Margin Bottom not taking effect in Safari with 101% height on same element

The bottom margin or padding is not expressed in Safari with the recent changes.

I think it is because Safari will not render a margin-bottom when there is also a 101% height on the html element (which is there to prevent scroll bar jump issues on PCs).

Reverting back to using padding for the top and bottom of the body element fixes this, without changing the intended design.