BuddyPress.org

Replace the “float: left” on #userbar and #optionsbar with “float: none” change “width: 138px” to “witdh: 100%”.

On #userbar ul#bp-nav and #optionsbar ul#options-nav remove “width: 148px.

Add “float: left” on #userbar ul li and #optionsbar ul li

Note: This is without any styling and should just point you in the right direction.