html - 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 provision for a negative padding in the W3C CSS. What is the reason behind this? Is there any obstruction to the property that prevents it's use as such? Thanks for your answers.

UPDATE

As I see, for example, in case you are using a font that has something, say, a 20px of vertical spacing, and you wish to apply a dashed border to the bottom of the font, say when a hyperlink appears. In such cases you'll find the style to be way too shabby, as the dashed border will appear 20px below the specified word. if you use negative margin, it's not going to work, as margin alters the area outside borders. Negative padding might help in such situations.

Answer 1

I recently answered a different question where I discussed why the box model is the way it is.

There are specific reasons for each part of the box model. Padding is meant to extend the background beyond its contents. If you need to shrink the background of the container, you should make the parent container the correct size and give the child element some negative margins. In this case the content is not being padded, it's overflowing.