@@ -161,7 +161,6 @@ theme:
   # Necessary for search to work properly
 
   icon:
-    logo: logo
     tag:
       # https://squidfunk.github.io/mkdocs-material/reference/?h=page+icon#setting-the-page-icon
       video: material/video-outline
@@ -328,13 +327,20 @@ plugins:
         release-notes/corporate-memory-25-3/index.md: release-notes/2025/corporate-memory-25-3/index.md
         release-notes/corporate-memory-26-1/index.md: release-notes/2026/corporate-memory-26-1/index.md
         release-notes/corporate-memory-26-2/index.md: release-notes/2026/corporate-memory-26-2/index.md
-  # The two plugins below are inert under Zensical: it neither implements nor
-  # reports them, so social cards and revision dates are missing from the
-  # output. They are kept so the features return automatically once Zensical
-  # maps them. tools/check_zensical_output.py tracks both.
-  # https://squidfunk.github.io/mkdocs-material/setup/setting-up-social-cards/
+  # Natively implemented since Zensical 0.0.67. The colors are required: the
+  # default card layout reads `theme.palette.primary`, which the custom scheme
+  # leaves unset, and the build aborts on it. #0a66a3 is --md-primary-fg-color
+  # in docs/assets/extra.css. The font defaults to Roboto, the site font.
+  # https://zensical.org/docs/setup/social-cards/
   - social:
       cards: true
+      cards_layout_options:
+        background_color: "#0a66a3"
+        color: "#ffffff"
+  # Inert under Zensical: it neither implements nor reports the plugin, so
+  # revision dates are missing from the output. It is kept so the feature
+  # returns automatically once Zensical maps it.
+  # tools/check_zensical_output.py tracks it.
   # https://github.com/timvink/mkdocs-git-revision-date-localized-plugin
   - git-revision-date-localized:
       enable_creation_date: true
 
@@ -36,10 +36,10 @@ pyyaml = "^6.0"
 cmem-cmempy = "^25.3.0"
 pydantic = "^2.11.7"
 jinja2 = "^3.1.6"
-# Zensical is pre-1.0: the caret pin resolves to >=0.0.64,<0.0.65, i.e. a single
+# Zensical is pre-1.0: the caret pin resolves to >=0.0.67,<0.0.68, i.e. a single
 # release. This narrowness is intentional -- bump it manually and re-run
 # `task build` plus `tools/check_zensical_output.py` when doing so.
-zensical = "^0.0.64"
+zensical = "^0.0.67"
 
 [tool.poetry.group.dev.dependencies]
 linkcheckmd = "^1.4.0"
 
@@ -22,7 +22,7 @@
 import re
 import sys
 from pathlib import Path
-from urllib.parse import urljoin
+from urllib.parse import unquote, urljoin, urlparse
 
 import click
 import yaml
@@ -59,6 +59,7 @@
 )
 # <link rel="canonical"> and friends are metadata, not asset loads.
 LINK_META_RE = re.compile(r'rel="(canonical|alternate|manifest)"', re.IGNORECASE)
+OG_IMAGE_RE = re.compile(r'<meta property="og:image" content="([^"]+)"')
 TAGS_LISTING_RE = re.compile(r'<h2 id="tag:([^"]+)"')
 # Zensical (0.0.58+) renders tag chips as links to their /tags/ listing anchor
 # natively; this just asserts every chip's target actually exists there.
@@ -244,11 +245,49 @@ def check_external_assets(pages: list[Path]) -> None:
         report("external-assets", True, "no unexpected third-party hosts", required=True)
 
 
+def check_social_cards(site: Path, pages: list[Path]) -> None:
+    """Every content page carries an og:image whose card was written to site/."""
+    with_card = 0
+    missing: list[str] = []
+    dangling: dict[str, str] = {}
+    for page in pages:
+        body = page.read_text(encoding="utf-8", errors="replace")
+        # Redirect stubs and the 404 page get no card.
+        if REFRESH_RE.search(body) or page == site / "404.html":
+            continue
+        found = OG_IMAGE_RE.search(body)
+        if not found:
+            missing.append(page.relative_to(site).as_posix())
+            continue
+        with_card += 1
+        path = unquote(urlparse(html.unescape(found.group(1))).path)
+        # site_url's path and, in MIKE_DOCS_VERSION builds, the version lead the
+        # URL path but are not directories in site/ - drop segments until it lands.
+        segments = path.strip("/").split("/")
+        if not any((site / "/".join(segments[i:])).is_file() for i in range(len(segments))):
+            dangling.setdefault(path, page.relative_to(site).as_posix())
+
+    report(
+        "social-cards",
+        with_card > 0 and not missing,
+        f"og:image on {with_card} page(s)"
+        if not missing
+        else f"{len(missing)} page(s) without og:image, e.g. " + ", ".join(missing[:3]),
+        required=True,
+    )
+    report(
+        "social-cards-resolve",
+        not dangling,
+        "every og:image card exists in site/"
+        if not dangling
+        else f"{len(dangling)} card(s) missing from site/, e.g. "
+        + ", ".join(f"{u} (on {p})" for u, p in sorted(dangling.items())[:3]),
+        required=True,
+    )
+
+
 def check_pending(site: Path, pages: list[Path]) -> None:
     """Features still missing from Zensical - warn only, never fail."""
-    social = sum(1 for p in pages if 'property="og:image"' in p.read_text(encoding="utf-8", errors="replace"))
-    report("social-cards", social > 0, f"og:image on {social} pages (backlog #37)", required=False)
-
 
     revision = sum(1 for p in pages if "Last update" in p.read_text(encoding="utf-8", errors="replace"))
     report("revision-dates", revision > 0, f"last-update on {revision} pages (backlog #18)", required=False)
@@ -283,6 +322,7 @@ def check_zensical_output(site_dir: str, config_file: str) -> None:
     check_comments(site, pages)
     check_external_assets(pages)
     check_tag_chip_links(site, pages)
+    check_social_cards(site, pages)
     print()
     check_pending(site, pages)
     print()