Accidentally hit command hyphen and my screen/font got smaller. How can I go back?

I hit command hyphen (dash) by mistake and the screen I was working on got smaller. I did it again, not sure why I did that!, and it got even smaller. I restarted the laptop, but it didn't change anything. Interestingly, my iMessage font is really big. I need to get back to the view I had before!

As an example, this is what it looks like right now. This is supposed to fill the screen.