JavaScript Can Change HTML Styles (CSS) Code:

<!DOCTYPE html>
<html>
<body>

<h2>What Can JavaScript Do?</h2>

<p id="demo">JavaScript can change the style of an HTML element.</p>

<button type="button" onclick="document.getElementById('demo').style.fontSize='35px'">Click Me!</button>

</body>
</html> 



Code Description: 

JavaScript Can Change HTML Styles (CSS)

Changing the style of an HTML element, is a variant of changing an HTML attribute:

Code OUTPUT:

What Can JavaScript Do?

JavaScript can change the style of an HTML element.