Nikolay Yordanov on "[Plugin: W3 Total Cache] Media queries and CSS minify"

WooCommerce uses the optional $media parameter of wp_enqueue_script: https://codex.wordpress.org/Function_Reference/wp_enqueue_style.

W3TC completely ignores this, so I'm guessing that it's a W3TC issue and it's not related to WooCommerce. The solution is to only combine files which have the same media attribute.

See also:

1. https://github.com/woothemes/woocommerce/blob/9a115dc1f4b984e8249c8bbd7a612669055bc249/includes/class-wc-frontend-scripts.php#L38
2. https://developer.mozilla.org/en-US/docs/Web/Guide/CSS/Media_queries