A luxurious underground tropical spa carved into a living jungle cliffside, natural hot spring pools with steam rising amid giant philodendrons and hanging gardens, weathered stone walls wrapped in flowering vines, exotic poison dart frogs perched on mossy rocks, golden candlelight flickering against cascading waterfalls, rendered with Unreal Engine 5 raytracing and PBR materials, reimagined as hand-painted Studio Ghibli animation with visible brushstrokes, warm gouache color palette, cinematic composition with strong architectural perspective and atmospheric depth