Page margins not working properly

Hey there,

I left the site for a few days and when I came back to work on it again, the margins on the pages were completely gone. Margins used to look like this: https://selademo.wordpress.com/page-templates/full-width-page/

Now they look like this: https://writer.gigigriffis.com/about/

It’s been a week since I looked at the site, so I have literally no idea what I changed to make this happen. Can someone help?