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

Design philosophy: Clean, professional SaaS design. A warm stone gray #f5f5f4 background combined with brand red #f03748 CTAs and dark navy #13202f headings/footer achieves both trustworthiness and a call to action - Density: Body text uses a base line-height of 1.6, widening to 1.85 for feature descriptions. As a corporate site, it employs a spacious margin design - Keywords: Warm neutral, brand red, reliability, for small and medium businesses, dark navy footer - Characteristics: - Uses Chatwork Sans (a proprietary brand font, 4-weight configuration) for Japanese text. It is split into 4 fam