JSFiddle - React, Tailwind, and code Playground

HTML

<span class="foo"></span>

CSS

.foo
{
    width: 0;
    height: 0;
    color: white;
    transition: 0.1s;
}
@media screen and (max-width: 400px) {
    .foo {
        color: gray;
    }
}

JavaScript

$(".foo").on('transitionend', function () {
console.log("hi")
});