[css-align-3] Add safe to fallback of space-evenly and space-around. w3c#5088

Author: fantasai

css-align-3/Overview.bs

@@ -714,7 +714,7 @@ Distributed Alignment: the ''<content-distribution>/stretch'', ''space-between''
 				     alt="For example, given three items, all excess space is split into sixths and distributed: one sixth at the start, one at the end, and two sixths (one third) each between the first two and between the last two items.">
 			</figure>
 
-			The default [=fallback alignment=] for this value is ''center''.
+			The default [=fallback alignment=] for this value is ''safe center''.
 
 		<dt><dfn>space-evenly</dfn>
 		<dd>
@@ -730,7 +730,7 @@ Distributed Alignment: the ''<content-distribution>/stretch'', ''space-between''
 				     alt="For example, given three items, all excess space is split into fourths and distributed: to the start, to the end, to between the first two, and to between the last two items.">
 			</figure>
 
-			The default [=fallback alignment=] for this value is ''center''.
+			The default [=fallback alignment=] for this value is ''safe center''.
 
 		<dt><dfn>stretch</dfn>
 		<dd>
@@ -2397,6 +2397,8 @@ Changes</h2>
 	<ul>
 		<li>Allowed reordering of ''[ first | last ]'' and ''align-self/baseline'' components of <<baseline-position>>.
 		(<a href="https://github.com/w3c/csswg-drafts/issues/5235">Issue 5235</a>)
+		<li>Make [=fallback alignment=] of ''space-around'' and ''space-evenly'' include ''safe''.
+		(<a href="https://github.com/w3c/csswg-drafts/issues/5088">Issue 5088</a>)
 	</ul>
 
 	Changes since the <a href="https://www.w3.org/TR/2018/WD-css-align-3-20181206/">6 December 2018 Working Draft</a> include: