Currently creating some Gutenberg blocks, and some of them will have a fairly standard admin interface (no need for much/any custom css).
Are there any reference materials for using the core WP Admin styles to build component interfaces? This is for the admin area only, I've had a look and the only references I've found online are quite dated (pre-Gutenberg).
The tutorial "Building a custom block editor" in the Developer Docs may be a good place to start. This tutorial takes you through building your own "block editor" and uses all the common modern UI components. You could expand on this tutorial to create your Admin UI/settings page for your plugin/global settings.
Alternatively, if you are looking to add controls specific to your blocks in the Block Editor UI, the Settings Sidebar might be of interest as well as the creating a Sidebar tutorial. This helps maintain a consistent UI experience for Users if the settings are per block.