metropolis-themed  A quantum donut is a delightful fusion of physics and dessert, where the familiar ring shape of a donut is infused with the surreal properties of quantum mechanics, Its doughy center pulsates in multiple states at once, while its glazed exterior displays a mesmerizing dance of superposition,  An upside-down house is an architectural curiosity that defies gravity, where every room is built below its corresponding floor, Rooms are entered through trap doors hidden in ceilings, and furniture hovers above the occupants, creating a whimsical living experience that challenges our perception of normality, . urban, cityscape, skyscrapers, modern, futuristic, highly detailed