Also, I doubt it’s possible, but is it possible to remove the gingham design at the top of the blog?
It’s definitely possible. Try this:
.divider,
#masthead {
background: none;
}
Is there a way to use CSS to do this? [change post size]
Yep!
Try this:
#content { width: 855px; }
#main { width: 1100px; }
You can change those numbers to fit your own needs.
After you’ve done that, let me know if there’s anything else that you’d like to adjust. I’m thinking you may want to change some of your image sizes but I won’t be able to give specific help until you find a post width that suits your needs.
Cheers.