[Twenty Twelve] How to remove margins(?) at sides

I forgot the link for the site:
https://czarnebaranke.pl/

Do not edit the Twenty Twelve theme. It is the default WordPress theme and having access to an unedited version of the theme is vital when dealing with a range of site issues. First create a child theme for your changes. Or install a custom CSS plugin.

Okay, done, I’ve created child theme. Next step?

body .site {
	padding: 0;
	margin-top: 0;
	margin-bottom: 0;
	box-shadow: none;
}

Try using Firefox with the Firebug add-on (or whatever developer tool is available in your web browser) to identify which CSS rules in the parent you need to over-ride in the child’s stylesheet.

Thanks a lot, guys!

One more thing though – I would like to remove duplicated site name (for example – at “Co Baranke jest?”), but still have post titles just like at the main site (ex. “Hello world”).
How to do that?

Best regards,
CB.
https://czarnebaranke.pl/

https://www.ads-software.com/search/remove+page+title+Twenty+Twelve?forums=1

Alchynyth. Thanks for the custom css as it worked like a charm. What would I have to do to create padding or margin in the header content text area and footer? I thought I had it but I must be missing a part. Thanks for any thoughts on this.

This was very helpful. Once I used the code, `body .site {
padding: 0;
margin-top: 0;
margin-bottom: 0;
box-shadow: none;
}`

The context on my site was too jammed/close to the background color. I either need to add margin or padding to my context or stretch my Header (versus removing the margin from the whole page)

Any ideas?