How to parse page styles without unnecessary stuff?

Question

css

The essence of the task is to take a piece of html layout from the page and, in addition, the styles necessary for it, without unnecessary rubbish, while not shove everything into the 'style' attribute for each element, tell me, are there ready-made libraries of this kind? All this magic should work on js

Answer 1

https://github.com/giakki/uncss