abdirahman libanPro Student 2,163 Points
about vertical margin collapse
why i have to put top margin of (h1) =0 instead i can put padding = 1em 0; for the (h1)?
Adding padding to your h1 element will not solve your vertical margin collapse issue, because padding will be added within the h1 element and therefore will not affect the margins.
See my quick screencast, that i created with Jing, that tries to explain it for you.
Hope this helps explain it for you.