A / C：原創基準提示詞
A single small bean-shaped robot with a pale green rounded body, two dark oval eyes, short rounded arms and legs, and a small orange backpack. Full body, centered, facing the camera, standing on a plain light beige background. Soft studio lighting, clean 3D illustration, no text, no logos, no watermark.

B：只把 orange backpack 改成 blue backpack；其他條件保持相同。

這是待執行的練習提示詞，不是模型輸出或一致性保證。