What style or artwork was Leonardo Da Vinci?

I have to write a paper for school, and one of the requirements is to find out the style of artwork leonardo da vinci created, as an example she said, (surrealism, impressionism, realism) so im guessing it ends in an -ism, if you could help me that would be great because i have looked all over google (haha) and i cant find it ANYWHERE! thankss :]