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

Design policy: A colorful yet organized modular UI that places category-specific, highly saturated brand color panels (blue, green, pink, red, sand, yellow) as tiles on a pure white #ffffff background. Text uses a refined, Western-leaning mixed typesetting of Helvetica Now Text + Tazugane Gothic StdN - Density: Body text 17px / line-height 24px (≈1.41), headings 19px / weight 500, buttons and CTAs all defined by a saturation curve unified in the OKLCH color space. Contrast between color surfaces is strong, but because saturation is consistent, they harmonize - Keywords: Helvetica Now Text, Taz