A low-poly 3D rendered ancient underwater ruins cathedral at golden hour sunlight filtering through crystal clear ocean surface, massive weathered stone pillars covered in coral and barnacles support a collapsed stained-glass dome, schools of tropical fish swim through towering archways while a ghostly mermaid scholar examines ancient inscribed tablets, pixel art shell and trident icons float in UI style, warm amber sunlight rays piercing through water contrast with cool deep blue depths, volumetric light particles dancing through ocean caustics, dramatic upward perspective with deep vertical depth, nostalgic 16-bit RPG aesthetic meets modern indie art, mysterious atmosphere of forgotten oceanic civilization, color palette of deep ocean blue, warm amber sunlight, coral pink and aged stone gray, detailed pixel art scroll and pearl icons floating