To compress your CSS files with gZIP there are two things that you should do.
First, add the following line to the .htaccess file in your public_html folder:
AddHandler application/x-httpd-php52 .css
By doing this, you allow the server to process .css files through PHP.
Next, add the following lines at the very beginning of your .css file(s):
<?php
ob_start (“ob_gzhandler”);
header(“Content-type: text/css; charset: UTF-8”);
header(“Cache-Control: must-revalidate”);
$offset = 60 * 60 ;
$ExpStr = “Expires: ” .
gmdate(“D, d M Y H:i:s”,
time() + $offset) . ” GMT”;
header($ExpStr);
?>
By doing this, you will enable the gZIP compression for your CSS file. For bigger websites there will be a significant improvement in the loading speed of your pages.
You can check the effect using this optimization tool – http://analyze.websiteoptimization.com/
