How is it possible to cut the source code of a block from the Web from a page without deprivation?

Question

css

Good day. Tell me if it is possible to implement the following:
There is an object on the page (let's say a slidebar with a video), is it possible to somehow get information specifically on this object (from which files, what lines and what parameters it takes) or cut it somehow into a separate file ?
In general, is it possible to pull out the specific code for this block without unnecessary garbage?

Answer 1

HTML and CSS can be compiled by SnappySnippet for Google Chrome.

Answer 2

Plus about firebug, and if you want thrills Ctrl + U