User Agent: Mozilla/5.0 (X11; Ubuntu; Linux x86_64; rv:33.0) Gecko/20100101 Firefox/33.0 Build ID: 20141013200257 Steps to reproduce: Added a rule with add rule option in inspector list. Actual results: Instead of showing a ".myclass:before" or ".myclass:after", it disappears. Similarly, if I add a class and change its selector to have :before, the rule disappears, though this doesn't happen to the original css rules. Expected results: It should reliably be able to change or set selector.
This is a bigger problem. Changing the selector to anything that doesn't apply to the current element will cause the new rule to disappear.