复古插画扁平设计SREF

This SREF style blends elements of vintage illustration and flat design. It draws heavily from mid-20th century commercial illustration traditions, particularly the advertising poster and children's book illustration styles of the 1950s-70s, while incorporating modern flat design principles of simplicity. It belongs to the vintage illustration category because it employs characteristic retro color palettes, simplified character forms, and clean contour lines that create a nostalgic yet approachable visual experience.