diff --git a/courses/stylesheets/custom.css b/courses/stylesheets/custom.css
new file mode 100644
index 0000000..7b56339
--- /dev/null
+++ b/courses/stylesheets/custom.css
@@ -0,0 +1 @@
+div.md-content img { border: 4px solid #ddd; padding: 12px; }
\ No newline at end of file
diff --git a/mkdocs.yml b/mkdocs.yml
index ea1e821..54bfd0e 100644
--- a/mkdocs.yml
+++ b/mkdocs.yml
@@ -5,6 +5,8 @@ theme:
   logo: img/sos.png
   favicon: img/favicon.ico
   custom_dir: overrides
+extra_css:
+    - stylesheets/custom.css
 nav:
 - Home: index.md
 - Fundamentals Series: