Use a custom login screen when log in to the admin section.
You can also limit the admin/cms section by ip address (ranges).
The following formats are supported :
- 192.168.1.101
- 192.168.1.100-200
- 192.168.1.0/24'
- 192.168.1.*
When you are logged in, but don't have admin permissions, the normal site theme will be used.