New request (hopefully a real one this time)! 
The inline diagrams look great in light mode:
But are pretty unreadable in dark mode (my preferred setting):
Is there any possibility to make the lines and text white in dark mode (and shift the other colours to be darker to increase legibility)?
You can try to add this line above:
%%{init: {'theme':'dark'}}%% and there are more themes on Theme Configuration | Mermaid
@Tobias Would it be possible to add some “magic” behind-the-scenes in Supernotes, so that adding %%{init: {'theme':'dark'}}%% isn’t necessary, and switching back and forth between light and dark mode just works?
