diff --git a/doc/docs.css b/doc/docs.css
index 720195d642..01bce0d015 100644
--- a/doc/docs.css
+++ b/doc/docs.css
@@ -108,6 +108,10 @@ h3 {
    font-size: 0.9em;
 }
 
+.topnav ul ul li li li {
+   font-size: 1em;
+}
+
 .bottomnav {
     background-color:#FBFBEE;
     border:1px solid #CCCCCC;
@@ -230,4 +234,4 @@ code {
   .bottomnav { display: none; }
   .totoc { display: none; }
   .topnav ul li a { text-decoration: none; color: #000; }
-}
\ No newline at end of file
+}