Gothenburg's tallest building has always been visible. Now it listens. With one tap, you change the color of Karlatornet for ten seconds. The moment is yours. The donation goes to charity. The light is seen by everyone. A skyscraper that usually speaks in concrete and glass — suddenly speaks back. Lights by Karlatornet isn't an app. It's a handshake between a city and the building that watches over it. A way to make something monumental feel personal. Something distant feel close. Something that towers above you feel, somehow, like yours. Because a city isn't its skyline. It's the people who look up at it.