Why does CSS not support negative padding?

Question

I have seen this many a times that the prospect of a negative padding might help the development of CSS of certain page elements become better and easier. Yet, there is no p

Answer 1

Padding by definition is a positive integer (including 0).

Negative padding would cause the border to collapse into the content (see the box-model page on w3) - this would make the content area smaller than the content, which doesn't make sense.