Thin white border on iPhone

I have a problem with a thin white border showing at the bottom of my site right after the footer on iPhone only.

I am using an iPhone 5 with iOS8 and I also tested 4S with iOS7 and had the same problem. I have tested various Android devices and they are all fine.

I cannot find anything in my CSS that will cause this issue. I tried the negative margin method but it didn't work. If anyone else has encountered this problem, I could actually use some idea of ​​what might be causing this. Thanks in advance for your help!

Here's the link

It might be difficult to see against a white background, but here's a screenshot.