BuddyPress.org

I’ve read all the answers to previous questions about how to remove “last active x minutes ago” throughout the site, and the easy fix is adding something like

span.activity {
display:none !important; }

to the end of the CSS file. But I can’t figure out which one I should add it to, I’ve tried all the ones I can find. I am using the latest Buddypress, default theme, and my site is at: http://www.alltorontosparties.org/

Thanks!!