Modern Concrete Stairwell Portrait

Create a photorealistic full-body fashion portrait of {argument name="subject" default="a young adult woman"} leaning casually against a large pale concrete pillar in a modern minimalist interior. She has long dark brown wavy hair and an intentionally obscured face She wears {argument name="top" default="a plain white short-sleeve T-shirt"} and is barefoot, with one leg crossed slightly in front of the other. The setting is {argument name="location" default="a contemporary concrete stairwell with polished dark floors"}, featuring a wide staircase rising on the right, angular concrete railings, geometric window latticework near the top, and soft natural daylight casting long shadows across the floor and wall. Use realistic proportions, natural skin tones, subtle fabric folds, detailed denim texture, shallow depth of field, muted gray and blue color palette, documentary editorial photography style, vertical composition, 4:5 aspect ratio. Add a semi-transparent white watermark reading {argument name="watermark text" default="Alconia"} in the bottom-left corner.