What does<p>.menu + .alert-danger { margin-top: -16px; }<p>do that<p>.menu + .alert.danger { margin-top: -16px; }<p>doesn&#x27;t? Isn&#x27;t &quot;alert-danger&quot; redundant? It means that, in practice, you need to do something like:<p>.alert-danger, .list-danger, .heading-danger, .foo-danger, .bar-danger, .hum-danger { color: red; }<p>instead of just<p>.danger { color: red; }