use function wp_enqueue_style code example

Example 1: wp_enqueue_style

wp_enqueue_style( 'slider', get_template_directory_uri() . '/css/slider.css',false,'1.1','all');

Example 2: wp enqueue style

wp_enqueue_style( 'my-style', get_template_directory_uri() . '/css/my-style.css', false, '1.0', 'all' ); // Inside a parent theme
wp_enqueue_style( 'my-style', get_stylesheet_directory_uri() . '/css/my-style.css', false, '1.0', 'all' ); // Inside a child theme
wp_enqueue_style( 'my-style', plugins_url( '/css/my-style.css', __FILE__ ), false,