diff --git a/assets/course.css b/assets/course.css
index eb36e1c3b..45bce25f7 100644
--- a/assets/course.css
+++ b/assets/course.css
@@ -1,3 +1,18 @@
+@media (prefers-color-scheme: dark) {
+  body {
+    background-color : #002b36;
+    color            : #fdf6e3;
+    font-weight      : lighter;
+  }
+}
+
+@media (prefers-color-scheme: light) {
+  body {
+    background-color : #fdf6e3;
+    color            : #002b36;
+  }
+}
+
 ul li {
     list-style-type: none;
 }