diff --git a/.gitea/workflows/publish.yml b/.gitea/workflows/publish.yml
index 10547e4..de2fc58 100644
--- a/.gitea/workflows/publish.yml
+++ b/.gitea/workflows/publish.yml
@@ -39,13 +39,27 @@ jobs:
           fi
 
       - name: Render
-        run: "$HOME/opt/quarto-${QUARTO_VERSION}/bin/quarto render"
+        run: |
+          set -e
+          cd "$GITHUB_WORKSPACE"
+          QUARTO="$HOME/opt/quarto-${QUARTO_VERSION}/bin/quarto"
+          echo "pwd=$(pwd)"
+          ls -la
+          "$QUARTO" --version
+          "$QUARTO" render 2>&1
+          echo "--- obsah _site ---"
+          find _site -maxdepth 2 2>/dev/null | head -30
+          # pojistka: prázdný build nesmí přepsat publikovaný web
+          test -f _site/index.html
 
       - name: Deploy to gh-pages
         env:
           TOKEN: ${{ secrets.GITEA_TOKEN }}
         run: |
           set -e
+          cd "$GITHUB_WORKSPACE"
+          # pojistka: bez index.html v _site se nepublikuje nic
+          test -f _site/index.html
           REMOTE="https://x-access-token:${TOKEN}@${GITEA_HOST}/${GITHUB_REPOSITORY}.git"
           WT="/tmp/gh-pages-${GITHUB_RUN_ID}"
           trap 'rm -rf "$WT"' EXIT