I have a website with multiple resolution display options. Just one of them (390-719), which is picked up by iPhone 16 in portrait mode) does not centre the contents, and leaves a little blank space on the right which can be scrolled over to, thus pushing the left had side of the page out of view. It's not a major issue, but none of my otehr sites have the same problem, so I would really like to discover what is causing this. Any help would be appreciated.

This is the URL

https://www.burybaroque.net