LibWeb/CSS: Add basic implementation of CSSMarginRule

This is a bit under-specced, specifically there's no definition of
CSSMarginDescriptors so I've gone with CSSStyleProperties for now. Gets
us 17 WPT subtests.

Libraries/LibWeb/CMakeLists.txt

@@ -80,6 +80,7 @@ set(SOURCES
     CSS/CSSKeyframesRule.cpp
     CSS/CSSLayerBlockRule.cpp
     CSS/CSSLayerStatementRule.cpp
+    CSS/CSSMarginRule.cpp
     CSS/CSSMediaRule.cpp
     CSS/CSSNamespaceRule.cpp
     CSS/CSSNestedDeclarations.cpp

Libraries/LibWeb/CSS/CSSMarginRule.cpp

@@ -0,0 +1,77 @@
+/*
+ * Copyright (c) 2025, Sam Atkins <sam@ladybird.org>
+ *
+ * SPDX-License-Identifier: BSD-2-Clause
+ */
+
+#include <LibWeb/Bindings/CSSMarginRulePrototype.h>
+#include <LibWeb/Bindings/Intrinsics.h>
+#include <LibWeb/CSS/CSSMarginRule.h>
+#include <LibWeb/CSS/CSSStyleProperties.h>
+#include <LibWeb/WebIDL/ExceptionOr.h>
+
+namespace Web::CSS {
+
+GC_DEFINE_ALLOCATOR(CSSMarginRule);
+
+GC::Ref<CSSMarginRule> CSSMarginRule::create(JS::Realm& realm, FlyString name, GC::Ref<CSSStyleProperties> style)
+{
+    return realm.create<CSSMarginRule>(realm, move(name), style);
+}
+
+CSSMarginRule::CSSMarginRule(JS::Realm& realm, FlyString name, GC::Ref<CSSStyleProperties> style)
+    : CSSRule(realm, Type::Margin)
+    , m_name(name.to_ascii_lowercase())
+    , m_style(style)
+{
+    m_style->set_parent_rule(*this);
+}
+
+void CSSMarginRule::initialize(JS::Realm& realm)
+{
+    WEB_SET_PROTOTYPE_FOR_INTERFACE(CSSMarginRule);
+    Base::initialize(realm);
+}
+
+String CSSMarginRule::serialized() const
+{
+    // AD-HOC: There is currently no spec for serializing CSSMarginRule.
+    StringBuilder builder;
+    builder.appendff("@{} {{ ", m_name);
+    if (m_style->length() > 0) {
+        builder.append(m_style->serialized());
+        builder.append(' ');
+    }
+    builder.append('}');
+
+    return builder.to_string_without_validation();
+}
+
+void CSSMarginRule::visit_edges(Visitor& visitor)
+{
+    Base::visit_edges(visitor);
+    visitor.visit(m_style);
+}
+
+// https://drafts.csswg.org/css-page-3/#syntax-page-selector
+bool is_margin_rule_name(StringView name)
+{
+    return name.equals_ignoring_ascii_case("top-left-corner"sv)
+        || name.equals_ignoring_ascii_case("top-left"sv)
+        || name.equals_ignoring_ascii_case("top-center"sv)
+        || name.equals_ignoring_ascii_case("top-right"sv)
+        || name.equals_ignoring_ascii_case("top-right-corner"sv)
+        || name.equals_ignoring_ascii_case("bottom-left-corner"sv)
+        || name.equals_ignoring_ascii_case("bottom-left"sv)
+        || name.equals_ignoring_ascii_case("bottom-center"sv)
+        || name.equals_ignoring_ascii_case("bottom-right"sv)
+        || name.equals_ignoring_ascii_case("bottom-right-corner"sv)
+        || name.equals_ignoring_ascii_case("left-top"sv)
+        || name.equals_ignoring_ascii_case("left-middle"sv)
+        || name.equals_ignoring_ascii_case("left-bottom"sv)
+        || name.equals_ignoring_ascii_case("right-top"sv)
+        || name.equals_ignoring_ascii_case("right-middle"sv)
+        || name.equals_ignoring_ascii_case("right-bottom"sv);
+}
+
+}

