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

Design policy: A clean, professional corporate site built on a base of white #ffffff, structured with a hierarchy of corporate navy #003349 and blue-grey #d3dee4 / #f0f4f6. A layout that takes generous whitespace and shows product photography and spatial solutions at a large scale - Density: Body text at 16px / line-height 1.8 (28.8px) for very relaxed proportions. Information is organized hierarchically, with ample whitespace secured for each section - Keywords: Noto Sans JP, corporate navy, blue-grey gradation, pill CTA (100px radius), line-height 1.8, clean / trustworthy / sincere - Charact