Path in config.php for css appears to be incorrect -
$theme_css = SM_PATH . 'config/themes/css/outlook-08.css';
On my system this caused the login.php not to use the css.
Modified to $theme_css = SM_PATH . 'themes/css/outlook-08.css'; and all appears OK, even after closing browser, clearing my cache and starting again.
This worked for both name based virtual host and URL server relative path.