fix style: repair .space divs margin

I had set "margin:0.6em" what lead to arkward behaviour between para-
graphs. It ignored one of top or bottom margin. As it is best practice
to define margins in one direction not in both I changed it to "margin-
bottom:1.2em". See that I doubled the value.

Signed-off-by: Conrad Zelck <git@simpel.cc>