Huge problem {content div aligning left}

I’m having a major problem trying to get my #content div back to center. It’s now stuck on the left, and for the life of me I have no idea why. I’ve been trying to troubleshoot it for a few days now and cannot figure out why it’s stuck on the left. It was working fine, but now I don’t know what I did to lock it to the left. Any ideas other than the obvious? I’ve obviously checked the CSS for it, nothing wrong there. And the div is in the header.php file and it’s the same as it’s always been. I have NO clue why it’s doing this. Any help would be greatly appreciated.

Here is the link to the blog:
https://www.thinkinguncommon.com

I’d be happy to provide any necessary files as well, really need to fix this so we can launch the blog.

Thank you,
Jason