Qilin Watermelon Commercial Poster Prompt

Vertical 3:4 Qilin watermelon theme commercial poster, front-view graphic design, {argument name="background color" default="creamy yellow"} full background, with low-contrast light orange sunburst patterns and light green melon seed scatters. A whole oval Qilin watermelon, a half-cut watermelon, and two scattered melon slices are placed in the bottom right, accurately depicting dark green longitudinal stripes, thin green rind, bright red delicate pulp, a few natural black seeds, and glistening juice; the top left features a bold, rounded, and playful hand-drawn font for '{argument name="main title" default="Qilin Watermelon"}', with pulp-red fill, creamy white inner lines, and dark green outlines, where a melon seed cleverly interacts with partial strokes without affecting legibility; the subtitle '{argument name="subtitle" default="Red Pulp, Juicy, Sweet and Refreshing"}' is placed on a green wavy ribbon, with the English 'QILIN WATERMELON' as a curved small seal. The background adds melon field ridge lines, curling vines, melon flowers, small water droplets, and halftone dots, while the foreground uses enlarged leaves to frame the edges. High-saturation Q-version vector illustration, retro screen printing grain, clear flat painting layers, maintaining print bleed areas, no black background.