Libraries/LibWeb/CSS/CSSMarginRule.h

@@ -0,0 +1,40 @@
+/*
+ * Copyright (c) 2025, Sam Atkins <sam@ladybird.org>
+ *
+ * SPDX-License-Identifier: BSD-2-Clause
+ */
+
+#pragma once
+
+#include <LibWeb/CSS/CSSRule.h>
+
+namespace Web::CSS {
+
+// https://drafts.csswg.org/cssom/#cssmarginrule
+class CSSMarginRule final : public CSSRule {
+    WEB_PLATFORM_OBJECT(CSSMarginRule, CSSRule);
+    GC_DECLARE_ALLOCATOR(CSSMarginRule);
+
+public:
+    [[nodiscard]] static GC::Ref<CSSMarginRule> create(JS::Realm&, FlyString name, GC::Ref<CSSStyleProperties>);
+
+    virtual ~CSSMarginRule() override = default;
+
+    String name() const { return m_name.to_string(); }
+    GC::Ref<CSSStyleProperties> style() { return m_style; }
+    GC::Ref<CSSStyleProperties const> style() const { return m_style; }
+
+private:
+    CSSMarginRule(JS::Realm&, FlyString name, GC::Ref<CSSStyleProperties>);
+
+    virtual void initialize(JS::Realm&) override;
+    virtual String serialized() const override;
+    virtual void visit_edges(Visitor&) override;
+
+    FlyString m_name;
+    GC::Ref<CSSStyleProperties> m_style;
+};
+
+bool is_margin_rule_name(StringView);
+
+}

Libraries/LibWeb/CSS/CSSMarginRule.idl

@@ -0,0 +1,10 @@
+#import <CSS/CSSRule.idl>
+#import <CSS/CSSStyleProperties.idl>
+
+// https://drafts.csswg.org/cssom/#cssmarginrule
+[Exposed=Window]
+interface CSSMarginRule : CSSRule {
+    readonly attribute CSSOMString name;
+    // FIXME: This should be CSSMarginDescriptors, but that has no spec. https://github.com/w3c/csswg-drafts/issues/10106
+    [SameObject, PutForwards=cssText] readonly attribute CSSStyleProperties style;
+};

Libraries/LibWeb/CSS/CSSPageRule.cpp

@@ -104,7 +104,7 @@ String CSSPageRule::serialized() const
 
     StringBuilder builder;
 
-    // AD-HOC: There's no spec for this yet.
+    // AD-HOC: There's no spec for this yet, but Chrome puts declarations before margin rules.
     builder.append("@page "sv);
     if (auto selector = selector_text(); !selector.is_empty())
         builder.appendff("{} ", selector);
@@ -113,6 +113,15 @@ String CSSPageRule::serialized() const
         builder.append(descriptors.serialized());
         builder.append(' ');
     }
+    for (size_t i = 0; i < css_rules().length(); i++) {
+        auto rule = css_rules().item(i);
+        auto result = rule->css_text();
+
+        if (result.is_empty())
+            continue;
+
+        builder.appendff("{} ", result);
+    }
     builder.append("}"sv);
 
     return builder.to_string_without_validation();

Libraries/LibWeb/CSS/CSSRule.cpp

@@ -95,6 +95,7 @@ FlyString const& CSSRule::parent_layer_internal_qualified_name_slow_case() const
         case Type::NestedDeclarations:
         case Type::Property:
         case Type::Page:
+        case Type::Margin:
             break;
         }
     }

Libraries/LibWeb/CSS/CSSRule.h

@@ -31,6 +31,7 @@ public:
         Page = 6,
         Keyframes = 7,
         Keyframe = 8,
+        Margin = 9,
         Namespace = 10,
         Supports = 12,
         // AD-HOC: These are not included in the spec, but we need them internally. So, their numbers are arbitrary.

