A girl wearing a blue dress and a pink headband, holding a pink balloon, standing under a vibrant rainbow. Her eyes are gently closed, and a pure, innocent smile graces her lips. The background features a series of brilliant rainbows, radiating vivid and captivating colors, creating a fantastical dream-like setting. The scene is depicted with HDR, ultra-fine painting quality, and sharp focus. The art style blends portraits and dreamy landscapes, emphasizing the girl's serene presence beneath the rainbow. The lighting should enhance the magical and sweet atmosphere of the scene, casting a soft and enchanting glow.