Cocoa: font size in the about me-widget

Dear Elmastudio Team:
I’m using the Cocoa theme and would like to have an “About me”-section in the header widget, just like in the Cocoa demo.
But somehow my font-sizes are so much smaller than those in the demo: http://www.aepfelundraketen.de
How can I make the font sizes larger?

Thank you very much!
Have a nice day, best regards
Nicole