[css-ruby] Fix links

Author: fantasai

css-ruby/Overview.bs

@@ -17,6 +17,7 @@ Abstract: “Ruby”, a form of interlinear annotation, are short runs of text a
 Abstract: They are typically used in East Asian documents to indicate pronunciation or to provide a short annotation.
 Abstract: This module describes the rendering model and formatting controls related to displaying ruby annotations in CSS.
 Ignored terms: internal table elements, characters
+Ignored vars: any
 </pre>
 
 <!--
@@ -37,7 +38,7 @@ Introduction</h2>
 <h3 id="placement">
 Module interactions</h3>
 
-	<p>This module extends the inline box model of CSS Level 2 [[!CSS21]]
+	<p>This module extends the inline box model of CSS Level 2 [[!CSS2]]
 	to support ruby.
 
 	<p>None of the properties in this module apply to the <code>::first-line</code> or
@@ -46,7 +47,7 @@ Module interactions</h3>
 <h3 id="values">
 Values</h3>
 
-	This specification follows the <a href="https://www.w3.org/TR/CSS21/about.html#property-defs">CSS property definition conventions</a> from [[!CSS2]].
+	This specification follows the <a href="https://www.w3.org/TR/CSS2/about.html#property-defs">CSS property definition conventions</a> from [[!CSS2]].
 	Value types not defined in this specification are defined in CSS Values & Units [[!CSS-VALUES-3]].
 	Other CSS modules may expand the definitions of these value types.
 
@@ -231,7 +232,7 @@ Non-Inline Ruby</h4>
 
 	<p class="note">
 	Note that absolute positioning or floating an element causes its 'display' value
-	to compute to a block-level equivalent. (See [[!CSS3-DISPLAY]] or [[!CSS21]] section 9.7.)
+	to compute to a block-level equivalent. (See [[!CSS-DISPLAY-3]] or [[!CSS2]] section 9.7.)
 	For the <i>internal ruby display types</i>,
 	this causes their 'display' value to compute to ''display/block''.
 
@@ -241,7 +242,7 @@ Anonymous Ruby Box Generation</h3>
 	<p>The CSS model does not require that the document language
 	include elements that correspond to each of these components.
 	Missing parts of the structure are implied through the anonymous box generation rules
-	<a href="https://www.w3.org/TR/CSS21/tables.html#anonymous-boxes">similar to those used to normalize tables</a>. [[!CSS21]]
+	<a href="https://www.w3.org/TR/CSS2/tables.html#anonymous-boxes">similar to those used to normalize tables</a>. [[!CSS2]]
 
 	<ol>
 
@@ -260,7 +261,7 @@ Anonymous Ruby Box Generation</h3>
 			computes to ''inline-block''.
 
 		<li id="anon-gen-anon-ruby"><strong>Generate anonymous ruby containers</strong>:
-			Any <a href="https://www.w3.org/TR/CSS21/tables.html#anonymous-boxes">consecutive</a> sequence of
+			Any <a href="https://www.w3.org/TR/CSS2/tables.html#anonymous-boxes">consecutive</a> sequence of
 			improperly-contained
 			<i>ruby base containers</i>,
 			<i>ruby annotation containers</i>,
@@ -829,7 +830,7 @@ Line Spacing</h3>
 	<p>The 'line-height' property controls spacing between lines in CSS.
 	When inline content on line is shorter than the 'line-height',
 	half-leading is added on either side of the content,
-	as specified in <a href="https://www.w3.org/TR/CSS21/visudet.html#line-height">CSS2.1&sect;10.8</a>. [[!CSS21]]
+	as specified in <a href="https://www.w3.org/TR/CSS2/visudet.html#line-height">CSS2.1&sect;10.8</a>. [[!CSS2]]
 
 	<p>In order to ensure consistent spacing of lines,
 	documents with ruby typically ensure that the 'line-height' is large enough