Design a geometric vector art illustration for a t-shirt that celebrates the lively urban life of London. The artwork should prominently display a stylized cityscape, featuring recognizable elements such as the London Eye and Big Ben, all depicted in a bright and vibrant color palette, incorporating shades of blue, red, yellow, and green. The geometric style should create a modern and trendy aesthetic, perfect for the target audience. Ensure the background is clear and transparent, allowing for easy printing. Consider incorporating playful elements, such as abstract shapes, stylized clouds, or birds, that reflect the joy of city living, adding a sense of movement and liveliness to the composition.