An Art Nouveau-inspired underwater metropolis teeming with life, where skyscrapers resemble towering coral reefs and marine creatures have symbiotic technology integrated into their biology, the scene is bathed in the ethereal glow of bioluminescent jellyfish illuminating the pathways below, while inhabitants—merfolk in elegant cybernetic attire—engage in a vibrant floating marketplace, selling both digital artifacts and ancient treasures from shipwrecks, a harmonious blend of organic and mechanical, capturing the spirit of environmental consciousness and futuristic innovation in a mesmerizing tableau.