Does anyone else find this to be quite hard to read? Just visually. Especially length of the lines and thinness of the font.
Less facetiously: I wish more pages would give me the choice rather than forcing the content into a fixed-width format unnecessarily, or if they don't mind the extra coding (especially if their design is well thought out enough to make it easy) have a fixed width setting by default with the option to turn it off (I've seen this done by giving the user the option flipping stylesheets via a control at the top of a page) like some support different font size and colour/contrast options.
Steps:
1. max-width: 40em on wrapper element
2. font-weight increase from 300 to 400
3. include @font-face rules for Open Sans 400