Merging GPT into a PDF workflow is honestly genius, I always hit the same wall juggling between windows when I’m studying Japanese or even French. The constant bouncing totally killed my focus too, especially when all you’re doing is marking stuff and pasting explanations. Having an answer mode inside the PDF that does instant grading and feedback sounds miles better. Have you figured out how to keep the session history organized? Like maybe tagging the struggles so you see your weak points stacking up (sometimes I forget what grammar tripped me up last week, y’know). Also, really curious, for the explanation logs, are you making it so you can click on the wrong answer and pop the tailored AI feedback? That would be kind of sick for review days. What tech are you using to build this? Python, JS, or something else? And do you plan to open it up to other languages or just Japanese? I know a few tools like ChatPDF, Humata AI, and AIDetectPlus have chat-with-PDF features, but haven’t seen one tailored for language learning yet - yours sounds super promising!