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/stack.md

@@ -4,6 +4,7 @@ date: 2026-05-23
 weight: 30
 tags: ["software", "stack", "empfehlungen"]
 summary: "Programme und Dienste, die wir Tag für Tag benutzen — kuratiert und kommentiert."
+cover_image: /images/tokyo-metro.jpg
 ---
 
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