Changing the font size of entries.

I am looking to change the font size of my entries. I like the look of the “Paragraph” format but it appears to small on my screen. I would like to make it larger. I’ve played around with the style sheet but I can’t find the exact change I need to make. Can someone give me the exact wording of where I can change the font size of my entries? I am using the Mystique theme.

The website is ourfoursquare.com

Thank you for your time