diff --git a/.github/workflows/accessibility.yml b/.github/workflows/accessibility.yml
index 9ad5f924..6f1732c7 100644
--- a/.github/workflows/accessibility.yml
+++ b/.github/workflows/accessibility.yml
@@ -10,6 +10,8 @@ jobs:
       image: mcr.microsoft.com/playwright:v1.42.1-jammy # includes Chromium, Node, and tools
     steps:
       - uses: actions/checkout@v3
+        with:
+          fetch-depth: 0
 
       - name: Set up Python 3.11
         uses: actions/setup-python@v4
@@ -61,7 +63,7 @@ jobs:
           echo "[" > pa11y_targets.json
           first=true
 
-          git fetch origin ${{ github.base_ref }}
+          git fetch --no-tags --prune --progress --depth=100 origin ${{ github.base_ref }}
           git diff --name-only origin/${{ github.base_ref }}...HEAD | grep -E "\.md$|\.ipynb$" > changed_files.txt || true
           echo "Changed source files:"
           cat changed_files.txt || echo "None"
diff --git a/short_courses/r_environments.ipynb b/short_courses/r_environments.ipynb
index 7dda10e8..f38df20a 100644
--- a/short_courses/r_environments.ipynb
+++ b/short_courses/r_environments.ipynb
@@ -8,7 +8,7 @@
     "\n",
     "```{card}\n",
     "\n",
-    "<div class=\"alert alert-block alert-info\">\n",
+    "<div class=\"alert alert-block\" style=\"background-color: #f2f2f2;\">\n",
     "\n",
     "**Author:** Amy Heather (GitHub: [amyheather](https://github.com/amyheather), ORCID: [0000-0002-6596-3479](https://orcid.org/0000-0002-6596-3479)).\n",
     "\n",
@@ -635,10 +635,24 @@
   }
  ],
  "metadata": {
+  "kernelspec": {
+   "display_name": "Python 3 (ipykernel)",
+   "language": "python",
+   "name": "python3"
+  },
   "language_info": {
-   "name": "python"
+   "codemirror_mode": {
+    "name": "ipython",
+    "version": 3
+   },
+   "file_extension": ".py",
+   "mimetype": "text/x-python",
+   "name": "python",
+   "nbconvert_exporter": "python",
+   "pygments_lexer": "ipython3",
+   "version": "3.9.19"
   }
  },
  "nbformat": 4,
- "nbformat_minor": 2
+ "nbformat_minor": 4
 }