Did you know? That you can see source code of default.css just following
1)http://localhost/cognos84/cgi-bin/cognos.cgi
2)http://localhost/cognos84/cgi-bin/cognos.cgi/cogadmin/css/default
3) COGNOS 8.4 shows source code of default.css using notepad.exe ???
This is a function of your webserver and not related to Cognos8.4. Your webserver should be configured to handle all the different file-types in an appropiate way. Our 8.4 installation doesn't allow to see cgi files of css files.
Thanks Ingmar that helps