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

Fitting an Iframe inside containers will not match the size of the container. It adds about 20px of padding. Currently there is no easy way to fix this. You need javascript (http://css-tricks.com/snippets/jquery/fit-iframe-to-content/)

Negative margins would be an easy solution.