[cssom] (editorial) Clarify what is intended to be author-level

Author: Simon Pieters

cssom/idl/Window.idl

@@ -63,8 +63,9 @@ partial interface Window {
        <span>CSS declaration block declarations</span> set to all properties\
        the user agent supports with as value the computed value\
        for <var>obj</var> using the user agent-level style rules and user-level style\
-       rules associated with <var>doc</var>, ignoring author-level style rules,\
-       transitions, animations, override-level style rules and presentational hints.</p>\
+       rules associated with <var>doc</var>, ignoring transitions, animations,\
+       author-level style rules, author-level presentational hints and override-level\
+       style rules.</p>\
       </li>\
     </ol>"
   ]