diff --git a/static/skin/index.css b/static/skin/index.css
index 769397fe6..a3f21ff2d 100644
--- a/static/skin/index.css
+++ b/static/skin/index.css
@@ -212,7 +212,7 @@ body {
 }
 
 .book__download > span:hover {
-    box-shadow: 0px 5px 5px rgba(0, 0, 0, 0.1)
+    box-shadow: 0 5px 5px rgba(0, 0, 0, 0.1)
 }
 
 .book__description {