Just started doing a little bit of testing on the new pre-release.
Despite the "Appearance" editor font settings stating that leaving the value empty will result in a default monospace font being used, the default is now a proportional font.
The "Appearance" settings has two fields for selecting an editor font:
Editor Font Family - which works
Editor Monospace Font Family - which does not work
I realised that having two font selectors was intentional. "Editor font family" appears to refer to the default font for body text and "Editor monospace font family" appears to refer to editor text that has been marked as code. So this field does work but I feel that what they relate to is not exactly clear as it is currently explained on the settings page and only "Editor monospace font family" defaults to monospace.
Thanks. I see it now that I know what these settings fields actually relate to
Basically in my second post I was just suggesting that the text for these settings is amended before the full release so as to inform the user what they actually do. I am quite familiar with Joplin and my initial reaction to seeing the two fields was that there had been a duplication. The descriptive text did not help correct my wrong assumption, in fact the almost identical wording reinforced it!
I don't think the WYSIWYG editor can be tweaked with CSS, but I might be wrong. You probably should open a new topic and not add comments to a topic for a version which is 6 months old.