conceal components of admin with css file

i take advantage of woocommerce and woocommerce Product Distributors (https://woocommerce.com/merchandise/product-vendors/)
i would like conceal components of admin with css file "my-admin.css"
I put css file "my-admin.css" on the root of my little one theme wordpress
and use this code in features.php.
This doesn’t work?!?

operate admin_css() {
    $admin_handle = 'admin_css';
    $admin_stylesheet = get_template_directory_uri() . 'my-admin.css';

    wp_enqueue_style($admin_handle, $admin_stylesheet);
}
add_action('admin_print_styles', 'admin_css', 11);

is that this an obselete methodology?
as a result of:
when i take advantage of this different methodology in features.php, it is okay it really works
add_action(‘admin_head’, ‘my_custom_fonts’);

operate my_custom_fonts() {
  echo '<fashion>
    physique, td, textarea, enter, choose {
      font-family: "Lucida Grande";
      font-size: 12px;
    } 
  </fashion>';
}

What do you suppose ?
thanks !!! 🙂