<!DOCTYPE html>
<div>node</div>
<div inert>inert node</div>
<div inert>inert node</div>
<div inert>inert node</div>
<div inert="foo">inert node</div>

<div id="result"></div>

<style>
div[inert="foo"] {
    background: blue;
}
</style>

<script>
// Test that inertness is properly applied, by checking only the non-inert node is selected
document.execCommand('SelectAll');
result.textContent = window.getSelection().toString().trim();
window.getSelection().removeAllRanges();
</script>