diff --git a/src/generator/generator.py b/src/generator/generator.py
index e41c772..51acf31 100644
--- a/src/generator/generator.py
+++ b/src/generator/generator.py
@@ -260,13 +260,32 @@ class GhostPublisher:
                             tags: list[str] | None = None) -> dict:
         import aiohttp as _aio
         import markdown as _md
+
         clean = _strip_researchowl_header(markdown_content)
         html = _md.markdown(clean, extensions=["extra"])
+
+        logger.info("Ghost publish_draft", html_length=len(html),
+                    html_preview=html[:200])
+
+        if not html.strip():
+            raise ValueError("Ghost: HTML vacío tras conversión markdown — contenido no enviado")
+
+        # Ghost 5.x (Lexical editor): el campo "html" es solo de lectura en la API.
+        # La forma fiable de enviar HTML arbitrario es via mobiledoc con HTML card,
+        # que Ghost acepta en todas las versiones de v5 y renderiza sin conversión.
+        mobiledoc = json.dumps({
+            "version": "0.3.1",
+            "atoms": [],
+            "cards": [["html", {"html": html}]],
+            "markups": [],
+            "sections": [[10, 0]],
+        })
+
         token = self._make_token()
         body = {
             "posts": [{
                 "title": title,
-                "html": html,
+                "mobiledoc": mobiledoc,
                 "status": "draft",
                 "tags": [{"name": t} for t in (tags or ["investigacion"])],
             }]