Creating and managing StyleSheets (USS)

In the StyleSheets pane, you can add a StyleSheet to the current UI Document (UXML) by using the "+" dropdown menu to the left of the Create new selector... field:

1. Create New USS - this will open a Save File Dialog allowing you to create a new StyleSheet in your project.
2. Add Existing USS - this will open the Open File Dialog allowing you to add an existing StyleSheet to the UI Document (UXML).

You can also access these options via the right-click menu anywhere inside the StyleSheets pane tree view.

To remove a StyleSheet from the active UI Document (UXML) you can right-click on the StyleSheet and select Remove USS. This will require a full save of all unsaved changes.

There is always a single Active StyleSheet that appears bold. If you create a new USS Selector from the Create new selector... field, it will be added to the Active StyleSheet. You can change the Active StyleSheet by right-clicking on a StyleSheet and choosing Set as Active USS.

When using Sub-Document editing, the StyleSheets belonging to the parent documents will appear grayed out. They are there to provide context but are otherwise read-only.