i am trying to get very fast and increase my intuition in very basic math like highschool geometry, algebra, trig,combinatorics, etc. Post any good online resources to practice with or textbooks so that i can make sure that i didnt miss any details or learn about more obscure/difficult topics within each subject. I have already been trying to use old math olympiad tests online, but im not sure that it is very effective to achieve my goal compared to a good textbook with a decent amount of practice problems.