[css-grid-3] Clarify that baseline self-alignment in the stacking axis falls back to the fallback value. #10275

Author: tabatkins

css-grid-3/Overview.bs

@@ -1188,13 +1188,14 @@ Baseline Alignment</h3>
 	the same as for a regular [=grid container=] in that axis.
 
 	[=Baseline alignment=] is not supported in the [=stacking axis=].
+	The [=baseline alignment=] values of the [=self-alignment properties=]
+	on [=grid items=] are treated as their [=fallback alignment=] in this axis.
 	The first baseline set of the [=grid container=] in this axis
 	is generated from the highest [=alignment baseline=]
 	among the [=grid items=] placed first in each track,
 	and the last baseline set from the lowest [=alignment baseline=]
 	among the [=grid items=] placed last in each track.
 
-	ISSUE: We could support baseline alignment in the first row. Do we want to?
 
 <h2 id="pagination">
 Fragmentation</h2>
@@ -1345,6 +1346,10 @@ Recent Changes</h3>
 		(<a href="https://github.com/w3c/csswg-drafts/issues/11480">Issue 11480</a>)
 	* Simplified the sizing calcs for automatic-positioned [=subgrids=] in a [=grid lanes container=].
 		(<a href="https://github.com/w3c/csswg-drafts/issues/10926">Issue 10926</a>)
+	* Clarify that baseline values for [=self-alignment properties=] in the stacking axis
+		fall back to their fallback value.
+		(<a href="https://github.com/w3c/csswg-drafts/issues/10275">Issue 10275</a>)
+
 
 	The following changes have been made since the
 	<a href="https://www.w3.org/TR/2025/WD-css-grid-3-20251223/">23 December 2025 Working Draft</a>: