Champ d'astéroïdes vertical en pixel art

Create a vertical retro pixel-art space shooter background, 9:16 mobile game aspect ratio, designed as a seamless-feeling scrolling level backdrop. The scene is deep outer space with a dark navy-to-black starfield and a wide empty central flight corridor for gameplay. Add two luminous blue nebula streams running vertically along the left-center and right-center edges of the corridor, with speckled cyan particles, small bright stars, and occasional star glints. Surround the corridor with an asteroid field: exactly 34 visible rocky asteroids of varying size, irregular jagged shapes, dark charcoal surfaces, and electric blue rim lighting. Count and place them as follows: 1 huge cropped asteroid in the upper left corner, 1 huge cropped asteroid on the mid-left edge, 1 large asteroid near lower-left edge, 1 large cropped asteroid at the bottom-left corner, 1 large asteroid near upper-right edge, 1 large asteroid near mid-right edge, 1 large cropped asteroid on the lower-right edge, 1 large asteroid near bottom-right, plus 26 smaller floating asteroids scattered around the left and right sides while keeping the center mostly open. Include a large blue planet cropped into the upper-right quadrant, glowing atmospheric rim, visible curved horizon, subtle surface texture, and bright cyan edge light. Visual style: crisp high-detail pixel art / 16-bit inspired game asset, dramatic blue lighting, strong contrast, no blur, no UI, no spaceships, no characters, no text, no watermark. Use {argument name="dominant color" default="electric blue and deep navy"}, {argument name="aspect ratio" default="vertical 9:16"}, {argument name="central gameplay corridor" default="wide empty vertical corridor"}, {argument name="planet position" default="upper-right quadrant"}, and {argument name="asteroid count" default="34 visible asteroids"}.