Not Centered on Mobile Phone

I’ve created this page to serve as a landing page for Instagram. Strangely, it is centered on my desktop browser, and on Safari on my iPad, but it’s off center–to the right–on my cell phone.

I’m using the Enfold theme, which is generally super compatible with cell phone displays. Has Blank Slate somehow nixing this responsive capacity?

The page I need help with: [log in to see the link]