"Hanging Out with Negative Margins"

Test Number One

Test Number Two

I am a 600px wide inner div that resides within a 700px wide header div. Since I am 600px I will center myself within my parent (#header-two) by using margin:0 auto; I don't need left and right paddings since I am a seperate div within the 700px wide header. But my parent does have left and right negative margins of -50px which causes it to hang out of the 600px wide wrapper div.