[css-scroll-snap] Miscellaneous minor fixes

Author: fantasai

css-scroll-snap/Overview.bs

@@ -204,8 +204,8 @@ Scroll Snapping Model {#snap-model}
 	<a>scroll container</a>
 	on the element's <a>containing block chain</a>.
 
-Scroll Snapping Container {#snap-container}
-=========================
+Capturing Scroll Snap Areas: Properties on the scroll container {#snap-container}
+===========================
 
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@@ -408,15 +408,15 @@ Scroll Snapping Window: the 'scroll-snap-padding' property {#snap-padding}
 	Initial: 0
 	Applies to: <a>scroll containers</a>
 	Inherited: no
-	Percentages: relative to the corresponding axis of the <a>scroll container</a>’s visual viewport
+	Percentages: relative to the corresponding dimension of the <a>scroll container</a>’s visual viewport
 	Computed value: as specified, with lengths made absolute
-	Animatable: yes
+	Animatable: as length, percentage, or calc
 	Media: interactive
 	</pre>
 
 	The 'scroll-snap-padding' property defines the <dfn local-lt="snap window">scroll snap window</dfn>--
-	the area of the viewport that is used as the <a>alignment container</a>
-	when aligning a <a>scroll snap area</a> to its <a>snap position</a>.
+	the area of the visual viewport that is used as the <a>alignment container</a>
+	for the <a>scroll snap areas</a> when calculating <a>snap positions</a>.
 	Values are interpreted as for 'padding',
 	and specify inward offsets from each edge of the visual viewport.
 
@@ -446,8 +446,8 @@ Scroll Snapping Window: the 'scroll-snap-padding' property {#snap-padding}
 	all of the <a href="#longhands"><css>scroll-snap-padding-*</css> longhands</a>
 	in one declaration.
 
-Element-based Snapping {#element}
-======================
+Defining Scroll Snap Positions: Properties on the scrolling content {#element}
+==============================
 
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@@ -469,17 +469,18 @@ Scroll Snapping Margin: the 'scroll-snap-margin' property {#scroll-snap-areas}
 	Applies to: all elements
 	Inherited: no
 	Computed value: as specified, with lengths made absolute
-	Animatable: see individual properties
+	Animatable: as length
 	Media: interactive
 	</pre>
 
-	Specifies the <dfn lt="scroll snap area" local-lt="snap area">scroll snap area</dfn>
+	The 'scroll-snap-margin' property defines
+	the <dfn lt="scroll snap area" local-lt="snap area">scroll snap area</dfn>
 	that is used for snapping this box to the viewport.
 	The <<length>> values give outsets
-	(similar to 'margin' or 'border-image-outset').
-	The <a>scroll snap area</a> is the bounding box of the transformed border box,
+	(interpreted as for 'margin' or 'border-image-outset').
+	The <a>scroll snap area</a> is the rectangular bounding box of the transformed border box,
 	plus the specified outsets,
-	in the <a>scroll container’s</a> coordinate space.
+	axis-aligned in the <a>scroll container’s</a> coordinate space.
 
 	Note: This ensures that the <a>scroll snap area</a> is always rectangular and axis-aligned
 	to the <a>scroll container’s</a> coordinate space.
@@ -513,10 +514,11 @@ Scroll Snapping Alignment: the 'scroll-snap-align' property {#scroll-snap-alignm
 	Media: interactive
 	</pre>
 
-	Specifies the element's <a>snap position</a> as an alignment of
+	The 'scroll-snap-align' property specifies
+	the box's <a>snap position</a> as an alignment of
 	its <a>snap area</a> (as the <a>alignment subject</a>)
 	within its <a>snap container's</a> <a>snap window</a> (as the <a>alignment container</a>).
-	The two values specify the snapping behavior in the <a>inline axis</a> and <a>block axis</a>,
+	The two values specify alignment in the <a>inline axis</a> and <a>block axis</a>,
 	respectively.
 	If only one value is specified,
 	the second value defaults to the same value.
@@ -546,7 +548,7 @@ Scroll Snapping Alignment: the 'scroll-snap-align' property {#scroll-snap-alignm
 		</pre>
 	</div>
 
