Highly detailed, game-ready and archviz-ready Art Nouveau staircase 3D model featuring rich polished wood with flowing organic handrails, intricate swirling side panels, and deep black marble treads. Clean quad topology, fully UV-unwrapped, 4K PBR textures included (BaseColor, Normal, Roughness, Metallic, AO, Height). Perfect for luxury interior renders, historical reconstructions, high-end real-time projects, VR, and cinematic scenes.