Index: src/wp-includes/css/buttons.css
===================================================================
--- src/wp-includes/css/buttons.css	(revision 29938)
+++ src/wp-includes/css/buttons.css	(working copy)
@@ -321,6 +321,10 @@
 		margin-bottom: 4px;
 	}
 
+	.theme-install-overlay .button.theme-install{
+		padding: 2px 14px;
+	}
+
 	#media-upload.wp-core-ui .button {
 		padding: 0 10px 1px;
 		height: 24px;