夜间发光顶棚：天花板本身成为街道光源

Design an urban canopy conceived for how it performs after dark. Show a broad flat roof whose entire soffit is a luminous surface — a stretched translucent membrane backlit from within by a concealed field of warm LEDs — so at night the underside reads as one even glowing plane and there is not a single visible light fitting anywhere. Detail the brightness as gently graded, warmest and strongest over the seating areas and falling away toward the perimeter, so the light itself defines where people should gather. Show the structure supporting it as almost invisible in the darkness: slim dark columns that disappear against the night, leaving the glowing plane apparently unsupported. Detail the effect on everything below — faces lit softly from above with no harsh shadow, paving washed in warm light, the wet surfaces returning a long reflection of the plane. Show the surrounding city as darker and cooler in tone, its windows and signage bluish against the canopy's warmth. Set it over a paved plaza with benches and a few figures sitting and walking. Show full night with a deep indigo sky. Photorealistic, glowing, warm plane against cool night, low three-quarter view.