Overriding front.css and print.css via child theme.

I’ve managed to modify the invoice template by copying “generated_invoice.php” file into my child theme folder. Still I cannot make my custom css work for that. Looks like “front.css” and “print.css” files are still loaded from the plugin folder, not my child theme folder.

I would appreciate a hint where should I put those css files to let them override the plugin files.