[css-multicol-2] Clarifying behavior of row sizes

Relates to #11976

Author: rachelandrew

css-multicol-2/Overview.bs

@@ -555,6 +555,8 @@ The multi-column model</h2>
 	the height of each column is defined by the 'column-height' property.
 	If there is more content than will fit in a single row a new multicol row is created
 	in the block direction, with columns of the size defined by the 'column-height' property.
+	If a row is only partially filled with content,
+	the size defined by 'column-height' is still maintained with empty space following the content.
 
 	When a <i>spanning element</i> divides the
 	multi-column container: a new multicol line is created.
@@ -568,9 +570,10 @@ The multi-column model</h2>
 			<figcaption>A demonstration of how the spanning element divides the multicol container.</figcaption>
 		</figure>
 	</div>
-
-	Issue(11976): This issue deals with the scenario where there is not enough space
-	in the current multicol row for a spanning element. Once resolved, add details here.  
+    
+    If the spanning element is larger in the block direction than the space available in the current multicol row,
+	the row geometry is maintained. The spanner is allowed to cross the row boundary,
+	over any gap, and into the next row.
 
 	A [=multi-column container=] therefore is a regular [=block container=]
 	that establishes a new [=independent formatting context=]
@@ -823,6 +826,13 @@ The number and size of columns</h2>
 	you may end up with some additional space.
 	The properties defined in the [[CSS-ALIGN]] specification detail how to deal with it.
 
+	When 'column-height' is not 'auto' the size in the block direction is not flexible.
+	If there is not enough content to fill a row of columns at the set size,
+	empty space is left.
+	
+	If a spanner is introduced that is taller than the set size,
+	the row geometry will be maintained, and the spanner will overflow into the next row, crossing any 'row-gap'.
+
 <h3 id='cc'>The Number of Columns: the 'column-count' property</h3>
 
 	<pre class=propdef>
@@ -1481,7 +1491,7 @@ Spanning columns</h2>
 		<dt><dfn>all</dfn></dt>
 		<dd>
 			The element forces a column break and is taken [=out of flow=]
-			to span across all columns of the nearest multicol ancestor
+			to span across all columns of the current multicol row
 			in the same [=block formatting context=].
 			Content in the normal flow that appears before the element
 			is automatically balanced across all columns
@@ -2288,6 +2298,12 @@ This appendix is <em>informative</em>.
 <h3 id="changes-from-multicol1">Changes from the <a href="https://www.w3.org/TR/2024/CR-css-multicol-1-20240516/">Candidate Recommendation (CR) of CSS-MULTICOL-1 of 16 May 2024</a></h3>
 
 <ul>
+    <li>Defines that the size of the columns in the block direction is maintained when 'column-height' is set, even if there's not enough content to fill a row.
+	<a href="https://github.com/w3c/csswg-drafts/issues/11976#issuecomment-3206088562">Resolved 20 August 2025</a></li>
+	<li>Defines that spanners only span the current row of columns when wrapping.
+	<a href="https://github.com/w3c/csswg-drafts/issues/11976#issuecomment-3206088562">Resolved 20 August 2025</a></li>
+    <li>Defines what happens when a spanner is larger than the available space in the block direction.
+	<a href="https://github.com/w3c/csswg-drafts/issues/11976#issuecomment-3206088562">Resolved 20 August 2025</a></li>
     <li>Updates the ''columns'' shorthand property to include ''column-height''. <a href="https://github.com/w3c/csswg-drafts/issues/12050#issuecomment-3160860557">Resolved 6 Aug 2025</a>.
 	<li>Adds a draft of proposed ''column-wrap'' property.</li>
 	<li>Adds the ''column-height'' property. <a href="https://github.com/w3c/csswg-drafts/issues/2923#issuecomment-2625930018">Resolved 30 Jan 2025</a>.