Lullaby

A one-screen gender reveal invitation set in a deep blue night, with a pastel star-and-moon nursery mobile swaying softly at its heart. A touch switches on the night-light to open it. Guests tap the pink or the blue star to make their guess, and once the answer is announced, tapping the moon floods the whole card in its colour. Directions, add to calendar, the reply and gentle music are all on the card.