[css-position-3] Fix typo

Author: fantasai

css-position-3/Overview.bs

@@ -842,7 +842,7 @@ Resolving Automatic Insets: the “Static Position Rectangle”</h4>
 		<dd>
 			The [=static-position rectangle=] of the child of a [=flex container=]
 			corresponds to the [=content edges=] of the [=flex container=].
-			See <a href="https://www.w3.org/TR/css-flexbox-1/#abspos-items">static position of a grid container child</a> in [[!CSS-FLEXBOX-1]].
+			See <a href="https://www.w3.org/TR/css-flexbox-1/#abspos-items">static position of a flex container child</a> in [[!CSS-FLEXBOX-1]].
 
 		<dt>Grid Layout
 		<dd>