<style>
.msedge_jstest {
background-color:#ccc;
color:#fff;
}
.msedge_js {
background-color:#f00;
color:#fff;
}
</style>
<div id="my_test_div" class="msedge_jstest">If this is red, JavaScript says this is Microsoft Edge. [THIS WORKS IN FALL 2022]</div>
<script>
if (/Edg/.test(navigator.userAgent) && /Windows/.test(navigator.userAgent))
{
document.getElementById("my_test_div").classList.add("msedge_js");
}
</script>