How can I included CSS to a page or a shortcode? [closed]

Question

I would like to add CSS to a page or a shortcode (preferably a shortcode) that would not be dependent on a theme, a plug-in or anything.

I tried adding wp_enqueue_style('[my-css-url]'); to various PHP files but without success. Yet I would expect more proper ways to do it.

I there a way to do that?

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This question is not a duplicate of Enqueue Scripts / Styles when shortcode is present That other question is asked and solved in the context of a plug-in. My question clearly state "independant from plug-ins".

Answer 1

Simply follow the link to the has_shortcode() documentation in the last answer to the duplicate question. There you'll find:

function custom_shortcode_scripts() {
  global $post;
  if ( is_a( $post, 'WP_Post' ) && has_shortcode( $post->post_content, 'custom-shortcode') ) {
      wp_enqueue_script( 'custom-script');
  }
}
add_action( 'wp_enqueue_scripts', 'custom_shortcode_scripts');

For styles this would be:

function custom_shortcode_styles() {
    global $post;
    if ( is_a( $post, 'WP_Post' ) && has_shortcode( $post->post_content, 'custom-shortcode') ) {
        wp_enqueue_style('custom-shortcode-css', get_template_directory_uri() . '/css/custom-shortcode.css');
    }
}
add_action( 'wp_enqueue_scripts', 'custom_shortcode_styles');

Replace custom-shortcode inside has_shortcode() with the shortcode you are actually looking for, then put that snippet in your functions.php or in your plugin and code on!