Updated syntax of @page to the latest spec.

css/at-rules.json

@@ -262,7 +262,7 @@
     "status": "standard"
   },
   "@page": {
-    "syntax": "@page <page-selector-list> {\n  <group-rule-body>\n}",
+    "syntax": "@page <page-selector-list> {\n  <page-body>\n},",
     "interfaces": [
       "CSSPageRule"
     ],

css/syntaxes.json

@@ -102,9 +102,15 @@
   "numeric-fraction-values": "[ diagonal-fractions | stacked-fractions ]",
   "numeric-spacing-values": "[ proportional-nums | tabular-nums ]",
   "opacity()": "opacity( [ <number-percentage> ] )",
+  "page-body": "<declaration>? [ ; <page-body> ]? | <page-margin-box> <page-body>",
+  "page-margin-box": "<page-margin-box-type> {\n  <declaration-list>\n}",
+  "page-margin-box-type": "@top-left-corner | @top-left | @top-center | @top-right | @top-right-corner | @bottom-left-corner | @bottom-left | @bottom-center | @bottom-right | @bottom-right-corner | @left-top | @left-middle | @left-bottom | @right-top | @right-middle | @right-bottom",
+  "page-selector-list": "[ <page-selector># ]?",
+  "page-selector": "<pseudo-page>+ | <ident> <pseudo-page>*",
   "perspective()": "perspective( <length> )",
   "polygon()": "polygon( <fill-rule>? , [ <length-percentage> <length-percentage> ]# )",
   "position": "[[ left | center | right | top | bottom | <length-percentage> ] | [ left | center | right | <length-percentage> ] [ top | center | bottom | <length-percentage> ] | [ center | [ left | right ] <length-percentage>? ] && [ center | [ top | bottom ] <length-percentage>? ]]",
+  "pseudo-page": ": [ left | right | first | blank ]",
   "radial-gradient()": "radial-gradient( [ <ending-shape> || <size> ]? [ at <position> ]? , <color-stop-list> )",
   "relative-size": "larger | smaller",
   "repeat-style": "repeat-x | repeat-y | [ repeat | space | round | no-repeat ]{1,2}",