Correctly xref :lang() pseudo-class

Fixes https://www.w3.org/Bugs/Public/show_bug.cgi?id=25738.

index.bs

@@ -4389,9 +4389,9 @@ being treated as follows:</p>
  classes</a>.</p></li> <!-- ok, this isn't especially well-defined, but the Selectors spec doesn't
  really give one much to go on here. -->
 
- <li><p>For the purposes of the <code lt="selector-lang">:lang()</code> pseudo-class, <a lt="WebVTT
- Internal Node Object">WebVTT Internal Node Objects</a> have the language described as the <a>WebVTT
- Node Object's applicable language</a>.</p></li>
+ <li><p>For the purposes of the '':lang()'' pseudo-class, <a lt="WebVTT Internal Node Object">WebVTT
+ Internal Node Objects</a> have the language described as the <a>WebVTT Node Object's applicable
+ language</a>.</p></li>
 
  <li><p>For the purposes of ID selector matching, <a lt="list of WebVTT Node Objects">lists of
  WebVTT Node Objects</a> have the ID given by the cue's <a>text track cue identifier</a>, if

index.html

@@ -4157,8 +4157,9 @@ <h5 class="heading settled" data-level="6.1.2.1" id="the-cue-pseudo-element"><sp
  Internal Node Objects</a> have the classes described as the <a data-link-type="dfn" href="#webvtt-node-objects-applicable-classes">WebVTT Node Object’s applicable
  classes</a>.</p>
     <li>
-     <p>For the purposes of the <code data-lt="selector-lang">:lang()</code> pseudo-class, <a data-link-type="dfn" href="#webvtt-internal-node-object">WebVTT Internal Node Objects</a> have the language described as the <a data-link-type="dfn" href="#webvtt-node-objects-applicable-language">WebVTT
- Node Object’s applicable language</a>.</p>
+     <p>For the purposes of the <a class="css" data-link-type="maybe" href="https://drafts.csswg.org/selectors-4/#lang-pseudo">:lang()</a> pseudo-class, <a data-link-type="dfn" href="#webvtt-internal-node-object">WebVTT
+ Internal Node Objects</a> have the language described as the <a data-link-type="dfn" href="#webvtt-node-objects-applicable-language">WebVTT Node Object’s applicable
+ language</a>.</p>
     <li>
      <p>For the purposes of ID selector matching, <a data-link-type="dfn" href="#list-of-webvtt-node-objects">lists of
  WebVTT Node Objects</a> have the ID given by the cue’s <a data-link-type="dfn" href="https://html.spec.whatwg.org/multipage/embedded-content.html#text-track-cue-identifier">text track cue identifier</a>, if
@@ -5053,6 +5054,11 @@ <h3 class="no-num heading settled" id="index-defined-elsewhere"><span class="con
      <li><a href="https://html.spec.whatwg.org/multipage/semantics.html#the-u-element">u</a>
      <li><a href="https://html.spec.whatwg.org/multipage/embedded-content.html#video">video</a>
     </ul>
+   <li>
+    <a data-link-type="biblio" href="#biblio-selectors-4">[selectors-4]</a> defines the following terms:
+    <ul>
+     <li><a href="https://drafts.csswg.org/selectors-4/#lang-pseudo">:lang()</a>
+    </ul>
    <li>
     <a data-link-type="biblio" href="#biblio-svg2">[SVG2]</a> defines the following terms:
     <ul>
@@ -5112,6 +5118,8 @@ <h3 class="no-num heading settled" id="normative"><span class="content">Normativ
    <dd>S. Bradner. <a href="https://tools.ietf.org/html/rfc2119">Key words for use in RFCs to Indicate Requirement Levels</a>. March 1997. Best Current Practice. URL: <a href="https://tools.ietf.org/html/rfc2119">https://tools.ietf.org/html/rfc2119</a>
    <dt id="biblio-rfc3629"><a class="self-link" href="#biblio-rfc3629"></a>[RFC3629]
    <dd>F. Yergeau. <a href="https://tools.ietf.org/html/rfc3629">UTF-8, a transformation format of ISO 10646</a>. November 2003. Internet Standard. URL: <a href="https://tools.ietf.org/html/rfc3629">https://tools.ietf.org/html/rfc3629</a>
+   <dt id="biblio-selectors-4"><a class="self-link" href="#biblio-selectors-4"></a>[SELECTORS-4]
+   <dd>Selectors Level 4 URL: <a href="https://drafts.csswg.org/selectors-4/">https://drafts.csswg.org/selectors-4/</a>
    <dt id="biblio-selectors4"><a class="self-link" href="#biblio-selectors4"></a>[SELECTORS4]
    <dd>Elika Etemad; Tab Atkins Jr.. <a href="http://www.w3.org/TR/selectors4/">Selectors Level 4</a>. 2 May 2013. WD. URL: <a href="http://www.w3.org/TR/selectors4/">http://www.w3.org/TR/selectors4/</a>
   </dl>