republik-style redesign: dark masthead, hero block, palette, pills

- Dark full-bleed masthead with serif wordmark and stacked nav
- Hero entry treatment: full-bleed image bg with gradient overlay
- Per-section color system (data-section) + per-post override (data-color)
- Japanese accent palette (ajisai, sakura, suna, ichigo, yuyake, sora,
  kusa, kori, amagumo, yuki) — set via `color:` in front matter
- Tag pills replace hashtag-style tags; rendered as sibling of card link
  to avoid invalid nested <a> elements
- Single article: clean Republik-style header, no section rubric,
  tags as pills at bottom
- Cover image support (`cover_image:` in front matter):
    - wide mode: full-card banner above text
    - icon mode: small thumbnail right of text with colored card bg
- Library subsection header redesigned with section-colored stripe
- Dates use Swiss DD.MM.YYYY display (ISO retained in datetime attr)
- Custom Tokyo metro photo as demo cover image

content/library/software/eigene-werkzeuge.md

@@ -3,6 +3,7 @@ title: "Warum wir eigene Werkzeuge bauen"
 date: 2026-05-21
 tags: ["software", "praxis", "tools"]
 summary: "DOSSIER und RAPPORT sind keine Lifestyle-Projekte — sie sind Reaktion auf konkrete Lücken."
+color: yuyake
 ---
 
 Wir benutzen viel fremde Software. Aber an zwei Stellen kam keiner der existierenden Werkzeuge an die Praxis heran, die wir brauchten — also haben wir selbst gebaut.