Twenty Thirteen Css Selectors not working

I’m using the child Theme Holi of Twenty Thirteen Only thing it does is add Color Styles everything else is the same.
I also have Easy Digital Downloads plugin and the Front page is all the Downloads available.
I have tried the standard css Selectors for Twenty Thirteen
twentythirteen, #content, #nav-below, #nav-below a:first, .post
Could someone look at my site and let me know what it should be.
http://www.webcontentdatabases.com/
Thank You

http://wordpress.org/plugins/infinite-scroll/