[selectors-4] Per resolution, remove :target-within and replace it with a note about :has(:target). #8357

Author: tabatkins

selectors-4/Overview.bs

@@ -271,11 +271,6 @@ Selectors Overview</h2>
 				<td>an E element being the target of the current URL
 				<td>[[#the-target-pseudo]]
 				<td>3
-			<tr>
-				<td><code>E:target-within</code>
-				<td>an E element that is the target of the current URL or contains an element that does.
-				<td>[[#the-target-within-pseudo]]
-				<td>4
 			<tr>
 				<td><code>E:scope</code>
 				<td>an E element being a [=scoping root=]
@@ -2231,7 +2226,7 @@ The Local Link Pseudo-class: '':local-link''</h3>
 	markup instructions such as <code>&lt;meta http-equiv="..."></code>,
 	or scripting instructions <!-- such as ? -->).
 	UAs must ensure that '':local-link'',
-	as well as the '':target'' and '':target-within'' pseudo-classes below,
+	as well as the '':target'' pseudo-class below,
 	respond correctly to all such changes in state.
 
 <h3 id="the-target-pseudo">
@@ -2274,14 +2269,11 @@ The Target Pseudo-class: '':target''</h3>
 		</pre>
 	</div>
 
-<h3 id="the-target-within-pseudo">
-The Target Container Pseudo-class: '':target-within''</h3>
+	Note: This specification previously defined a <css>:target-within</css> pseudo-class,
+	analogous to '':focus-within''.
+	It was removed in favor of '':has(:target)'',
+	which should hopefully suffice to solve the same use-cases.
 
-	The <dfn id='target-within-pseudo'>:target-within</dfn> pseudo-class
-	applies to any element to which the '':target'' pseudo-class applies
-	as well as to any element whose descendant in the <a>flat tree</a>
-	(including non-element nodes, such as text nodes)
-	matches the conditions for matching '':target''.
 
 <h3 id="the-scope-pseudo">
 The Reference Element Pseudo-class: '':scope''</h3>