Update css test for Safari to work in more cases

Author: dpvc

ts/output/chtml/Wrappers/TextNode.ts

@@ -63,14 +63,8 @@ CommonTextNodeMixin<CHTMLConstructor<any, any, any>>(CHTMLWrapper) {
     //  WebKit-specific CSS to handle bug with clipped characters.
     //  (test found at https://browserstrangeness.bitbucket.io/css_hacks.html#safari)
     //
-    '@supports (-webkit-marquee-repetition:infinite) and (object-fit:fill)': {
-      //
-      //  We don't really support nested CSS, so fake it byt putting the CSS
-      //    directly in the string, and commenting out the colon that is
-      //    inserted after the selector (that would normally be a CSS property name)
-      //    See issue #2435.
-      //
-      'mjx-c::before/*': '*/ {will-change: opacity}'
+    '_::-webkit-full-page-media, _:future, :root mjx-container': {
+      'will-change': 'opacity'
     }
   };