Varia: migrate nestedSubMenuPadding mixin

varia/sass/base/legacy/_mixins-master.scss

@@ -107,7 +107,8 @@
 	}
 
 	ul > li > a::before {
-		font-family: $font__body;
+		font-family: $font__body; // For browsers without support for CSS variables.
+		font-family: var( --font-base, $font__body );
 		font-weight: normal;
 		content: "\2013\00a0" counters(submenu, "\2013\00a0", none);
 		counter-increment: submenu