Add custom CSS properties and remove css overrides on item

Editor assessment

The subject names two coupled changes, adding custom CSS properties and removing item css overrides, and is understandable, though the card scope sitting over an item-related change slightly muddies which area was touched. No body explains why custom properties were introduced or what removing the overrides improves. Four issue references are appended, all in valid token-#value form, but they read as a chain of links without hierarchy. Hygiene is fine apart from the lowercase 'css'. A competent maintenance message whose value rests entirely on the subject; motivation is never stated.