wp refer to resource in main theme from css in child theme code example
Example: create child theme in wordpress
add_action( 'wp_enqueue_scripts', 'my_theme_enqueue_styles' );
function my_theme_enqueue_styles() {
wp_enqueue_style( 'child-style', get_stylesheet_uri(),
array( 'parenthandle' ),
wp_get_theme()->get('Version') // this only works if you have Version in the style header
);
}