Forum:Remove added by tag help

I need help with removing that annoying added by tag. I checked the forums and I found a lot. They all helped me and I used the code they gave me to remove the added by tag at my wiki here: http://austinally.wikia.com/wiki/Austin_%26_Ally_Wiki But I tried to do it at my wiki here: http://disneyjessieseries.wikia.com/wiki/Jessie_Wiki and it's not working. I tried these codes:

None of them seem to work. I've been putting them in Wikia.css. Please help me. Thanks!

17:17, July 6, 2012 (UTC)
 * Even though it's possible with CSS, it's better to request its removal through Special:Contact, as that's the official method. 17:25, July 6, 2012 (UTC)

to MediaWiki:Wikia.css on your wiki. 13:39, July 8, 2012 (UTC)
 * Thank you but can someone please still help me with doing it through CSS?!
 * Jessie1010.png 23:43, July 6, 2012 (UTC)
 * Add