- The posted code will not work since card-mod changed a syntax long time ago. Now it needs “card_mod” keyword. See details in Docs. (of course with my due respect to the person who proposed this code).
- Probably there is no need to place the media-player card inside a stack and then use mod-card - instead a user can directly apply a card-mod to the media-player card directly.
- The proposed code is about resizing a whole card. Probably resizing / repositioning a particular UI element might be enough. Suggest OP to ask in the main card-mod thread which already has plenty of examples for media-player cards (both stock and custom).