Highlight saved, rendered HTML document

[Julius Hamilton]

Hello,

I would like to be able to highlight webpages offline, for better reading
comprehension of them.

I would like to save the webpage onto my computer - a feature offered by
Chrome, for example - then annotate it; just like what highlighting browser
extensions like Liner permit you to do for URLs loaded over the internet.

I recently discovered that for some reason, these tools do not work for
downloaded pages being viewed in a browser. Maybe it's because they try to
save the highlights in relation to each URL, and the downloaded pages don't
have URLs.

I was wondering if anybody could recommend a way to highlight rendered HTML
pages in Emacs. I know Emacs provides annotation tools for PDFs in
pdf-tools mode, and highlighting plaintext in a certain highlighting mode.
It seems likely that it should be possible for HTML pages too.

Just to be clear, I don't mean syntax highlighting HTML code, but rather
moving a cursor through a web document to highlight information of interest.

Would there be a good Emacs tool for this?

Thanks very much,
Julius