How can PHP beginners optimize their websites for mobile devices, such as iPhones?

PHP beginners can optimize their websites for mobile devices, such as iPhones, by using responsive design techniques. This involves creating flexible layouts that adjust to different screen sizes, ensuring that content is displayed properly on various devices. Additionally, developers can use media queries to target specific device characteristics and apply custom styles accordingly.

// Example of using media queries in PHP to optimize website for mobile devices

echo '<style>';
echo '@media only screen and (max-width: 768px) {';
echo '  /* CSS styles for devices with max-width of 768px (e.g., iPhones) */';
echo '  body {';
echo '    font-size: 14px;';
echo '  }';
echo '}';
echo '</style>';