-	The <dfn export>scroll alignment values</dfn> are defined as follows:
+	Values are defined as follows:
 
 	<dl dfn-type=value dfn-for="scroll-snap-align">
 		<dt><dfn>none</dfn>
@@ -557,19 +559,22 @@ Scroll Snapping Alignment: the 'scroll-snap-align' property {#scroll-snap-alignm
 		<dd>
 			Start alignment of this box's <a>scroll snap area</a>
 			within the <a>scroll container</a>'s <a>snap window</a>
-			is a valid <a>snap position</a>.
+			is a valid <a>snap position</a>
+			in the specified axis.
 
 		<dt><dfn>end</dfn>
 		<dd>
 			End alignment of this box's <a>scroll snap area</a>
 			within the <a>scroll container</a>'s <a>snap window</a>
-			is a valid <a>snap position</a>.
+			is a valid <a>snap position</a>
+			in the specified axis.
 
 		<dt><dfn>center</dfn>
 		<dd>
 			Center alignment of this box's <a>scroll snap area</a>
 			within the <a>scroll container</a>'s <a>snap window</a>
-			is a valid <a>snap position</a>.
+			is a valid <a>snap position</a>
+			in the specified axis.
 	</dl>
 
 	If the element's <a>scroll container</a> is <a>point-snapping</a>,
@@ -1046,8 +1051,9 @@ Physical Longhands for 'scroll-snap-padding' {#padding-longhands-physical}
 	Name: scroll-snap-padding-top, scroll-snap-padding-right, scroll-snap-padding-bottom, scroll-snap-padding-left
 	Value: <<length>> | <<percentage>>
 	Initial: 0
-	Applies to: all elements
+	Applies to: <a>scroll containers</a>
 	Inherited: no
+	Percentage: relative to the corresponding dimension of the <a>scroll container</a>’s visual viewport
 	Computed value: as specified, with lengths made absolute
 	Animatable: as length, percentage, or calc
 	Media: interactive
@@ -1065,8 +1071,9 @@ Flow-relative Longhands for 'scroll-snap-padding'  {#padding-longhands-logical}
 	Name: scroll-snap-padding-inline-start, scroll-snap-padding-block-start, scroll-snap-padding-inline-end, scroll-padding-block-end
 	Value: <<length>> | <<percentage>>
 	Initial: 0
-	Applies to: all elements
+	Applies to: <a>scroll containers</a>
 	Inherited: no
+	Percentages: relative to the corresponding dimension of the <a>scroll container</a>’s visual viewport
 	Computed value: as specified, with lengths made absolute
 	Animatable: as length, percentage, or calc
 	Media: interactive
@@ -1083,6 +1090,7 @@ Flow-relative Longhands for 'scroll-snap-padding'  {#padding-longhands-logical}
 	Initial: 0
 	Applies to: all elements
 	Inherited: no
+	Percentages: relative to the corresponding dimension of the <a>scroll container</a>’s visual viewport
 	Computed value: as specified, with lengths made absolute
 	Animatable: as length, percentage, or calc
 	Media: interactive
@@ -1162,3 +1170,18 @@ This specification does not expose any information whatsoever
 that is not already exposed to the DOM directly;
 it just makes scrolling slightly more functional.
 There are no new privacy or security considerations.
+
+Acknowledgements {#acknowledgements}
+================
+
+	Many thanks to
+	David Baron,
+	Simon Fraser,
+	Håkon Wium Lie,
+	Edward O'Connor,
+	François Remy,
+	Majid Valpour,
+	potentially some anonymous Microsoft engineers (?),
+	and most especially Robert O'Callahan
+	for their proposals and recommendations,
+	which have been incorporated into this document.