I have to say that including only local resources would be nice for me too, and here I mean both images and css.

On Wednesday, May 3, 2017 at 6:04:08 AM UTC-4, John MacFarlane wrote:

If you just want to embed a css file, you could try using
--include-in-header.  (In this case, you'd need to include
the <style> and </style> tags in the css file, or put them
in separate files and use --include-in-header to include
them all in the right order.)  ALternatively you could use
a custom template with

    <style>
    $mycss$
    </style>

and fill the variable with

    pandoc --template mytemplate.html -Vmycss="$(cat mystyles.css)"

Also see the manual under --self-contained:

> Elements with the attribute `data-external="1"` will be
> left alone; the documents they link to will not be
> incorporated in the document.