Create a flat, front-view vector illustration of the Alban Gate building in a vibrant, postmodern style. Use bold, contrasting colors like bright pink, yellow, blue, and green. Show the building's symmetrical features clearly, focusing on the central arch, twin towers with grid-like windows, and the connecting bridge. Employ bright pinks and yellows for the facade details, blue for structural elements, and a solid white background for contrast. Keep the illustration flat and free from perspective, using minimal shadows only to add slight depth, while ensuring a clean, geometric look that emphasizes color blocks and architectural forms.