11. CSS Bonus ↑

11.5. Applying add-ins

And then the final option for modifying the CSS used by Notenik is to provide one or more .css files within the special add-ins folder, as described previously in our discussion of 9.4 Embedded video.

Note that any CSS “add-ins” will be applied in addition to whatever other CSS options you have chosen, through one of the means above, and not instead of any of those other options.