<!DOCTYPE html>
<html>
<style>
#o {
 padding: 27660vw;
 outline: thick dotted;
 mask: subtract url(data:image/gif;base64,R0lGODlhAQABAAD/ACwAAAAAAQABAAACADs=), linear-gradient(#FFF, #555);
}
</style>
<script>
document.addEventListener("DOMContentLoaded", function(){
 o.appendChild(document.createElement("div"));
 o.appendChild(document.createElement("frame"));
 o.appendChild(document.createElement("div"));
});
</script>
<span id=o />
</html>