Everything just shrank – what did I do?

I was writing a post a just accidentally hit something on my keyboard (I have no idea what) and all of a sudden the font of everything on my wordpress dashboard got really small. It also made my homepage all small. Its like everything got shrunk instantly and now it looks totally messed up.

PLEASE someone tell me how to undo this stupid thing!

https://www.cultureshock.kristiejoy.net

Thanks