make codeblock folding has a larger clickable area

include/style/codeblock.styl

@@ -13,7 +13,7 @@ figure.highlight
     &.folded
         .highlight-body
             height: 0
-    
+
     .copy
         opacity: .7
 
@@ -90,6 +90,14 @@ figure.highlight
         min-width: inherit
         border-radius: inherit
 
+figure.highlight.folded
+  figcaption
+    cursor: pointer
+
+figure.highlight.unfolded
+  figcaption
+    cursor: pointer
+
 /* ---------------------------------
  *        Fix Gist Snippet
  * --------------------------------- */

source/js/main.js

@@ -111,7 +111,7 @@
                 toggleFold(this, fold === 'folded');
             });
 
-            $('figure.highlight figcaption .fold').click(function() {
+            $('figure.highlight figcaption').click(function() {
                 const $code = $(this).closest('figure.highlight');
                 toggleFold($code.eq(0), !$code.hasClass('folded'));
             });