Pardon my ignorance, where can I find this source code? And how can I tell Pandoc to use it?

On Thu, 17 Oct 2019 at 11:41, John MacFarlane <jgm@berkeley.edu> wrote:

Gabriel Volpe <volpegabriel-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org> writes:

> Thanks for looking into it!
>
> It might be hard-coded, I don't see any reference to `.sourceCode` here:
> https://github.com/jgm/pandoc/blob/master/data/epub.css

This is the relevant part:

$if(highlighting-css)$
  <style>
$highlighting-css$
  </style>
$endif$

Note that this comes *before* the link to the epub stylesheet,
so you should be able to override things there.