diff --git a/_css/nav.css b/_css/nav.css
index 9f8861d..b4397d7 100644
--- a/_css/nav.css
+++ b/_css/nav.css
@@ -15,6 +15,7 @@ ul.topnav {
   padding: 0;
   overflow: hidden;
   background-color: #333;
+  z-index: 10;
 }
 
 ul.topnav li {float: left;}