If you don’t know where a style comes from, UI Toolkit offers several tools to investigate styles.
You can find the styles for an element in the Matching Selectors section in the UI Builder’s Inspector.
The Matching Selectors section displays the following:
Note: USS selectors that appear lower in the list always override the same style properties in higher USS selectors.
If the Matching Selectors section doesn’t provide enough information, you can use the UI Toolkit Debugger.
The UI Toolkit Debugger window displays the following: