How Do I Increase Font Size of a Specific Gravity Form

Hi there - I have what's probably a simple question. On the website http://www.jumpwithjill.com/win we have a Gravity Form there. We'd like to increase the font size of the text that is the field title text, the field description text, and the text that goes in the text field box as well. So for example, "School Name", "Your Name", and whatever the visitor puts in the text field box respectively. We'd like to increase the font size for all the fields on this Gravity Form (entitled "Booking Form") and if possible, we'd like to restrict the font size increases ONLY to Booking Form and not our other Gravity Form(s) used on other pages on the site.

Thank you very much in advance for your help.

Kind regards,

Adrian