Peach Aviation Style Design System (DESIGN.md, Japanese UI)

Design policy: Express the "peach" through outlines. Rather than just leaning the colors toward pink, the asymmetric shape with rounded corners on two diagonal corners (the shape of a leaf) is made the common language of buttons, cards, and chips. Large circular planes (the peach fruit) are layered in the background to create rhythm - About Peach: As an LCC, "cheap and easy to understand" is the top priority. The booking form is placed directly below the first view, and from there down, navigation cards are lined up in an orderly fashion. Decoration is concentrated in outlines and surface colo