add_action( 'wp_print_styles', 'lit_deregister_editor_styles', 100 );
/**
 * Removes WP block editor styles
 */
function lit_deregister_editor_styles() {

  	if ( !is_singular('post') ) { // If isn't a single post, remove access block libary CSS
	    wp_dequeue_style( 'wp-block-library' );
	  }

}