In your Delphi installation, as said, some FMX styles are included. You can find them in the C:\Users\Public\Documents\Embarcadero\Studio\21.0\Styles folder (the actual folder may be different according to the options selected in the installation process). One file in the folder is Air.style, containing the textual representation of an FMX style named Air. This style is simple and it is platform-neutral, meaning that it does not include variations of itself to be applied to each specific target platform. It is one style definition for all platforms, delivering the same look and feel everywhere.

You may notice some differences still exist in the visuals of the application running on different platforms. Some of these differences depend on the so-called behavioral services FMX implements to keep track of the intrinsic differences across platforms, that is, the default tab position for Android is at the top of a page control while it's at the bottom for...