BuddyPress.org

My website : http://www.rosenstiehl.net/network – it uses bp-default theme and a basic child theme.

I would like to use a fixed width for the body with a code like the following :
`body { width: 960px; }`
As a consequence I would like to force two other parameters :
1 – the BP-adminbar on the top of the screen should have my new width. Unfortunately, with this simple code it keeps having a variable width depending on the screen width.
2 – the Sidebar width remains fix watever the size of the screen. I’d like it to be a littlemore wider. I can’t find where to xhange it.
Thanks in advance