5</li>
    <li>test 6</li>
    <li>test 7</li>
</div>

CSS

#div1{
    width:256px;
    height:256px;
    border:1px black solid;
    display:block;
    float:left;
}

#div2{
    width:256px;
    display:block;
    height:256px;
    border:1px black solid;
    float:right;
}