Fashion Portrait on Grand Staircase

Create a high-resolution fashion editorial photograph of a slim young woman standing on an ornate indoor staircase in a grand historic mansion. She wears a loose, flowing {argument name="dress color" default="black"} halter mini dress with gathered fabric at the neckline, open sides, a short asymmetric fluttering hem, and side tie details, paired with clean {argument name="shoe style" default="white low-top sneakers"}. Her {argument name="hair color" default="dark brown"} hair is loosely tied back with wispy strands around the face, and her face is covered by a soft square blur for anonymity. She poses elegantly on gray stone steps with one leg crossed in front of the other, one hand resting on the polished curved wooden banister, photographed from a low slightly wide-angle perspective. The setting features richly carved dark wood railings with circular floral ornament panels, tall cream-colored walls, a large window on the left casting natural daylight, a warm two-bulb wall sconce on the upper right, and a sweeping staircase curve behind her. Use realistic skin tones, detailed fabric folds, glossy carved wood, natural indoor lighting, shallow editorial depth, vertical composition, and upscale lifestyle magazine styling. Add a subtle semi-transparent watermark reading {argument name="watermark text" default="Alconia"} near the lower left on the stairs.