JSFiddle - React, Tailwind, and code Playground

HTML

<a href="#" id="toggleSwitch_j">jQuery Hover</a>
<div id="theBox_3">Peek-a-boo!</div>

CSS

#theBox_3{
    display: none; 
    border: 1px solid #000;
    width: 200px;
    height: 100px;
    background-color: #ddf;
}
#toggleSwitch_j, #StayOpen {
 background-color: #cacaca;            
}

JavaScript

$(document).ready(function() {
    $("#toggleSwitch_j").hover(

    function() {
        $("#theBox_3").slideDown(500);
    }, function() {
        $("#theBox_3").slideUp(500);
    });
    
    

});