If you’ve locked down access to your website but what your login page to pick up a stylesheet from a sub folder then you need to a add a location tag to your web.config to grant access
<location path="Styles"> <system.web> <authorization> <allow users="*" /> </authorization> </system.web> </location> <location path="Images"> <system.web> <authorization> <allow users="*" /> </authorization> </system.web> </location>
