Make the "Watched" button more visually distinct after being clicked

I’d like to suggest a small but useful design improvement. Currently, when you mark a title as Watched, the button only changes slightly - the icon and text become a bit different, but the button itself stays mostly transparent and easy to miss. It would be much clearer if, after clicking, the entire button became a solid blue color. This would make it instantly recognizable that the movie or show has already been watched, without having to look closely.