nano universe Style Design System (DESIGN.md, Japanese UI)

Design policy: Fashion-minimal. An edgy, urban design based on monochrome with neon yellow-green accents - Density: A fashion EC style that packs information using a small base font (12px) while ensuring a sense of breathing room through whitespace and imagery - Keywords: Sharp, monochrome, geometric, urban, refined - Characteristics: Buttons have no rounded corners at all (radius 0px). Uses Gill Sans Nova, a geometric Latin typeface. The light gray (#f4f4f4) page background creates a softer tone than pure white