SmartBank, Inc. Style Design System (DESIGN.md, Japanese UI)

Design policy: White background, black text, black pills. The only accent color is a single gradient. UI surfaces are composed almost entirely of achromatic colors (white / #f5f5f5 / black), and saturation is carried only by the coral→sun (#ff5c4d → #ffbe18) gradient text in the hero heading and by photographs. The allocation expresses the trustworthiness of a financial service through achromatic colors, and the warmth of the product through gradients - About SmartBank: Because it is a prepaid-card app, product-specific concepts are embedded directly in the tokens. Three card colors — --color-