You are tasked with designing a futuristic sustainable cityscape using AutoCAD, incorporating architectural, civil, and environmental engineering principles. The city should feature innovative skyscrapers, efficient transportation systems, and eco-friendly infrastructure. Employ parametric design, dynamic blocks, and advanced 3D modeling techniques to create a cohesive and visually stunning urban environment. Provide detailed plans, elevations, and a 3D walkthrough, highlighting the integration of sustainable elements?