Hakutsuru Sake Brewing (HAKUTSURU) Style Design System (DESIGN.md, Japanese UI)

Design policy: Black-only rules and text on a white background. The only chromatic color is gold #d5b45c, applied only to the nav's active state and English labels. There is a clear division of roles between typefaces: Mincho for headings, Gothic for body text - Density: Relaxed. Body text is 14px with 28px line feed (2.0). Section spacing is 80–120px - Keywords: gold, Mincho headings, Japanese/Western two-tier, grade-based gradients, no rounded corners