JSFiddle - React, Tailwind, and code Playground

by stopsatgreen

HTML

<div class="container">
    <div class="bum"></div>
</div>

CSS

.container { padding: 1em; }
.bum {
    background-color: red;
    min-height: 3em;
    opacity: 0;
    transition: visibility 10ms, opacity 1s 10ms;
    visibility: hidden;
}
.container:hover .bum {
    opacity: 1;
    visibility: visible;
}