Create a premium supermarket promotional banner background with a smooth blue gradient transitioning from deep royal blue on the left to vibrant bright blue on the right. Include a subtle central glow, soft radial lighting, and gentle vignette around the edges. Modern retail advertising style, clean corporate design, minimalistic and professional. Smooth glossy finish, high contrast, crisp details, balanced illumination, spacious layout for product placement. No products, no text, no price tags, no circles, no logos, no branding, no decorative elements. Empty advertising background only. Ultra-high resolution, photorealistic quality, 4K, print-ready, commercial supermarket flyer design. Mehr sehen