When I inspect an element in Mozilla Firefox (version 47.0.1), I need to add some css rules in Firebug. I wanted to add
Seems like it works fine for me:
enter code herehttps://jsfiddle.net/1poxy505/1
In the fiddle you can inspect element on the black div tag and see clear: both; in there.
If your trying to add clear: both; in firebug, you can just do that by typing it.