Ixion: Fix cover images with fixed background. See #499

ixion/blocks.css

@@ -27,13 +27,10 @@ Description: Used to style Gutenberg Blocks.
 /* Full Width */
 
 .no-sidebar .alignfull {
-	width: 100vw;
-	max-width: 100vw;
-	margin-left: 0;
-	margin-right: 0;
 	position: relative;
-	left: 50%;
-	transform: translateX( -50% );
+	min-width: 100vw;
+	margin-left: 50%;
+	left: -50vw;
 }
 
 .no-sidebar .wp-block-columns.alignfull,