The login screen for the standard FarCry login, and plugins that extend it can be customised with a great looking background image. The design is responsive and resizes the image as needed. To soften the image you can opt to have an overlay that blurs, and hides image compression artefacts.
You can configure things under General Configuration:
- Background image; make it a big one
- Background position; choose the best point to pin your image
- Background mask; turn it on if you want to soften the image