sd-prep flashcards topic all shuffle reset progress index
drill every section
space flip   1 again   2 good   3 easy   s shuffle
the two filters combine: pick a topic to drill one system, pick a drill to run that section across every topic (all eight sets of functional requirements, all eight API designs, every deep dive). the number on a chip is what it leaves given the other filter, so a greyed chip is an empty combination.
scheduling is five Leitner boxes: again sends a card back to box 1, good moves it up one, easy moves it up two. intervals are same session, 1 day, 3 days, 7 days, 21 days. progress is stored in this browser only.