TOKYU Style Design System (DESIGN.md, Japanese UI)

Design policy: Layer warm gray (portal-gray-*) gradations on a white background, and express the calm and trustworthiness of a railway/lifestyle infrastructure through teal #045f68 pill CTAs. TOKYU RED #f93628 is reserved exclusively for alerts and NEW badges, and is not used for CTAs - Density: The line-height is uniformly 1.5 across all levels. Heading letter-spacing is normal (0) with no tightening, and body text is also normal. Despite being a high-information-density railway portal, breathing room is secured through whitespace - Keywords: Warm gray, teal CTA, pill buttons, stability of a