diff --git a/source b/source
index 79e90af8a61..9da41e81003 100644
--- a/source
+++ b/source
@@ -123334,12 +123334,12 @@ input[type=image i][align=bottom i], object[align=bottom i] {
 
   <pre><code class="css">@namespace url(http://www.w3.org/1999/xhtml);
 
-summary {
+details > summary:first-of-type {
   display: list-item;
   counter-increment: list-item 0;
   list-style: disclosure-closed inside;
 }
-details[open] > summary {
+details[open] > summary:first-of-type {
   list-style-type: disclosure-open;
 }</code></pre>