Index: wp-content/themes/twentyeleven/style.css
===================================================================
--- wp-content/themes/twentyeleven/style.css	(revision 23297)
+++ wp-content/themes/twentyeleven/style.css	(working copy)
@@ -985,6 +985,10 @@
 .entry-content .twitter-tweet-rendered {
 	max-width: 100% !important; /* Override the Twitter embed fixed width */
 }
+.gist .gist-file .gist-data .line_numbers span { /* Corrects line number misalignment in GitHub Gist embeds */
+	font-size: 13px;
+	line-height: 1.5;
+}
 
 /* Password Protected Posts */
 .post-password-required .entry-header .comments-link {
Index: wp-content/themes/twentytwelve/style.css
===================================================================
--- wp-content/themes/twentytwelve/style.css	(revision 23297)
+++ wp-content/themes/twentytwelve/style.css	(working copy)
@@ -341,6 +341,9 @@
 .entry-content .twitter-tweet-rendered {
 	max-width: 100% !important; /* Override the Twitter embed fixed width */
 }
+.gist .gist-file .gist-data .line_numbers span {
+	line-height: 1.714285714; /* Corrects line number misalignment in GitHub Gist embeds */
+}
 
 /* Images */
 .alignleft {