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

Design policy: A minimal composition of pure white background #ffffff × dark gray text #2c2c2c. With no decorative colors, it is a corporate-leaning, typography-driven design that presents textual information itself graphically - Density: A traditional Japanese corporate site structure that draws thin gray borders (#dedede) inside horizontal navigation and cards, dividing regions with ruled lines. Information density is moderate - Keywords: Pure white background, dark gray text, wide letter-spacing, palt enabled, headings at weight 700 + letter-spacing +0.1em, zero border-radius, divided by ru