In order to enable merging CSS files, please replace this part of the code:
$config["tweaks"]["join_css"] = false;
with this one:
$config["tweaks"]["join_css"] = true;
in the “config.local.php” file located in the root directory of your CS-Cart installation.
$config["tweaks"]["js_compression"] = false;
$config["tweaks"]["js_compression"] = true;
CS-Cart Support Team