While visiting your website on an Android mobile device the upper right side seems to be slightly cut off. It may be due to the Mozilla browser that i am using on my device. Did you do a compatible test on different mobile browser? I also used Opera browser and the result was similar. This issue can be due to the menu option that you have added on that particular region, which doesn't operate or make any sense.
No, the websit is mobile compatible. The issue is with CSS and it take a few codes to get the alignment fixed. I do not think that might be the issue. OP can only help us and himself in getting it resolved.