<html>
<head>
<style>
::grammar-error {
text-decoration: underline red;
color: red;
}
</style>
</head>
<body>
<h1>Demo of ::grammar-error</h1>
<p contenteditable="true" spellcheck="true">This is a praggagraph. It is editable. Try to change the text.</p>
</body>
</html>