Different Width for Blog Page and Single Post Page

Hi

I would like to keep my container width on the blog page at 1295 px: http://i.imgur.com/dcdkaAL.png and at the same time i would like to change my single post page container width to 945 px to make it look like this: http://i.imgur.com/7oyLSm1.png

Also in the single post page i would love to center the blog post title, the date and the author. Something like this: http://i.imgur.com/cy2vlQS.png

Thanks!