黑白螺旋楼梯，把阴影当作实体

High-contrast black-and-white architectural photograph looking upward through a concrete spiral stairwell, smooth continuous handrail, a small circular skylight, alternating luminous steps and deep shadows, controlled perspective and crisp concrete grain, no people, symmetry with subtle structural rhythm. Square 1:1 standalone finished image. No text, logo, watermark, border, grid, multi-panel layout or contact sheet.

向上仰拍混凝土螺旋楼梯井的高对比黑白建筑照片，连续光滑扶手、小圆形天窗，明亮踏步与深影交替。透视受控，混凝土颗粒清楚，没有人物，对称中有结构节奏。 方形1:1独立完整成图。不要文字、标志、水印、边框、网格、多格排版或联系表。