@namespace url("http://www.mozilla.org/keymaster/gatekeeper/there.is.only.xul");
/* to hide the native tabs */
#TabsToolbar {
visibility: collapse;
}
/* to hide the sidebar header */
#sidebar-header {
visibility: collapse;
}
You probably want to enable the menu bar if you do this, to stop the minimize/maximize/close buttons from overlapping the menu & other buttons on the right top corner.
