diff --git a/doc/doc.css b/doc/doc.css
index 9095707..0edbf9a 100644
--- a/doc/doc.css
+++ b/doc/doc.css
@@ -1,7 +1,7 @@
 div.section {
   margin-left: 2em;
   max-width: 40em;
-  border-left-style: solid;
+  border-left-style: hidden;
   border-width: 1px;
   background-color: #FFF;
 }