What are common issues when trying to center PHP output in HTML?

Common issues when trying to center PHP output in HTML include not properly using CSS styles to center the content or not wrapping the output in a container with the correct styling. To center PHP output in HTML, you can use CSS styles such as text-align: center; or margin: 0 auto; on a container element that wraps around the PHP output.

<!DOCTYPE html>
<html>
<head>
    <style>
        .center {
            text-align: center;
        }
    </style>
</head>
<body>
    <div class="center">
        <?php
            echo "This content is centered using CSS in PHP output.";
        ?>
    </div>
</body>
</html>