Libraries/LibWeb/CSS/CSSRuleList.cpp

@@ -152,6 +152,7 @@ void CSSRuleList::for_each_effective_rule(TraversalOrder order, Function<void(We
 
         case CSSRule::Type::LayerBlock:
         case CSSRule::Type::Media:
+        case CSSRule::Type::Page:
         case CSSRule::Type::Style:
         case CSSRule::Type::Supports:
             static_cast<CSSGroupingRule const&>(*rule).for_each_effective_rule(order, callback);
@@ -161,10 +162,10 @@ void CSSRuleList::for_each_effective_rule(TraversalOrder order, Function<void(We
         case CSSRule::Type::Keyframe:
         case CSSRule::Type::Keyframes:
         case CSSRule::Type::LayerStatement:
+        case CSSRule::Type::Margin:
         case CSSRule::Type::Namespace:
         case CSSRule::Type::NestedDeclarations:
         case CSSRule::Type::Property:
-        case CSSRule::Type::Page:
             break;
         }
 
@@ -217,6 +218,7 @@ bool CSSRuleList::evaluate_media_queries(HTML::Window const& window)
         case CSSRule::Type::Keyframe:
         case CSSRule::Type::Keyframes:
         case CSSRule::Type::LayerStatement:
+        case CSSRule::Type::Margin:
         case CSSRule::Type::Namespace:
         case CSSRule::Type::NestedDeclarations:
         case CSSRule::Type::Property:

Libraries/LibWeb/CSS/Parser/Parser.cpp

@@ -14,6 +14,7 @@
 
 #include <AK/Debug.h>
 #include <LibURL/Parser.h>
+#include <LibWeb/CSS/CSSMarginRule.h>
 #include <LibWeb/CSS/CSSStyleDeclaration.h>
 #include <LibWeb/CSS/CSSStyleProperties.h>
 #include <LibWeb/CSS/CSSStyleSheet.h>
@@ -1438,7 +1439,8 @@ bool Parser::is_valid_in_the_current_context(Declaration const&) const
     case RuleContext::AtFontFace:
     case RuleContext::AtPage:
     case RuleContext::AtProperty:
-        // @font-face, @page, and @property have descriptor declarations
+    case RuleContext::Margin:
+        // These have descriptor declarations
         return true;
 
     case RuleContext::AtKeyframes:
@@ -1455,9 +1457,9 @@ bool Parser::is_valid_in_the_current_context(Declaration const&) const
 
 bool Parser::is_valid_in_the_current_context(AtRule const& at_rule) const
 {
-    // All at-rules can appear at the top level
+    // All at-rules can appear at the top level, except margin rules
     if (m_rule_context.is_empty())
-        return true;
+        return !is_margin_rule_name(at_rule.name);
 
     // Only grouping rules can be nested within style rules
     if (m_rule_context.contains_slow(RuleContext::Style))
@@ -1482,13 +1484,16 @@ bool Parser::is_valid_in_the_current_context(AtRule const& at_rule) const
         // @supports cannot check for at-rules
         return false;
 
+    case RuleContext::AtPage:
+        // @page rules can contain margin rules
+        return is_margin_rule_name(at_rule.name);
+
     case RuleContext::AtFontFace:
     case RuleContext::AtKeyframes:
     case RuleContext::Keyframe:
-    case RuleContext::AtPage:
     case RuleContext::AtProperty:
+    case RuleContext::Margin:
         // These can't contain any at-rules
-        // FIXME: Eventually @page can contain margin-box at-rules: https://drafts.csswg.org/css-page-3/#margin-at-rules
         return false;
     }
 
