Create a full 3D model of a modern school campus. Include a three-floor main building with a wide entrance, glass doors, a signboard, and long windows. Add corridors, classrooms with desks, a computer lab, science lab, library, principal office, staff room, and staircases. Outside, add a playground, trees, benches, plants, bicycle parking, boundary wall, front gate, and walking paths. Keep the style clean low-poly, optimized, game-ready, with smooth geometry and no holes.