Stackedit doesn't accept custom CSS

I'm trying to follow this guide:

AlPacini's Space: Markdown - StackEdit's HTML export template with highlighting by using Prettify or Highlight.js and personalized markDown.css

in order to improve my markdown rendering.

Now, I simply copied and pasted the default template proposed by this guy. Stackedit should now refer to the custom css shown in the blog post (via google drive), but instead, in the live preview, I cannot observe any change in the way it renders markdown. It seems to still refer to the "base.css".

Why?

Another (related) question: It would be great to customise alternative themes provided by stackedit (solarized, night, etc..). It's that possible?

Thanks.

In order to use the template, you should paste it into "Default template". Then use "export to disk -> using template"

StackEdit changed a bit since I wrote the blog post.

Stackedit was an opensource project (and it should still be); try to find its repository and then the non-minified css. You are now able to download it and to edit. The other option is to open the theme html source and to download the css.