@@ -1530,6 +1535,7 @@ bool Parser::is_valid_in_the_current_context(QualifiedRule const&) const
     case RuleContext::AtPage:
     case RuleContext::AtProperty:
     case RuleContext::Keyframe:
+    case RuleContext::Margin:
         // These can't contain qualified rules
         return false;
     }

Libraries/LibWeb/CSS/Parser/Parser.h

@@ -243,6 +243,7 @@ private:
     GC::Ptr<CSSKeyframesRule> convert_to_keyframes_rule(AtRule const&);
     GC::Ptr<CSSImportRule> convert_to_import_rule(AtRule const&);
     GC::Ptr<CSSRule> convert_to_layer_rule(AtRule const&, Nested);
+    GC::Ptr<CSSMarginRule> convert_to_margin_rule(AtRule const&);
     GC::Ptr<CSSMediaRule> convert_to_media_rule(AtRule const&, Nested);
     GC::Ptr<CSSNamespaceRule> convert_to_namespace_rule(AtRule const&);
     GC::Ptr<CSSPageRule> convert_to_page_rule(AtRule const& rule);

Libraries/LibWeb/CSS/Parser/RuleContext.cpp

@@ -4,6 +4,7 @@
  * SPDX-License-Identifier: BSD-2-Clause
  */
 
+#include <LibWeb/CSS/CSSMarginRule.h>
 #include <LibWeb/CSS/Parser/RuleContext.h>
 
 namespace Web::CSS::Parser {
@@ -25,6 +26,8 @@ RuleContext rule_context_type_for_rule(CSSRule::Type rule_type)
         return RuleContext::AtSupports;
     case CSSRule::Type::LayerBlock:
         return RuleContext::AtLayer;
+    case CSSRule::Type::Margin:
+        return RuleContext::Margin;
     case CSSRule::Type::NestedDeclarations:
         return RuleContext::Style;
     case CSSRule::Type::Page:
@@ -56,6 +59,8 @@ RuleContext rule_context_type_for_at_rule(FlyString const& name)
         return RuleContext::AtProperty;
     if (name.equals_ignoring_ascii_case("page"sv))
         return RuleContext::AtPage;
+    if (is_margin_rule_name(name))
+        return RuleContext::Margin;
     return RuleContext::Unknown;
 }
 

Libraries/LibWeb/CSS/Parser/RuleContext.h

@@ -23,6 +23,7 @@ enum class RuleContext : u8 {
     AtLayer,
     AtProperty,
     AtPage,
+    Margin,
 };
 RuleContext rule_context_type_for_rule(CSSRule::Type);
 RuleContext rule_context_type_for_at_rule(FlyString const&);

Libraries/LibWeb/CSS/Parser/RuleParsing.cpp

@@ -18,6 +18,7 @@
 #include <LibWeb/CSS/CSSKeyframesRule.h>
 #include <LibWeb/CSS/CSSLayerBlockRule.h>
 #include <LibWeb/CSS/CSSLayerStatementRule.h>
+#include <LibWeb/CSS/CSSMarginRule.h>
 #include <LibWeb/CSS/CSSMediaRule.h>
 #include <LibWeb/CSS/CSSNamespaceRule.h>
 #include <LibWeb/CSS/CSSNestedDeclarations.h>
@@ -102,6 +103,9 @@ GC::Ptr<CSSRule> Parser::convert_to_rule(Rule const& rule, Nested nested)
             if (at_rule.name.equals_ignoring_ascii_case("layer"sv))
                 return convert_to_layer_rule(at_rule, nested);
 
+            if (is_margin_rule_name(at_rule.name))
+                return convert_to_margin_rule(at_rule);
+
             if (at_rule.name.equals_ignoring_ascii_case("media"sv))
                 return convert_to_media_rule(at_rule, nested);
 
@@ -697,20 +701,25 @@ static Optional<PageSelectorList> parse_page_selector_list(Vector<ComponentValue
     return selector_list;
 }
 
