JSFiddle - React, Tailwind, and code Playground
HTML
<p>helooop</p>
<p>helooop</p>
<p>helooop</p>
<p>helooop</p>
JavaScript
var paragraphs = document.getElementsByTagName("p");
for (var i = 0; i < paragraphs.length; i++) { paragraphs[i].style.fontSize = '45px';
}