diff --git a/css/21.css b/css/21.css
index 6ba5da2..550c50a 100644
--- a/css/21.css
+++ b/css/21.css
@@ -98,23 +98,6 @@ p>code {
 	margin: 1em;
 }
 
-.btn-github {
-	background-color: hsl(29, 0%, 29%) !important;
-	background-repeat: repeat-x;
-	filter: progid:DXImageTransform.Microsoft.gradient(startColorstr="#727272", endColorstr="#494949");
-	background-image: -khtml-gradient(linear, left top, left bottom, from(#727272), to(#494949));
-	background-image: -moz-linear-gradient(top, #727272, #494949);
-	background-image: -ms-linear-gradient(top, #727272, #494949);
-	background-image: -webkit-gradient(linear, left top, left bottom, color-stop(0%, #727272), color-stop(100%, #494949));
-	background-image: -webkit-linear-gradient(top, #727272, #494949);
-	background-image: -o-linear-gradient(top, #727272, #494949);
-	background-image: linear-gradient(#727272, #494949);
-	border-color: #494949 #494949 hsl(29, 0%, 25%);
-	color: #fff !important;
-	text-shadow: 0 -1px 0 rgba(0, 0, 0, 0.26);
-	-webkit-font-smoothing: antialiased;
-}
-
 ul.thumbnails li {
 	margin-bottom: 25px;
 }