<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta http-equiv="X-UA-Compatible" content="IE=edge">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Certificate</title>
</head>
<body>
    Dear <?php echo $content; ?>,
    <br><br>
    <p>
        You have completed <?php echo $certificate_name; ?>.
        Find your certificate attached.
    </p>
    <p>
        Thank you for your participation.
    </p>
</body>
</html>