Blog Post Layout

Hey Guys,

New user here and I'm really liking the theme so far so thanks!

OK so I'm using the blog template with no sidebars but I don't like the content width so I've use the following CSS to manke it narrower:

.single-post #content {
max-width: 800px;
}

However, this creates a big white gap on the right-hand side of the page. How can I make the white space equal down each side so the content is in a central column as opposed to the left?

Thanks

Ben