SOMÈS SADDLE Style Design System (DESIGN.md, Japanese UI)

Design policy: Create "ma" (negative space) through letter-spacing and line-height. As a Hokkaido harness and leather bag maker, use only deep leather green and black, and place text with generous spacing. The brand's texture comes not from color but from negative space (aki) - Density: Extremely low. Body text is 14px / line-height 2.4, headings are letter-spacing 0.18em. The amount of information per screen is intentionally reduced - Keywords: deep green, Japanese-Western two-tier layout, line-height 2.4, letter-spacing 0.18em, zero border-radius