Act as a steampunk concept artist with 10 years of experience in Victorian-era aesthetics. Create a highly detailed digital painting of a massive [brass and copper-plated airship] soaring above a sprawling [smog-choked Victorian metropolis] at dusk. The airship should have [intricate clockwork mechanisms], billowing steam vents, and glowing amber furnace cores visible through portholes. The city below must feature cobblestone streets, gas lamps casting pools of light, and towering spires with exposed girders. Include subtle details like tiny figures on observation decks, fluttering pennants with heraldic designs, and a sky streaked with hues of burnt orange and indigo. Render the scene with a sense of grandeur and motion, emphasizing the contrast between the airship's technological marvel and the industrial grime of the city.