What comes after propositional logic?

I have always been fascinated by propositional logic. I have learnt it in school and further explored it during my engineering degree.

Recently, I used Brilliant and they gave an amazing curriculum on (propositional) logic, very engaging!

Since I have done all the challenges in brilliant, I’ve searched for books and content with more challenges.

However, I can only find literature that reiterates the theory, while I’m really interested in more complex challenges and problems. For instance: the way Brilliant teaches how to identify who is the liar when two people are asked if they are liars is awesome!

Any tips? Should I be looking for more specific literature? Should I be just be doing mock exams of tests that have logic in them (IQ tests, SATs, etc.)?