JSFiddle - React, Tailwind, and code Playground

HTML

<div tabindex="-1">123</div>
<div tabindex="-1">456</div>

CSS

div {
    background: lightblue;
}
div + div {
    background: lightcoral;
    display: none;
}
div:focus + div, div + div:focus {
    display: block;
}