diff --git a/.idea/jekyll-theme-bluelib.iml b/.idea/jekyll-theme-bluelib.iml
index 87a4e1a..b8fd174 100644
--- a/.idea/jekyll-theme-bluelib.iml
+++ b/.idea/jekyll-theme-bluelib.iml
@@ -11,6 +11,7 @@
+
@@ -39,6 +40,6 @@
-
+
\ No newline at end of file
diff --git a/README.md b/README.md
index fb7eb69..d9c431b 100644
--- a/README.md
+++ b/README.md
@@ -48,6 +48,7 @@ In particular, it ``s in the following order:
1. The `skeleton.root.css` from the latest version of bluelib
2. The bluelib `root` target defined in the `bluelib` variable of `_config.yml` (`site.bluelib`)
3. The bluelib `root` target defined in the `bluelib` variable of the Front Matter of the page (`page.bluelib`)
+4. The CSS files specified in the `extra_css` array of `_config.yml` (`site.extra_css`)
### `base`
diff --git a/_layouts/default.html b/_layouts/default.html
index c87aff3..f48b6a3 100644
--- a/_layouts/default.html
+++ b/_layouts/default.html
@@ -1,8 +1,13 @@