JSFiddle - React, Tailwind, and code Playground

HTML

<div id="container">
    
    <div id="first">
        I am the first.
    </div>

    <div id="second">
        I am the second.
    </div>
    
</div>

CSS

div#container {
    display: table;
}
div#container > div {
    display: table-cell;
    padding: 20px;
    width: 200px;
}

div#first {
    background-color: silver;
}

div#second {
    background-color: grey;
    color: white;
}

@media (max-width: 767px) {
    div#container > div#second {
        display: table-caption;
    }
}