[css-align] Clarify that “matches” means “is parallel to”. Fixes #1423.

Author: fantasai

css-align/Overview.bs

@@ -881,7 +881,7 @@ Baseline Content-Alignment</h3>
 		<dt>Table Cells:
 		<dd>
 			A <a>table cell</a> participates in first (last) <a>baseline content-alignment</a>
-			in its startmost (endmost) row or column (whichever matches its <a>inline axis</a>)
+			in its startmost (endmost) row or column (whichever is parallel to its <a>inline axis</a>)
 			if its computed 'align-content' is ''first baseline'' (''last baseline'').
 
 		<dt>Flex Items:
@@ -899,7 +899,7 @@ Baseline Content-Alignment</h3>
 		<dt>Grid Items:
 		<dd>
 			A <a>grid item</a> participates in first (last) <a>baseline content-alignment</a>
-			in its startmost (endmost) row or column (whichever matches its <a>inline axis</a>)
+			in its startmost (endmost) row or column (whichever is parallel to its <a>inline axis</a>)
 			if its computed 'align-content' is ''first baseline'' (''last baseline''),
 			and its computed 'align-self' or 'justify-self' (whichever affects its <a>block axis</a>)
 			is ''align-self/stretch'' or ''self-start'' (''self-end'').