/* FLOWING BLUE — the palette. DO NOT duplicate these values anywhere else.
   Loaded by the film (with theme.css) and by the document pages (with
   pages.css), so both share exactly one definition.

   Rationale and measured contrast ratios:
   2026-08-01-site-pages-migration-design.md §4.1–4.2

   THE RULE THAT MATTERS: --fb-current is for solid button fills with a white
   label, and nothing else. It is 4.5:1 on the plate and 3.4:1 on the wall, so
   it is never text. On the plate text is --fb-deep / --fb-ink / --fb-meta. On
   the wall text is --fb-shallow / --fb-ink-dark. */
:root {
  /* grounds */
  --fb-wall:       #0A0A0C;   /* the film's ground, unchanged */
  --fb-plate:      #ECE3D2;   /* the piazza's plaster */
  --fb-plate-edge: #CFC2B0;   /* the piazza's stone */

  /* the brand's own blues, documented in brand-config.js */
  --fb-deep:    #003C7E;      /* headings + links on plate. 8.5:1 */
  --fb-current: #066AAB;      /* button fills ONLY, white label. 5.7:1 */
  --fb-shallow: #6AC5FE;      /* accents + links on the wall. 10.4:1 */

  /* text */
  --fb-ink:      #241F18;     /* body on plate. 12.8:1 */
  --fb-meta:     #6B6459;     /* datelines, captions. 4.6:1 */
  --fb-ink-dark: #F2EBDD;     /* body on the wall, unchanged */

  /* Georgia carries no CJK glyphs, so an implicit fallback lands on whatever
     serif the browser defaults to — Hiragino Mincho on macOS, Yu Mincho on
     Windows, and frequently a gothic sans on Android, which ships no mincho.
     Naming the CJK faces makes /ja/ deterministic. */
  --fb-font-display: Georgia, "Times New Roman", "Hiragino Mincho ProN",
                     "Yu Mincho", "Noto Serif JP", serif;
  --fb-font-body: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, system-ui,
                  "Hiragino Kaku Gothic ProN", "Yu Gothic", "Noto Sans JP", sans-serif;
}