Change font size on blog post titles?

Hi,
I’d like to change the font size of titles of the blog posts seen on the main blog page
http://www.rinaorellanaflamenco.com/blog-2/ (The Rules of Tablao, How I Choreograph for Flamenco, etc)

Since I have the page set for the small format, the title for each post is too small- smaller than the blog post text. Where or how can I change the size?

Once I click onto the post, the font size for the title is nice and large and readable.

Thank you.