-GC::Ptr<CSSPageRule> Parser::convert_to_page_rule(AtRule const& rule)
+GC::Ptr<CSSPageRule> Parser::convert_to_page_rule(AtRule const& page_rule)
 {
     // https://drafts.csswg.org/css-page-3/#syntax-page-selector
     // @page = @page <page-selector-list>? { <declaration-rule-list> }
-    auto page_selectors = parse_page_selector_list(rule.prelude);
+    auto page_selectors = parse_page_selector_list(page_rule.prelude);
     if (!page_selectors.has_value())
         return nullptr;
 
     GC::RootVector<GC::Ref<CSSRule>> child_rules { realm().heap() };
     DescriptorList descriptors { AtRuleID::Page };
-    rule.for_each_as_declaration_rule_list(
+    page_rule.for_each_as_declaration_rule_list(
         [&](auto& at_rule) {
-            // FIXME: Parse margin rules here.
+            if (auto converted_rule = convert_to_rule(at_rule, Nested::No)) {
-            (void)at_rule;
+                if (is<CSSMarginRule>(*converted_rule)) {
+                    child_rules.append(*converted_rule);
+                } else {
+                    dbgln_if(CSS_PARSER_DEBUG, "CSSParser: nested {} is not allowed inside @page rule; discarding.", converted_rule->class_name());
+                }
+            }
         },
         [&](auto& declaration) {
             if (auto descriptor = convert_to_descriptor(AtRuleID::Page, declaration); descriptor.has_value()) {
@@ -722,4 +731,21 @@ GC::Ptr<CSSPageRule> Parser::convert_to_page_rule(AtRule const& rule)
     return CSSPageRule::create(realm(), page_selectors.release_value(), CSSPageDescriptors::create(realm(), descriptors.release_descriptors()), rule_list);
 }
 
+GC::Ptr<CSSMarginRule> Parser::convert_to_margin_rule(AtRule const& rule)
+{
+    // https://drafts.csswg.org/css-page-3/#syntax-page-selector
+    // There are lots of these, but they're all in the format:
+    // @foo = @foo { <declaration-list> };
+
+    // FIXME: The declaration list should be a CSSMarginDescriptors, but that has no spec definition:
+    //        https://github.com/w3c/csswg-drafts/issues/10106
+    //        So, we just parse a CSSStyleProperties instead for now.
+    PropertiesAndCustomProperties properties;
+    rule.for_each_as_declaration_list([&](auto const& declaration) {
+        extract_property(declaration, properties);
+    });
+    auto style = CSSStyleProperties::create(realm(), move(properties.properties), move(properties.custom_properties));
+    return CSSMarginRule::create(realm(), rule.name, style);
+}
+
 }

Libraries/LibWeb/CSS/StyleComputer.cpp

@@ -3025,6 +3025,7 @@ void StyleComputer::build_qualified_layer_names_cache()
             case CSSRule::Type::FontFace:
             case CSSRule::Type::Keyframes:
             case CSSRule::Type::Keyframe:
+            case CSSRule::Type::Margin:
             case CSSRule::Type::Namespace:
             case CSSRule::Type::NestedDeclarations:
             case CSSRule::Type::Page:

