CSS after & before vs. JS DOM

Question

https://code.sololearn.com/WRVCWg65QPux/?ref=app

If I want to add multiple theme (probably with pulldown menu), should I use JS DOM or CSS after & before ?

I'm familiar with JS but I have never used CSS feature. I saw these feature in Mitali's some code.

Also, should I use CSS variables or toggle (this time switch) like this?

Is CSS more efficient or JS?

Answer 1

This is a very nice question and is an important factor when working with design frameworks like React.

I will look into it more but till then refer my answer and links in this discussion.
Although around css animations but I think it's relevant to this discussion.
https://www.sololearn.com/discuss/1574889/?ref=app

Answer 2

What???
CSS is better or is more easy? For me js is easy…

Answer 3

Good question. I also like to know what's better: CSS or JS DOM