Compress Mltiple CSS Files using PHP

<?php
header('Content-type: text/css');
ob_start('compress_css');
 
function compress_css($buffer) {
  /* remove comments in css file */
  $buffer = preg_replace('!/\*[^*]*\*+([^/][^*]*\*+)*/!', '', $buffer);
  /* also remove tabs, spaces, newlines, etc. */
  $buffer = str_replace(array("\r", "\n", "\r\n", "\t", '  ', '    ', '    '), '', $buffer);
  return $buffer;
}
 
/* a list of your css files */
include('style.css');
include('css/menu.css');
include('css/typography.css');
include('css/print.css');
include('inc/css/footer.css');
 
ob_end_flush();
?>