Spacing support for max()

[Azragh]

What problem does this address?

The problem with the new spacing specifications is that no distinction can be made between mobile devices and the desktop view. I therefore only allow "em" and "%" in my themes, but this only works to a limited extent.

Suppose I have 2 columns - one with an inner spacing of 4em, the other 5%. On the desktop, the whole thing looks nice and uniform:

On mobile devices, however, the spacing of the column with percentage is felt to be a bit too small, and the one with "em" a bit too big:

What is your proposed solution?

A solution would be to add a field in which a second value can be specified, which then results in padding: max(value1, value2);. In this way, values could be combined with each other as desired in order to better control the mobile view. Example with max(5%, 2em):