Margin goes outside div when border is removed

Question

Derived from an actual problem with borders and margin on my site I have made this test example which I think acts a little strange:

Answer 1

Because margins are evil (and tend to collapse -> is it a bug? margins of P element go outside the containig div). In your case you can simply add overflow:hidden; to .outer

http://jsfiddle.net/yhAaQ/