How important is it for PHP developers to have a basic understanding of HTML and CSS?

It is essential for PHP developers to have a basic understanding of HTML and CSS as PHP is often used to generate dynamic web content, which is then styled and structured using HTML and CSS. Without this knowledge, developers may struggle to create visually appealing and functional web applications.

<?php
echo "<html>";
echo "<head>";
echo "<style>";
echo "body { background-color: #f0f0f0; }";
echo "</style>";
echo "</head>";
echo "<body>";
echo "<h1>Hello, World!</h1>";
echo "</body>";
echo "</html>";
?>