[css-scroll-snap] Wording tweaks. Make it clear that automatic block/inline is chosen wrt the element's scroll container, not itself (that would be silly).

Author: fantasai

css-scroll-snap/Overview.bs

@@ -489,27 +489,28 @@ Scroll Snapping Alignment: the 'scroll-snap-align' property {#scroll-snap-align}
 	<dl>
 		<dt id=scroll-snap-align-none>none
 		<dd>
-			The element does not specify any <a>snap positions</a> at all,
+			Specifies that the box contributes no <a>snap positions</a> at all,
 			i.e. both axes compute to ''scroll-snap-align/none''.
 
 		<dt id=scroll-snap-align-single>[ block | inline ]? [ edges | <<snap-alignment>> ]
 		<dd>
-			The element declares a single <a>1D snap position</a>,
-			in either the <a>block</a> or <a>inline</a> axis,
-			as specified,
-			and the other axis computes to ''scroll-snap-align/none''.
+			Specifies a <a>1D snap position</a>
+			in either the <a>block</a> or <a>inline</a> axis.
 
-			If neither <css>block</css> nor <css>inline</css> is specified,
-			the axis is automatically chosen:
+			If a <dfn for=scroll-snap-align type=value>block</dfn> or <dfn for=scroll-snap-align type=value>inline</dfn> keyword is specified,
+			the specified alignment is for that axis,
+			and the other axis computes to ''scroll-snap-align/none''.
+			Otherwise,
+			the used axis is automatically chosen:
 
-			* If the element is only scrollable in one axis
+			* If the box’s nearest <a>scroll container</a> is only scrollable in one axis
 				(only one axis has its 'overflow' set to ''overflow/auto'' or ''overflow/scroll'')
 				the scrollable axis is chosen.
-			* Otherwise, the <a>block</a> axis is chosen.
+			* Otherwise, the nearest <a>scroll container</a>’s <a>block axis</a> is chosen.
 
 		<dt id=scroll-snap-align-double>[ none | edges | <<snap-alignment>> ]{2}
 		<dd>
-			The element declares two <a>1D snap positions</a>,
+			Specifies two <a>1D snap positions</a>,
 			one in each axis.
 			The first value is in the <a>inline</a> axis,
 			and the second is in the <a>block</a> axis.
@@ -519,10 +520,10 @@ Scroll Snapping Alignment: the 'scroll-snap-align' property {#scroll-snap-align}
 			The element declares a <a>2D snap position</a>.
 
 			If both alignments are given,
-			the first refers to the <a>inline</a> axis
-			and the second refers to the <a>block</a> axis.
+			the first applies to the <a>inline</a> axis
+			and the second applies to the <a>block</a> axis.
 			If only one is given,
-			the position refers to both axises.
+			the position applies to both axises.
 	</dl>
 
 	For all of these values,