JSFiddle - React, Tailwind, and code Playground
HTML
<div id="test_unstyled"></div>
<div id="test_styled" style="background-color: red;" class="something"></div>
JavaScript
var unstyled = document.getElementById('test_unstyled'),
styled = document.getElementById('test_styled');
console.log('test_unstyled is styled?', !!(unstyled.getAttribute('style') || unstyled.className));
console.log('test_styled is styled?', !!(styled.getAttribute('style') || styled.className));