Use featherlight CSS

This plugin uses CSS that is different from the clean and minimal CSS provided on the Featherlight GitHub repo. For instance, it sets a font-family and font-size for the lightbox. This is very annoying, because I have to reset this values in my own CSS to match the font (size) of my site. Is it possible to return to the minimal CSS provided by the Featherlight-source? Or could this be provided as an option?

NB: I noticed that the plugin is at version 1.2.0, while the current version on GitHub is 1.7.2(!)