twenty_twenty_one_body_classes( array $classes ): array

18function twenty_twenty_one_body_classes( $classes ) {19 20	// Helps detect if JS is enabled or not.21	$classes[] = 'no-js';22 23	// Adds `singular` to singular pages, and `hfeed` to all other pages.24	$classes[] = is_singular() ? 'singular' : 'hfeed';25 26	// Add a body class if main navigation is active.27	if ( has_nav_menu( 'primary' ) ) {28		$classes[] = 'has-main-navigation';29	}30 31	// Add a body class if there are no footer widgets.32	if ( ! is_active_sidebar( 'sidebar-1' ) ) {33		$classes[] = 'no-widgets';34	}35 36	return $classes;37}