大理石ベースの上に作られたフォトリアリスティックなミニチュア都市ジオラマ

Create a photorealistic 12-K miniature city diorama on a polished white-marble base. GEOMETRY • ONE continuous **flat, horizontal spiral ramp** (nautilus-like). • Center = oldest cityscape; outer edge = newest. • No vertical stacking or helical tower; ramp height must remain level (±5 % at most). ERA TRANSITION (model chooses specific details) 1. 500 BC zone – era specific homes 2. 1000 AD zone – era specific homes and buildings 3. 1800 AD zone – era specific homes and buildings 4. 2025 AD zone – era specific homes and buildings BASE & LABEL Engrave the four dates on the marble rim in order: “500 BC → 1000 AD → 1800 AD → 2025 AD”. LIGHTING Neutral gray cyclorama; overhead **spiral** key-light that follows the flat ramp, casting radial shadows. QUALITY & HARD CONSTRAINTS Ultra-real, cinematic sharpness. NEGATIVE PROMPT: VERTICAL_HELIX • STACKED_TIERS • MISSING_LABEL • LOW_DETAIL • WRONG_RING_COUNT