Change Menu Font Size

I would like to make the main menu on my website (www.chasingedenphoto.com) a larger font, but I am not sure where to find this specific menu in the CSS editor to increase the size.

I am using the “Elegant Photography Theme.” Most of the pages on my website are private at this point in time, but you can see the Home Page with the menu at the top.

Thank you in advance for your help!