Added comment explaining why there is no mixin here

scss/_custom-forms.scss

@@ -26,6 +26,7 @@
     }
 
     &:focus ~ .c-indicator {
+      // the mixin is not used here to make sure there is feedback
       box-shadow: 0 0 0 .075rem #fff, 0 0 0 .2rem #0074d9;
     }