adjust width of twenty twelve blog page only

the posts page has validation errors:
https://validator.w3.org/check?uri=http%3A%2F%2Fdentaldesignofarcadia.com%2Fwpdev%2Flatest-news%2F&charset=%28detect+automatically%29&doctype=Inline&group=0

similar problems with the single post(s).

https://codex.www.ads-software.com/Validating_a_Website

also, there is a ‘max-width: 100%;’ in your child style:

body .site {
background: none; max-width: 100%!important;
margin-top: 0;
}

Most of those errors look like the theme itself. I am not sure how I could fix them.

I want the site to span the entire width of the browser, which I managed to do.

I still don’t know what the id or class element is that I need to target to get the blog page to stay within the 1000px boundary like the site content does.

Let me clarify. If you view the other pages, you will see the content appear correctly within the 1000px for the site content. The blog page is the only one not behaving.

Page with correct width.

Blog page misbehaving.

Thoughts?

You can use Firebug in FF and developer tools in IE or Chrome to identify what css is causing the problem. Great tools to learn and use!

Okay. So is there or is there not a specific tag or style for just the blog page?

Do you know what it is?

Not trying to be difficult here, but I’d really like to know.

Twenty Twelve uses body_class() which, on the posts page, outputs .blog as one of the css classes within the body tag;

https://codex.www.ads-software.com/Function_Reference/body_class

you would be able to figure that out by using a browser inspection tool as already suggested by @kmessinger

Okay, thanks for sharing that. Using the .blog class wonked the page when I tried to contain the width. I see you guys like us to do the homework.

Just have spent a lot of time already looking at source code and don’t have a lot left to spare, so I thought perhaps an expert could speed things up. Sometimes customizing WordPress can be a major puzzle, but I’ll figure it out.

All I want is the header, footer, and background image to span the page with content centered, like it is on the other pages.