not just beautiful, but mad beautiful.
mad refers to the fact that when you see something or someone so beautiful, it almost makes you mad that you didn't see them before or earlier.
mad is used to suggest that the
beauty is not your ordinary
beauty, but a
beauty that is simply stunning and breathtaking.
ie. "yo, stop and check out that girl, she is
mad beautiful!"
ie. "the
dance concert was unlike anything i have ever witnessed before. It was
mad beautiful; I was speechless."