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

Design policy: A warm neutral base leaning toward beige, with a vivid blue #0066ff pill CTA and a mint green #40f2b4 promo badge expressing the positivity and immediacy of a store-facing SaaS - Density: Body line-height is a generous 1.75. Headings are tightened with -0.03em to -0.02em tracking. Readability takes priority over information density - Keywords: Warm neutral, vivid blue, mint accent, the well-ordered letterforms of ShoraiSansStdN, the trustworthiness of a store-facing SaaS - Characteristics: - Adopts ShoraiSansStdN (Shorai Sans Standard N, Morisawa Adobe Fonts) for the Japanese ty