Create one finished standalone photographic website background image, 3:4 portrait, approximately 1536 by 2048 pixels. Theme: Astral atlas. Scene: An almost invisible black sphere distorts a thin field of distant white stars near the lower right, subtly bending their light. Art direction: Cinematic astronomical concept art with physically convincing star light, delicate dust and extraordinary scale. Deep black, icy silver, amber and restrained red. Avoid purple, rainbow nebula wallpaper and oversized glitter. Composition: retain generous low-detail top space suitable for overlaying website copy, adapting subject placement naturally. This is the actual background artwork, not a website mockup. No text, letters, typography, logos, borders, collages, grids or watermarks. Full-bleed, polished, richly detailed at native resolution.