<!doctype html>
<style>
#non-modal {
    position: static;
}
</style>
<p>Test that a non-top layer element doesn't share style with a top layer
element. The test passes if you see two boxes.</p>
<dialog id="non-modal" open></dialog>
<dialog id="modal"></dialog>
<script>
document.querySelector('#modal').showModal();
</script>