JSFiddle - React, Tailwind, and code Playground

HTML

<div id="bla"></div>

CSS

#bla {
    width:400px;
    height:400px;
    background-color:green;
    display:none;
}

#bla:hover{
   background-color:red
}

JavaScript

setTimeout(function() {
         document.getElementById('bla').style.display="block";
},2000)