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

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!