JSFiddle - React, Tailwind, and code Playground

HTML

<div id="hiddendiv" style="height:'200';width:'200'">This is hidden DIV</div>

JavaScript

$('#hiddendiv').stop().animate({ opacity: 0.0 }, 500);

$('#hiddendiv').live('mouseenter', function(){
    $('#hiddendiv').stop().animate({ opacity: 1.0 }, 500);
});


$('#hiddendiv').live('mouseleave', function(){
    $('#hiddendiv').stop().animate({ opacity: 0.0 }, 500);
});