[bremensaki]

No, it's incredibly difficult to style Mastodon beyond minor CSS additions via the admin panel. If you really want to change anything substantial you need to fork the entire project.

[Timja]

I was not so much talking about the admin panel.

My question is rather if the codebase has a template directory, where one could change the templates.

And if the template format will stay stable, so that custom templates won't break in the future.