复古教科书插画风格提示

Transform this image into a retro schoolbook illustration from the 1970s or 1980s. Use flat, slightly muted colors like ochre, faded green, and burnt orange. Apply clean black ink outlines and simulate the texture of printed paper. Characters should have slightly stiff but expressive postures, with simple facial features and school-style clothing. The scene should feel nostalgic, educational, and warm.