Prompt: Subtle seamless gradient background for professional portrait photography. Smooth transition from light brown or warm gray at the top to dark brown or cool gray at the bottom. The background looks like a star map of the Milky Way from the Hubble Telescope, with a halo of nebulae in the middle. Gradients should be very subtle, with no sharp dividing lines or sudden changes, ensuring an even vertical transition of color. Materials should be fabric or non-reflective to avoid any shine or reflection. The overall lighting needs to be soft and even, without producing shadows or highlights, and maintaining the continuity and smoothness of the picture. This background is designed to highlight the foreground without distracting the viewer, giving it a warm and cozy feel.