Why does this CSS margin-top style not work?

Question

I try to add margin values on a div inside another div. All works fine except the top value, it seems to be ignored. But why?

What I expected:
<

Answer 1

Just for a quick fix, try wrapping your child elements into a div element like this -

   

      

         Hello world!
      
   

Margin of inner div won't collapse due to the padding of 1px in-between outer and inner div. So logically you will have 1px extra space along with existing margin of inner div.