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

Design policy: A warm corporate design with a white base and brand orange #ed6103 used effectively for CTAs and accents. Uses the proprietary LIFULL font to create brand consistency - Density: Body text at 16px with line-height 2.0 — extremely generous line spacing. A relaxed reading experience with the ample breathing room befitting a corporate site - Keywords: orange, warm, LIFULL font, pill CTA, real estate tech, generous line spacing - Characteristics: - The proprietary LIFULL typeface is placed first in font-family. Fallbacks: Yu Gothic → Hiragino Kaku Gothic Pro W3 → Meiryo - The brand c