在DOM上使用Vanilla js样式化CSS时，是否总是内联样式？

Question

I'm messing around with vanilla JavaScript and I noticed that when styling a document with js in the DOM the styles are inline. Is there a way to style a style sheet with javascript used on the DOM or is styling with Javascript bad practice? I was thinking it might have some uses when parts of a website change with user interaction, but I'm guessing the same thing can be accomplished with css pseudo classes. To reiterate my question can you use javascript to style a stylesheet in the DOM or is it just inline and bad practice?

body.style.backgroundColor= "blue";

Answer 1

Best practice, in my opinion, is to create classes in separate CSS file and then change element classes using JS. It looks better and also it is easier to read and understand.

But if you want to, you can change stylesheet. Read this Is it possible to alter a CSS stylesheet using JavaScript? (NOT the style of an object, but the stylesheet itself)