JSFiddle - React, Tailwind, and code Playground

HTML

<div class="test">
    <div class="innerDiv">1</div>
</div>

<div class="test">
    <div class="innerDiv">2</div>
</div>

<div class="test">
    <div class="innerDiv">3</div>
</div>

<div class="test">
    <div class="innerDiv">4</div>
</div>

JavaScript

$(".test").mouseenter(function() {
                                    $(this).fadeIn("slow");
            }).mouseleave(function() {               
                                    $(this).fadeOut("slow");
            });