Add "virtual" label before the button group of keyboard slider. #50

sass/app.scss

@@ -146,6 +146,25 @@ ul {
   }
 }
 
+.uhk {
+  &__layer-switcher {
+    &--wrapper {
+      position: relative;
+
+      &:before {
+        content: 'Layers: ';
+        display: inline-block;
+        position: absolute;
+        bottom: -0.3em;
+        right: 100%;
+        font-size: 2.4rem;
+        padding-right: .25em;
+        margin: 0;
+      }
+    }
+  }
+}
+
 .keyboard-slider {
   position: relative;
   overflow: hidden;