Tokyo Metro Style Design System (DESIGN.md, Japanese UI)

Design policy: A function-first information architecture that prioritizes the reliability and legibility expected of public transit infrastructure. The UI is specialized for quickly delivering service status, station search, and ticket guidance, with decorative elements eliminated as much as possible - Density: High information density. The top page packs major functions such as the service status panel, station search, line list, and notices into a compact layout - Keywords: Trust, functional, legibility, public infrastructure, universal - Characteristics: Each of the 9 lines is assigned its