The only way I could figure out how to make a child theme work without breaking the responsive design is to hack interface_scripts_styles_method and change
wp_enqueue_style( ‘interface_style’, get_stylesheet_uri());
to
wp_enqueue_style( ‘interface_style’, get_template_directory_uri().’/style.css’);
It’s obviously the wrong approach to change the parent theme’s functions.php … if at some point you can let me know the right way to create a child theme without touching your functions.php and while preserving responsive functionality, that would be great.
Thanks!