This page helps us test the CSS Doctor. It tests 2 parts - the general UI and the set of rules.
The UI would normally be invoked from a right-click context menu on the element the user wishes to inspect.
For demo simplicity, this is mocked using this button and a left-click on the element to inspect.
Be warned - due to the tests below, there is likely to be a large and complex set of stylesheets, which could make the UI more cumbersome than it would normally be.