GPT-4o的扁平图形极简风格

New style for GPT-4o: Flat Graphic Minimalism. This style is defined by: solid, flat colors without gradients or textures; minimalist approach removing non-essential details; simplification of forms into basic geometric shapes; limited, harmonious color palettes; strong, easily recognizable silhouettes; no depth or perspective, flat 2D composition; inspired by poster art and graphic design; emphasis on clarity, balance, and visual impact.