Create a vertical 2:3 premium product display background: a blue futuristic cloud city with a round illuminated sci-fi platform and simple retro speakers. Use an empty, clearly visible product placement surface and preserve generous balanced negative space. Use original variations in all small decorative shapes, positions, angles, reflections, and surface details. Polished high-end 3D render, clean full-bleed composition, refined studio lighting. No readable text, no numbers, no Chinese characters, no watermark, no brand logo, no trademark symbols, no corner marks, no fake text, no dirty edges, no black or white border, no cropped artifacts.
