Hey Hannah, seems to me a few to many margins declared here.
If we were trying to be anal about our css which I think we are trying to. I would say you can specify all these on one line:
margin: 20px auto 30px; 
which I think you are trying to get?
Usually the last call would override the top two, but in this case I think the margin-top and margin bottom are more specific than margin so would probably override it.
You should probably research the syntax, to get familiar.
If you use margin by itself the following arguments are
TOP RIGHT BOTTOM LEFT if four are provided
TOP LEFT&RIGHT BOTTOM if three are provided
TOP&BOTTOM LEFT&RIGHT if two are provided