Create a dynamic and visually engaging promotional poster with a top-to-bottom split that contrasts Gen Z with Millennials.  Top Half (Gen Z): The upper section is vibrant and bold, using a modern palette of neon colors like electric blue, hot pink, and bright yellow. It features realistic elements such as a smartphone with social media apps (TikTok, Instagram), a pair of AirPods, and a sleek gaming console. The background includes a digital, tech-inspired cityscape with holographic advertisements and abstract geometric patterns. Add subtle references to viral memes and trends, like a trendy LED light strip and a digital art piece, blending seamlessly into the background.  Bottom Half (Millennials): The lower section has a retro-futuristic feel with colors like teal, orange, and purple, reminiscent of early 2000s aesthetics. Include lifelike objects such as a laptop with a vintage Facebook page, a set of CDs, and a classic flip phone. The backdrop features a mix of early digital culture, including MySpace, AIM chat windows, and a nostalgic mix of vintage tech gear like a bulky desktop monitor. An old-school camera and a stack of DVDs or Blu-rays add to the era's tech and entertainment vibe.  Center Transition: Where the two halves meet, the title 'Gen Z vs Millennials' is prominently displayed in a hybrid font that merges the sleek, modern style of Gen Z with the slightly retro feel of Millennial typography. The boundary between the two sections is blended with a smooth gradient that incorporates elements from both eras, creating a cohesive yet distinct visual divide. Incorporate subtle animations or digital effects where the two worlds collide, emphasizing the generational contrast while celebrating the unique aspects of each.