Update mentions of 'scroll container' to refer to scrollable axises when appropriate. WIP w3c#12289

Author: tabatkins

css-align-3/Overview.bs

@@ -888,8 +888,8 @@ Automatic Overflow Alignment Safety</h4>
 <h5 id=auto-safety-scroll>
 Content Distribution for Scroll Containers</h5>
 
-	The default [=overflow alignment=] behavior
-	for [=content distribution=] on [=scroll containers=] is ''unsafe''.
+	In a [=scrollable axis=] of a [=scroll container=],
+	the default [=overflow alignment=] behavior for [=content distribution=] is ''unsafe''.
 	Non-''justify-content/normal'' values of the [=content-distribution properties=] instead
 	alter the [=scrollable overflow area=] in order to allow access to the overflowing content.
 	See [[#overflow-scroll-position]].
@@ -923,6 +923,7 @@ Self-Alignment for Absolutely Positioned Boxes</h5>
 		if the [=original containing block=] is generated by a [=scroll container=]
 		(and is not its [=fixed containing block=]),
 		the |overflow limit rect| is extended to infinity
+		in the [=scrollable axises=]
 		in any direction that does not extend into the [=unreachable scrollable overflow region=].
 	</div>
 
@@ -1028,7 +1029,7 @@ The 'justify-content' and 'align-content' Properties</h3>
 				If a <<content-distribution>> is specified
 				its <a>fallback alignment</a> is used instead.
 				If no <<overflow-position>> is specified,
-				and the [=block container=] is not a [=scroll container=],
+				and the [=block container=] is not a [=block-axis scroll container=],
 				then alignment is ''align-content/safe''.
 		<tr>
 			<th>'justify-content' Axis
@@ -1180,8 +1181,8 @@ Content-Distribution Shorthand: the 'place-content' property</h3>
 <h3 id="overflow-scroll-position">
 Alignment Overflow and Scroll Containers</h3>
 
-	When the <a>content-distribution properties</a> are set
-	on a <a>scroll container</a> with an overflowing <a>alignment subject</a>,
+	When the <a>content-distribution properties</a> are set in a [=scrollable axis=]
+	of a <a>scroll container</a> with an overflowing <a>alignment subject</a>,
 	they reduce the clipping of the [=unreachable scrollable overflow region=]
 	just enough to ensure that <a>alignment subject</a> can be scrolled
 	into its ''align-content/start''-aligned position.
@@ -2125,7 +2126,7 @@ Determining the Baselines of a Box</h3>
 			However, for legacy reasons
 			if its 'baseline-source' is ''baseline-source/auto'' (the [=initial value=])
 			a [=block-level=] or [=inline-level=] [=block container=]
-			that is a [=scroll container=]
+			that is a [=block-axis scroll container=]
 			always has a [=last baseline set=],
 			whose baselines all correspond to its [=block-end=] [=margin edge=].
 
@@ -2240,7 +2241,7 @@ Determining the Baselines of a Box</h3>
 			and ''vertical-rl'' if 'direction' is ''rtl''.
 
 	For the purposes of finding the baselines of a box,
-	it and all its [=in-flow=] descendants with a scrolling mechanism (see the 'overflow' property)
+	it and all its [=in-flow=] descendants that are [=block-axis scroll containers=]
 	must be considered as if scrolled to their initial scroll position.
 	Additionally,
 	if the position of a [=scroll container=]’s first/last baseline
@@ -2406,6 +2407,9 @@ Appendix A: Static Position Terminology</h2>
 Changes</h2>
 
 	Changes since the <a href="https://www.w3.org/TR/2025/WD-css-align-3-20250311/">11 March 2025 Working Draft</a> include:
+	* Ensure all [=scroll container=] interactions
+		properly pay attention to the [=scrollable axises=].
+		(<a href="https://github.com/w3c/csswg-drafts/issues/12289">Issue 12289</a>)
 	* Clarify that [[#auto-safety-position]] applies when 'position-area' alters the [=used value=] of ''align-self/normal''.
 	* Allow absolutely positioned boxes to honor alignment even when overflowing into
 		the scrollable overflow area of a scroll container containing block.

css-anchor-position-1/Overview.bs

@@ -1215,6 +1215,7 @@ specifically, the [=default anchor element=]:
 			[=used value|used=] [=inset properties=] in the axis
 			refers to a [=target anchor element=]
 			with the same nearest [=scroll container=] ancestor
+			with that axis as a [=scrollable axis=]
 			as |abspos|'s [=default anchor box=].
 
 	Note: If |abspos| has a [=position options list=],

css-backgrounds-4/Overview.bs

@@ -625,7 +625,7 @@ Affixing Images: the 'background-attachment' property</h3>
 		<dt><dfn>local</dfn></dt>
 			<dd>
 				The background is fixed with regard to the box's contents:
-				if the box has a scrolling mechanism,
+				if the box is a [=scroll container=],
 				the background scrolls with the box's contents,
 				and the [=background painting area=] and [=background positioning area=]
 				are relative to the [=scrollable overflow area=] of the box

css-flexbox-1/Overview.bs

@@ -1298,7 +1298,7 @@ Automatic Minimum Size of Flex Items</h3>
 	the used value of a <a>main axis</a> <a>automatic minimum size</a>
 	on a <a>flex item</a> whose [=computed value|computed=] 'overflow' value is [=non-scrollable overflow value|non-scrollable=]
 	is its [=content-based minimum size=];
-	for <a>scroll containers</a> the <a>automatic minimum size</a> is zero, as usual.
+	for [=block-axis scroll container|main-axis scroll containers=] the <a>automatic minimum size</a> is zero, as usual.
 
 	The <dfn>content-based minimum size</dfn> of a [=flex item=]
 	differs depending on whether the [=flex item=] is [=replaced element|replaced=] or not:
@@ -4600,7 +4600,7 @@ Flex Container Intrinsic Cross Sizes</h4>
 		is smaller than the [=max-content size=].
 		If the flex container has a height constraint,
 		this will result in overflow,
-		but if the [=flex container=] is also a [=scroll container=],
+		but if the [=flex container=] is also a [=block-axis scroll container|main-axis scroll container=],
 		it will at least be large enough to fit
 		any given column entirely within its [=scrollport=].
 
@@ -5266,6 +5266,10 @@ Changes since the <a href="https://www.w3.org/TR/2025/CRD-css-flexbox-1-20251014
 </h3>
 
 	<ul>
+		<li id="change-2025-scroll-axis">
+			When appropriate, mention [=scrollable axises=].
+			(<a href="https://github.com/w3c/csswg-drafts/issues/12289">Issue 12289</a>)
+
 		<li id="change-2025-web-compat-intrinsic">
 			Defined the web-compatible intrinsic sizing algo in [[#intrinsic-main-sizes-compat]].
 			(<a href="https://github.com/w3c/csswg-drafts/issues/8884#issuecomment-1636311498">Issue 8884</a>)