adapt.css: add more visual structure

adapt.css

@@ -118,10 +118,12 @@ appears on the left side of the page.
   background: #ccc;
 }
 #menu .sidehead {}
-#menu .pure-menu ul {padding-left: 12px;}
-/* Remove all background/borders, since we are applying them to #menu.*/
-#menu .pure-menu,
 #menu .pure-menu ul {
+	margin-left: 0.5em;
+	border-left: 8px solid #ddd;
+}
+/* Remove all background/borders, since we are applying them to #menu.*/
+#menu .pure-menu {
   border: none; background: transparent; }
 /* This styles the selected menu item `<li>`. */
 #menu .pure-menu-selected,