I studied 5e rules pretty thoroughly and I liked them a lot in theory. Still, (1.) I'm looking for something even more compressed (2.) I really like the whole O

I studied 5e rules pretty thoroughly and I liked them a lot in theory. Still, (1.) I'm looking for something even more compressed (2.) I really like the whole OSR ethos of higher risks, less widespread/more expensive magic, accent on problem solving, rather then grinding/war-gaming, etc.