<style>
@namespace s "http://www.w3.org/2000/svg";

body * {
    display: block;
    width: 100px;
    border: 1px solid black;
}
body |* {
    width: 200px !important;
}
body *|* {
    height: 100px;
}
body s|* {
    border-width: 10px;
}
</style>
<svg></svg>
<math></math>
<div></div>