What are common compatibility issues between different browsers when using CSS in PHP?

Common compatibility issues between different browsers when using CSS in PHP include differences in rendering, handling of CSS properties, and support for certain CSS features. To solve these issues, it is important to use vendor prefixes, CSS resets, and feature detection techniques to ensure consistent styling across browsers.

<?php
echo '<style>';
echo 'body {';
echo '  -webkit-border-radius: 5px;';
echo '  -moz-border-radius: 5px;';
echo '  border-radius: 5px;';
echo '}';
echo '</style>';
?>