[css-contain-1] Fix grammar

frivoal · frivoal · commit 4b16b66910c8 · 2018-02-17T10:12:27.000+09:00
diff --git a/css-contain-1/Overview.bs b/css-contain-1/Overview.bs
@@ -252,7 +252,7 @@ Layout Containment</h3>
 <h3 id='containment-style'>
 Style Containment</h3>
 
-	Giving an element <dfn export>style containment</dfn> has the following effects:
+	Giving an element <dfn export>style containment</dfn> has the following effect:
 
 	1. The 'counter-increment', 'counter-set', and <a property spec=css2>content</a> (for the purpose of ''content/open-quote''/etc values) properties
 	    must be <a for=property>scoped</a> to the element's sub-tree.
