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

Design policy: Clean, trustworthy business UI. Minimal design that eliminates decoration and prioritizes content and usability. - Density: For business applications with high information density. Information is displayed compactly, though with some whitespace. - Keywords: Trustworthy, clear, efficient, accessible, neutral - Characteristics: Soft neutral colors based on warm gray (Stone family). A warm-leaning tone rather than pure gray.