is -negative margin or padding invalid CSS according to W3C?

is -negative margin or padding are inval开发者_如何学Cid CSS aaccording to W3C ?

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According to Cascading Style Sheets Level 2 Revision 1 (CSS 2.1) Specification - 8.4 Padding properties, negative margin values are valid, negative padding values are not:

Unlike margin properties, values for padding values cannot be negative