diff --git a/docs/css/main.css b/docs/css/main.css
index 175e8004fca0e1511bcf29be9be9eed84f861532..7f1e99bf672244c373e0561bd243d8c15dfc081e 100755
--- a/docs/css/main.css
+++ b/docs/css/main.css
@@ -195,7 +195,7 @@ a.anchorjs-link:hover { text-decoration: none; }
   margin-top: 0px;
   width: 210px;
   float: left;
-  position: absolute;
+  position: fixed;
 }
 
 .left-menu {
@@ -286,4 +286,4 @@ label[for="nav-trigger"]:hover {
     margin-left: -215px;
   }
 
-}
\ No newline at end of file
+}