Make the mobile menu slide up and down

gistfile1.txt

<script>
    jQuery( document ).ready( function( $ ) {
		$( '.menu-toggle' ).addClass( 'closed' );
		$( document ).on( 'click', '.menu-toggle.closed', function() {
			var sub = $( this ).next( '.main-nav' ).children( 'ul' );
			sub.hide();
			sub.slideDown();
			$( this ).removeClass( 'closed' );
			$( this ).addClass( 'opened' );
		});
		$( document ).on( 'click', '.menu-toggle.opened', function() {
			var sub = $( this ).next( '.main-nav' ).children( 'ul' );
			sub.slideUp();
			$( this ).removeClass( 'opened' );
			$( this ).addClass( 'closed' );
		});
		

    });
</script>