Layout Builder Styles
Content editors adding a section or block to a layout have the option to apply predefined styles, such as a border or a margin. This is provided by the module Layout Builder Styles. For developers wanting to configuring new styles, see https://www.drupal.org/docs/contributed-modules/layout-builder-styles
The configuration interface is found at Administration > Configuration > Content authoring > Layout Builder Styles ()``/admin/config/content/layout_builder_style``).
The Drupal Kit defines a set of groups for organizing styles, which can be assigned to newly added styles:
Block Margins and Padding
Section Margins and Padding
Limit Items Per Row (used for some components)
General Styles (an initially empty group with no styles)