yeah the problem starts when i use those three boxes… if i remove those clearfix and use simple clear:both then the background dont expand as wrapper content , why?? besides i was wondering if there is anyone who could just suggest me about my css.
The clear: both is not for the parent to contain the children floats. The clear: both is for an element after the floats causing the parent to envelope that element as well as the floats. If you’re adverse to using clearfix (you shouldn’t be, as Paulie_D states), you could add overflow: hidden to the parent, or float the parent (there’s a couple other ways also).