插画风生鲜海报

Design a vertical flat vector commercial poster celebrating the fresh produce or foodstuff described in the user request. Fill the background with a single warm cream or soft pastel tone and layer in low-contrast sunburst rays, scattered seed or dot motifs, and fine halftone texture for a retro screen-print feel. Arrange the hero produce in the lower portion as bold, high-saturation flat illustration: show a whole piece, a cut half, and a few loose slices with accurate rind, flesh, seeds, and juicy glisten built from clean layered shapes. In the upper area, hand-letter a large playful rounded title naming the produce, filled with a ripe color pulled from the food itself, with a creamy inner line and a darker outline, letting one small motif interact with a stroke without hurting legibility. Add a short subtitle on a wavy ribbon banner and a small curved caption beneath it. Decorate the edges with field elements such as curling vines, blossoms, ridge lines, and water droplets, and frame the corners with enlarged leaves. Keep every layer crisp and flat with visible print grain, preserve bleed margins, and avoid photorealism, black backgrounds, watermarks, and brand logos. User request: a watermelon poster titled 'Summer sweet, juicy and refreshing'