Index: wp-content/themes/twentythirteen/style.css
===================================================================
--- wp-content/themes/twentythirteen/style.css	(revision 23465)
+++ wp-content/themes/twentythirteen/style.css	(working copy)
@@ -2830,8 +2830,18 @@
 }
 
 @media (max-width: 643px) {
+	#masthead {
+		background-position: center;
+	}
+
+	.site-header hgroup {
+		min-height: 0;
+		padding: 20px;
+	}
+
 	.site-title {
 		font-size: 30px;
+		padding-top: 0;
 	}
 
 	.navbar-fixed .site-title,