Caught in the Moment | Teen Surveys Couple's Intimacy

"I want a 512x800 pixel illustration for a book cover, without any text or writing. The scene shows a 19-year-old boy inside a house, standing by a window, watching a couple outside in a low yellow grass field. The couple should be a girl with brown hair and a blond boy, holding hands and facing the ocean, far from the window. The boy inside should observe them with a sense of envy, but only his back is visible, not his face. The style should be more adult, with clean lines and minimal sketching, avoiding a childish look. The contrast between the environments is important: inside the house should feel cold and lonely, using dark and cool colors like gray; outside, warm and vibrant colors should dominate, creating a sunny, bright atmosphere. Use a concept art style