diff --git a/docs/stylesheets/ebiten.css b/docs/stylesheets/ebiten.css
index 25b93589b..52a7a0a5a 100644
--- a/docs/stylesheets/ebiten.css
+++ b/docs/stylesheets/ebiten.css
@@ -75,7 +75,6 @@ footer a {
 }
 
 iframe {
-  background-color: #000;
   border-color: #ddd;
   border-style: solid;
   border-width: 1px;