override the box-shadows on active, checked, and indeterminate states

scss/_custom-forms.scss

@@ -25,11 +25,13 @@
     &:checked ~ .c-indicator {
       color: #fff;
       background-color: #0074d9;
+      @include box-shadow(none);
     }
 
     &:active ~ .c-indicator {
       color: #fff;
       background-color: #84c6ff;
+      @include box-shadow(none);
     }
   }
 
@@ -77,6 +79,7 @@
   input:indeterminate ~ .c-indicator {
     background-color: #0074d9;
     background-image: url(data:image/svg+xml;base64,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);
+    @include box-shadow(none);
   }
 }