The order of the margins is: top, right, bottom, left. Also, you can do a shortcut and only use two values if the top/bottom and right/left use the same values:
margin: top/bottom right/left
Just to be clear, there are no forward slashes here. This just means that the first value is for both the top and bottom margins and the second value is for both the right and left margins.
i have margin: 1em, 0; and its not working and have tried margin: 1em 0; as well as using all four margin: 1e, 0, 1e, 0; and i have not gotten anywhere.