apostrophe (wp-con) theme image caption sizes

I am having a hard time finding where to change the size of the image captions in the Apostrophe theme. (My site, http://www.friscovista.com/news/, is self-hosted.) The theme distinguishes between ordinary and featured posts. The featured posts have larger captions on the home page of the blog — too large for my taste. I’ve been through the css several times, but evidently I’m missing something. BTW, I am running a child theme.