Main subject: Center of the frame is an ∞-shaped blue halo, with silhouettes of Shanghai landmarks embedded on the left, and silhouettes of the Temple of Heaven embedded on the right, paired with flowing light trails and particle effects on both sides. Scene: Dark blue tech-style background, overall creating a tech-business atmosphere of urban interconnection and coordinated development. Style: Modern digital tech-style illustration, with glowing light effects and particle texture, a visual style commonly used for urban cooperation and dual-city linkage scenarios. Tone: Dominated by light and dark blues, with distinct color contrast to highlight a sense of technology and future. Lighting: Halo and urban silhouettes self-illuminate with glow effects, particles are dotted to enhance the画面层次感, overall lighting is even and soft. Composition: Centrally symmetric horizontal composition, with the ∞ symbol centered, light trails extending on both sides, balanced and stable frame, sufficient white space in the middle, suitable for adding text information. Usage: Suitable for dual-city linkage / urban cooperation themed PPT backgrounds, government business conference promotional materials, cross-city enterprise cooperation banners, tech summit background images, urban development promotional visuals.