Need access to .panel-grid wrapper

For the moment, I hacked a workaround in javascript (jquery).

Here it is, in case it helps someone else:
you need a div.maximum-width that wraps around the Page builder area.
Then on the specific row that should be full-width, add classes “background full” in the row editor.
In my CSS file, I have background-color classes (.background–blue for example) that I add to the panel-grid div wrapper, generated by PB.

// make some width full background (pagebuilder does not allow it)
var window_width = $(window).width();
var max_width = $('.maximum-width').width();
var delta_width = window_width - max_width;
var correctif = (delta_width/2);
var el_classes, colour_class;
$('.background.full').each(function(){
	el_classes = $(this).attr("class").split(' ');
	el_classes.forEach(function(e){
		if (e.beginsWith('background--')){
			colour_class = e;
		}
	});
	var row = $(this).parent('.panel-grid');
	row.addClass(colour_class);
	row.css({	
           	width: window_width, 
		maxWidth: window_width, 
		marginLeft: -correctif, 
		paddingLeft: correctif,
		paddingRight: correctif
	});
});