/* Bookfell logo (PC-223), copied verbatim from the "CSS" section of
   docs/Bookfell - Logo Addendum.md, except that .bf-logo's colour reads bf-ink
   so the plain wordmark follows the theme (PC-374). stylesheet_link_tag :app links it on every layout that calls :app. */
/* Wordmark — the logo */
.bf-logo{font-family:"Vollkorn",Georgia,serif;font-weight:600;letter-spacing:.004em;
  line-height:1;color:rgb(var(--bf-ink))}
.bf-logo.on-dark{color:#FAF7F2}

/* Icon — only where the wordmark will not fit */
.bf-mark{--s:40px;width:var(--s);height:var(--s);border-radius:calc(var(--s)*.2);
  display:grid;place-items:center;background:#6B3F09;color:#FAF7F2;line-height:1;
  font-family:"Vollkorn",Georgia,serif;font-weight:700;font-size:calc(var(--s)*.64);
  box-shadow:inset 0 calc(var(--s)*.025) 0 rgba(250,247,242,.42),
             inset 0 calc(var(--s)*-.025) 0 rgba(0,0,0,.3),
             0 1px 0 rgba(212,201,181,.9)}

/* DERIVED VALUE — do not "clean up" to 0, and do not round the font-size.
   Vollkorn's font box is asymmetric (ascent 39, descent 18 at 41px), so the
   baseline lands high and the B's ink centre sits ~3.4px above the box centre
   in a 64px tile. .082em corrects that; the remaining .015em compensates for
   the gilt edge, whose light top and dark bottom bias the perceived centre
   upward. It is a fixed fraction of the tile ONLY while font-size stays
   exactly .64 × tile — rounding font-size to whole pixels breaks the basis
   and the letter drifts by up to 4px across the size range. */
.bf-mark span{display:block;transform:translateY(.097em)}

/* Dark grounds: plain amber, no gilt. The surround already supplies the
   contrast, and the implied light source reads wrong on a real dark field. */
.bf-mark.on-dark{background:#854F0B;box-shadow:none}

/* Tagline — "Share your joy". Same family as the wordmark so the stacked
   lockup reads as one object. Sentence case, NOT title case and NOT
   letterspaced caps: it is an imperative spoken plainly, and caps put it
   back in the inscriptional register Cinzel was retired for. */
.bf-tagline{font-family:"Vollkorn",Georgia,serif;font-weight:600;
  letter-spacing:.004em;color:#6E6A61}
.bf-tagline.on-dark{color:#A26211}