Hi, I'm still a novice with CSS and can't figure out two things:

1. A couple pages on my website shifts to the right by 10px or so. I think it's somewhere in my CSS, but I can't find it. My html files are calling on a few CSS files, one that's mine (styles.css) and a few others that I got over the internet to plug in slideshow and responsive capabilities. You can see the shifts happening here:


the index2.html, visual/index.html, and print/index.html pages don't shift when I click from one to the other. But if I click from one of these pages to contact/index.html or about/index.html, the page shifts to the right.

2. When you view my website on a mobile phone, the navigation in the masthead and the footer are not centered. I can't seem to get them centered. Any suggestions?

Thanks in advance!!