I cannot see any padding on the preview or when I saved.
As soon as the size is less than 980px the are no padding although the padding is set to 40px.
I’ve saved and viewed on several computers with different browsers. I tried on tablet (iPad) and iPhone.
Have a look: http://redhousepr.com/current-clients/aldeburgh-festival
By the way, will you have a look on the grey arrows icons at the top beside the header? As soon as the page is under 975px the arrows jumps over to a new row and the arrows and the header are suddenly on three rows instead of one as they were from the beginning.