BuddyPress.org

you’d actually have to muck around with the code a bit, because it *would* just be changing #search-login-bar width to 100%, but since it’s wrapped inside the body container which has a max width of 1300px, changing the body width to 100% would expand the entire content area — something which i’m not sure you’d really want. so really, you’d have to edit the header.php file and probably move some elements around first, then do the css later.