Seamless tileable stereogram background pattern, 9:16 vertical, 2K resolution. Underwater ocean theme: smooth vertical gradient from deep turquoise at the top to warm coral-pink at the bottom. Organic pattern of small colorful fish, tiny bubbles, coral fragments and seaweed swirls distributed as fine repeating noise, plus medium-sized coral and shell shapes as anchor elements. Detail ratio 70% fine micro-detail and 30% larger macro shapes. Medium contrast, medium saturation (60-75%), harmonious analogous palette (teal, aqua, coral, soft pink). NO straight lines, NO text, NO logos, NO large empty flat areas, NO pure black or pure white patches. Painterly satisfying flow, ultra sharp, high resolution, designed to repeat seamlessly on the horizontal axis for autostereogram use.
