JSFiddle - React, Tailwind, and code Playground
HTML
<h1 class="title">
Make me green
</h1>
<p class="para">
Make me red
</p>
<p class="para">
Me red too
</p>
<p class="para">
Also me
</p>
JavaScript
document.querySelector('.title').style.color="green";
var paras=document.querySelectorAll('.para');
for(i=0; i<paras.length; i++){
paras[i].style.color='red';
}