[css-anchor-position-1] Put the element's base styles in as the first item of the 'position options list'. #12890

Author: tabatkins

css-anchor-position-1/Overview.bs

@@ -1511,7 +1511,8 @@ This property provides a list of alternate positioning styles
 to try when the [=absolutely positioned box=]
 overflows its [=inset-modified containing block=].
 This <dfn export>position options list</dfn>
-is initially empty.
+initially contains a single [=position option=]
+generated from the element's base styles.
 
 Each comma-separated entry in the list is a separate option:
 either the name of a ''@position-try'' block,
@@ -1989,7 +1990,7 @@ Applying Position Fallback {#fallback-apply}
 When a positioned box
 (shifted by its [=default scroll shift=])
 overflows its [=inset-modified containing block=],
-and has a non-empty [=position options list=],
+and has more than one [=position option=] in its [=position options list=],
 it [=determines position fallback styles=]
 to attempt to find an option that avoids overflow.