Digital illustration, playful, whimsical. A cartoon unicorn character with a rainbow mane and tail stands on a cloud, looking to the right with a friendly expression. The unicorn has a white body, a rainbow mane and tail, and a horn on its head. The background features a rainbow arching over the unicorn's head, with stars and clouds in a light purple sky. The unicorn is standing on a cloud, which is white with a soft shadow underneath. The overall composition is cheerful and fantastical, suitabl