screenshot of source code:
<!DOCTYPE html>
<html xmlns="http://www.w3.org/1999/xhtml" lang="en">
<head>
<title>self-closing strong element</title>
<style>
html { font: 2em/1.2 Calibri, Helvetica Neue, sans-serif }
</style>
</head>
<body>
<p lang="la">Ad astra per <strong/> aspera</p>
<p>To the stars through hardship</p>
</body>
</html>