JSFiddle - React, Tailwind, and code Playground

HTML

<div id="id1" class="class1"><h2>Title</h2>
<p>
News News News News News News News News News News News News News News News News News News News News News News News News News News News News News News News News News News News News News News News News News News News News News News News News News News News News News News News News News News News News News News News News News 
</p></div>
<div id="id2" class="class2"><h2>Title</h2>
<p>
News News News News News News News News News News News News News News News News News News News News News News News News News News News News News News News News News News News News News News News News News News News News News News News News News News News News News News News News News News News News News News News News News 
</p></div>


<div id="id3" class="class2"><h2>Title</h2>
<p>
News News News News News News News News News News News News News News News News News News News News News News News News News News News News News News News News News News News News News News News News News News News News News News News News News News News News News News News News News News News News News News News News News 
</p></div>


<div id="id4" class="class2"><h2>Title</h2>
<p>
News News News News News News News News News News News News News News News News News News News News News News News News News News News News News News News News News News News News News News News News News News News News News News News News News News News News News News News News News News News News News News News News News 
</p></div>


<div id="id5" class="class2"><h2>Title</h2>
<p>
News News News News News News News News News News News News News News News News News News News News News News News News News News News News News News News News News News News News News News News News News News News News News News News News News News News News News News News News News News News News News News News News News 
</p></div>


<div id="id6" class="class2"><h2>Title</h2>
<p>
News News News...

CSS

.class1 {
	background:#FF0000;
}
.class2 {
	background:#fff;
}

JavaScript

function myFunction()
{
setTimeout(function(){document.getElementById('id1').className='class2'},5000);
}
myFunction()