JSFiddle - React, Tailwind, and code Playground

HTML

<section>
  <div>
    Hello world
  </div>
</section>

CSS

section {
  border: 2px red dotted;
}
div{
  font-size:46px;
  transition:all .5s;
}
div#hidden{
  font-size:0px;
}

JavaScript

setTimeout(() => {
	const section = document.querySelector('section')
  var newElement = document.createElement('div');
	newElement.textContent = "new content";     
    newElement.setAttribute("ID",'hidden');
  section.appendChild(newElement)
}, 1 * 1000)

setTimeout(() => {
	var element = document.getElementById('hidden');
  console.log(element);
 element.setAttribute("ID",'');

}, 3 * 1000)