fix ordering instruction mixup

Author: argyleink

css-nesting-1/Overview.bs

@@ -466,7 +466,7 @@ Nesting Conditional Rules {#conditionals}
 -----------------------------------------------
 
 	A style rule can have any number of <a>conditional rules</a> inside of it, of any type,
-	with rules required to come before declarations (see <a href="#mixing">Mixing Nesting Rules and Declarations</a>).
+	with rules required to come after declarations (see <a href="#mixing">Mixing Nesting Rules and Declarations</a>).
 
 	If there are only rules in the nested conditional, the nesting context is adopted.