FMXLinux is a fantastic new addition to Delphi 10.3 Rio, and Air is a sharp new style available for you to use with it. Air gives your FMXLinux project a clean, professional look, and it is easy to use.
Simply use a TStyleBook to include the style, which can be found in the Styles folder.
Here are some examples of the Air style on Linux:
The Air style also works for Windows, iOS, Android, and macOS projects.