Design of sleek and modern display cases for showcasing high-end smartphones in a luxury retail setting, with a focus on elegant lines, minimalist aesthetics, and clever use of lighting to highlight the devices' features, set against a crisp white or muted gray background to maximize visual appeal, with subtle branding elements such as a metallic logo or discreet typography in a clean sans-serif font, surrounded by plenty of negative space to create a sense of sophistication and exclusivity.