[css-flexbox] Fix linking errors.

Author: tabatkins

css-flexbox/Overview.bs

@@ -886,7 +886,7 @@ Implied Minimum Size of Flex Items</h3>
 		<dd>
 			On a <a>flex item</a> whose 'overflow' is ''overflow/visible'' in the <a>main axis</a>,
 			when specified on the <a>flex item's</a> main-axis min-size property,
-			specifies an <dfn>automatic minimum size</dfn>.
+			specifies an <dfn dfn export>automatic minimum size</dfn>.
 
 			In general, the <a>automatic minimum size</a>
 			is the smaller of its <a>content size</a> and its <a>specified size</a>.
@@ -900,25 +900,25 @@ Implied Minimum Size of Flex Items</h3>
 			and are defined below:
 
 			<dl>
-				<dt><var>specified size</var>
+				<dt><dfn dfn noexport>specified size</dfn>
 				<dd>
 					If the item’s computed <a>main size property</a> is <a>definite</a>,
-					then the <var>specified size</var> is that size
+					then the <a>specified size</a> is that size
 					(clamped by its <a>max main size property</a> if it's <a>definite</a>).
 					It is otherwise undefined.
 
-				<dt><var>transferred size</var>
+				<dt><dfn dfn noexport>transferred size</dfn>
 				<dd>
 					If the item has an intrinsic aspect ratio
 					and its computed <a>cross size property</a> is <a>definite</a>,
-					then the <var>transferred size</var> is that size
+					then the <a>transferred size</a> is that size
 					(clamped by its <a lt="min cross size property">min and max cross size properties</a> if they are <a>definite</a>),
 					converted through the aspect ratio.
 					It is otherwise undefined.
 
-				<dt><var>content size</var>
+				<dt><dfn dfn noexport>content size</dfn>
 				<dd>
-					The <var>content size</var> is the <a>min-content size</a> in the <a>main axis</a>,
+					The <a>content size</a> is the <a>min-content size</a> in the <a>main axis</a>,
 					clamped, if it has an aspect ratio, by any <a>definite</a> <a lt="min cross size property">min and max cross size properties</a> converted through the aspect ratio,
 					and then further clamped by the <a>max main size property</a> if that is <a>definite</a>.
 			</dl>
@@ -3745,7 +3745,7 @@ Substantive Changes and Bugfixes</h4>
 			<blockquote>
 				If the item’s <del>computed 'flex-basis' is ''content''
 				and its</del> computed <a>main size property</a> is <a>definite</a>,
-				then the <var>specified size</var> is that size
+				then the <a>specified size</a> is that size
 			</blockquote>
 
 		<li id="change-2014-blockify">