JSFiddle - React, Tailwind, and code Playground

HTML

<div id ="d">
    Hello
</div>

CSS

div#d {
    width: 100px;
    height: 100px;
    background-color: red;
}

div.curs {
    cursor: pointer;
    height: 80px;
    background-color: grey;
}

JavaScript

setTimeout(function(){
    var div = document.getElementById('d');
    div.innerHTML = div.innerHTML + '<div class="curs">World</div>';    
}, 5000);