JSFiddle - React, Tailwind, and code Playground

HTML

<div class=container>
    
    <section></section>
    <aside></aside>

</div>

CSS

.container {
    background: whitesmoke;
    height: 12em;
    width: 12em;
}

.container section {
    background: slategray;
    display: inline-block;
    margin-bottom: 20px; /* change the value */
    height: 04em;
    width: 04em;
}

.container aside {
    background: gold;
    display: inline-block;
    height: 04em;
    width: 04em;
}