403 Forbidden in login page

Hello,
I still can't fix the problem with my https files. When I try to to access https pages, I receive this message:

You don't have permission to access //index.php on this server.
Additionally, a 403 Forbidden error was encountered while trying to use an ErrorDocument to handle the request.

My website is www.kreizy.eu

admin/config.php:
define('HTTP_SERVER', 'http://kreizy.eu');
define('HTTPS_SERVER', 'https://kreizy.eu');
define('HTTP_CATALOG_SERVER', 'http://kreizy.eu');
define('HTTPS_CATALOG_SERVER', 'https://kreizy.eu');
// Use secure webserver for catalog module and/or admin areas?
define('ENABLE_SSL_CATALOG', 'true');
define('ENABLE_SSL_ADMIN', 'false');

includes/config.php:
define('HTTP_SERVER', 'http://kreizy.eu');
define('HTTPS_SERVER', 'https://kreizy.eu');
// Use secure webserver for checkout procedure?
define('ENABLE_SSL', 'true');
// these paths are relative to top of your webspace ... (ie: under the public_html or httpdocs folder)
define('DIR_WS_CATALOG', '/');
define('DIR_WS_HTTPS_CATALOG', '/');

Thanks for your help!
Jurga