Custom style.css

I am trying to style 404.php file and i have a custom style-sheet for that and want to use this particular stylesheet for this page only.
So i registered the stylesheet in the function.php of the theme using the following code:

function script_and_style()
	{
    wp_register_style( '404-stylesheet', get_stylesheet_directory_uri() . '/css/style.css', array(), '', 'all' );
	}
add_action( 'wp_enqueue_scripts', 'script_and_style', 999 );

function change_style() {
   if ( is_page( '404.php' ) )
   {
     wp_enqueue_style( '404-stylesheet' );
   }
}
add_action( 'wp_enqueue_scripts', 'change_style', 999 );

but when i load the 404 page its not loading the stylesheet.
can anyone help me.
my website: