diff -r d4ec02c51c91 -r af15590802a4 assets/stylesheets/bootstrap/mixins/_labels.scss
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/assets/stylesheets/bootstrap/mixins/_labels.scss	Thu Jun 15 12:17:09 2017 +0200
@@ -0,0 +1,12 @@
+// Labels
+
+@mixin label-variant($color) {
+  background-color: $color;
+
+  &[href] {
+    &:hover,
+    &:focus {
+      background-color: darken($color, 10%);
+    }
+  }
+}