JSFiddle - React, Tailwind, and code Playground
HTML
<div id="div1" class="my-div"></div>
CSS
.my-div {
margin: 20px;
height: 20px;
width: 20px;
background-color: #ddf;
}
JavaScript
var ids = 0;
var minhaClasse = 'my-div';
window.addEventListener('click', function(e) {
var el = e.target;
if (!el.classList.contains(minhaClasse)) return;
var div = document.createElement('div');
div.classList.add(minhaClasse);
div.id = ids++;
document.body.appendChild(div);
});