Vladimir said:
You can try adjusting the post width (sz_cont in CSS) and also with js file where you have the column width.
I had the same issue, and what I did was go into the snazzy-archives.js and changed the number to 7 in this line (I think it was 4?)
visible:7, // number of visible elements
and 500 in this line (I think it was 100)
def_width:500
I went to your site and noticed you still had four columns... so maybe this will help if you're trying to extend the width.