[css-view-transitions-2] Update Introduction for scoped transitions.

css-view-transitions-2/Overview.bs

@@ -115,7 +115,7 @@ spec:css2; type:dfn; text:viewport
 	This specification introduces a DOM API and associated CSS features
 	that allow developers to create animated visual transitions,
 	called <dfn export>view transitions</dfn>
-	between different states of a [=/document=],
+	between different states of a [=/document=] or an [=/element=],
 	or between distinct same-origin documents.
 
 ## Level 2 Updates ## {#intro-l2}
@@ -129,6 +129,7 @@ spec:css2; type:dfn; text:viewport
 			and more specifically based on the active view transition being of a certain type.
 		* [[#shared-style-with-vt-classes|Sharing styles between view transition pseudo-elements]], a way to declare a style once,
 			and use it for multiple view transition pseudo-elements. This includes the 'view-transition-class' property, and [[#pseudo-element-class-additions|additions to named pseudo-elements]]
+		* [[#scoped-vt|Scoped view transitions]], a way to perform view transitions within the scope of a DOM subtree.
 
 ## Separating Visual Transitions from DOM Updates ## {#separating-transitions}
 
@@ -155,10 +156,12 @@ spec:css2; type:dfn; text:viewport
 
 ## View Transition Customization ## {#customizing}
 
-	By default, <code>document.{{Document/startViewTransition()}}</code>
-	creates a [=view transition=] consisting of
-	a page-wide cross-fade between the two DOM states.
-	Developers can also choose which elements are captured independently
+	By default, <code>element.{{Element/startViewTransition()}}</code>
+	and <code>document.{{Document/startViewTransition()}}</code>
+	create a [=view transition=] consisting of a cross-fade of the entire
+	[=ViewTransition/root element=] between the two DOM states.
+
+	Developers can instead choose which descendant elements are captured independently
 	using the 'view-transition-name' CSS property,
 	allowing these to be animated independently of the rest of the page.
 	Since the transitional state (where both old and new visual captures exist)
@@ -171,12 +174,13 @@ spec:css2; type:dfn; text:viewport
 
 	A successful [=view transition=] goes through the following phases:
 
-	1. Developer calls <code>document.{{Document/startViewTransition}}({{ViewTransitionUpdateCallback|updateCallback}})</code>,
+	1. Developer calls <code>document.{{Document/startViewTransition}}({{ViewTransitionUpdateCallback|updateCallback}})</code>
+		or <code>element.{{Element/startViewTransition}}({{ViewTransitionUpdateCallback|updateCallback}})</code>,
 		which returns a {{ViewTransition}}, <var>viewTransition</var>.
 
 	1. Current state captured as the “old” state.
 
-	1. Rendering paused.
+	1. Rendering paused within the [=ViewTransition/root element=].
 
 	1. Developer's {{ViewTransitionUpdateCallback|updateCallback}} function, if provided, is called,
 		which updates the document state.