Libraries/LibWeb/Dump.cpp

@@ -16,6 +16,7 @@
 #include <LibWeb/CSS/CSSKeyframesRule.h>
 #include <LibWeb/CSS/CSSLayerBlockRule.h>
 #include <LibWeb/CSS/CSSLayerStatementRule.h>
+#include <LibWeb/CSS/CSSMarginRule.h>
 #include <LibWeb/CSS/CSSMediaRule.h>
 #include <LibWeb/CSS/CSSNamespaceRule.h>
 #include <LibWeb/CSS/CSSNestedDeclarations.h>
@@ -687,6 +688,9 @@ void dump_rule(StringBuilder& builder, CSS::CSSRule const& rule, int indent_leve
     case CSS::CSSRule::Type::LayerStatement:
         dump_layer_statement_rule(builder, as<CSS::CSSLayerStatementRule const>(rule), indent_levels);
         break;
+    case CSS::CSSRule::Type::Margin:
+        dump_margin_rule(builder, as<CSS::CSSMarginRule const>(rule), indent_levels);
+        break;
     case CSS::CSSRule::Type::Media:
         dump_media_rule(builder, as<CSS::CSSMediaRule const>(rule), indent_levels);
         break;
@@ -774,6 +778,18 @@ void dump_page_rule(StringBuilder& builder, CSS::CSSPageRule const& page, int in
     indent(builder, indent_levels + 1);
     builder.appendff("selector: {}\n", page.selector_text());
     dump_descriptors(builder, page.descriptors(), indent_levels + 1);
+
+    indent(builder, indent_levels + 1);
+    builder.appendff("  Rules ({}):\n", page.css_rules().length());
+    for (auto& rule : page.css_rules())
+        dump_rule(builder, rule, indent_levels + 2);
+}
+
+void dump_margin_rule(StringBuilder& builder, CSS::CSSMarginRule const& margin, int indent_levels)
+{
+    indent(builder, indent_levels + 1);
+    builder.appendff("name: {}\n", margin.name());
+    dump_style_properties(builder, margin.style(), indent_levels + 1);
 }
 
 void dump_supports_rule(StringBuilder& builder, CSS::CSSSupportsRule const& supports, int indent_levels)

Libraries/LibWeb/Dump.h

@@ -31,6 +31,7 @@ void dump_keyframe_rule(StringBuilder&, CSS::CSSKeyframeRule const&, int indent_
 void dump_keyframes_rule(StringBuilder&, CSS::CSSKeyframesRule const&, int indent_levels = 0);
 void dump_media_rule(StringBuilder&, CSS::CSSMediaRule const&, int indent_levels = 0);
 void dump_page_rule(StringBuilder&, CSS::CSSPageRule const&, int indent_levels = 0);
+void dump_margin_rule(StringBuilder&, CSS::CSSMarginRule const&, int indent_levels = 0);
 void dump_style_rule(StringBuilder&, CSS::CSSStyleRule const&, int indent_levels = 0);
 void dump_supports_rule(StringBuilder&, CSS::CSSSupportsRule const&, int indent_levels = 0);
 void dump_property_rule(StringBuilder&, CSS::CSSPropertyRule const&, int indent_levels = 0);

Libraries/LibWeb/Forward.h

@@ -200,6 +200,7 @@ class CSSKeyframesRule;
 class CSSKeywordValue;
 class CSSLayerBlockRule;
 class CSSLayerStatementRule;
+class CSSMarginRule;
 class CSSMediaRule;
 class CSSNamespaceRule;
 class CSSNestedDeclarations;

Libraries/LibWeb/idl_files.cmake

@@ -31,6 +31,7 @@ libweb_js_bindings(CSS/CSSKeyframeRule)
 libweb_js_bindings(CSS/CSSKeyframesRule)
 libweb_js_bindings(CSS/CSSLayerBlockRule)
 libweb_js_bindings(CSS/CSSLayerStatementRule)
+libweb_js_bindings(CSS/CSSMarginRule)
 libweb_js_bindings(CSS/CSSMediaRule)
 libweb_js_bindings(CSS/CSS NAMESPACE)
 libweb_js_bindings(CSS/CSSNamespaceRule)

Tests/LibWeb/Text/expected/all-window-properties.txt

@@ -46,6 +46,7 @@ CSSKeyframeRule
 CSSKeyframesRule
 CSSLayerBlockRule
 CSSLayerStatementRule
+CSSMarginRule
 CSSMediaRule
 CSSNamespaceRule
 CSSNestedDeclarations

Tests/LibWeb/Text/expected/wpt-import/css/css-page/parsing/margin-rules-001.txt

@@ -2,8 +2,7 @@ Harness status: OK
 
 Found 33 tests
 
-17 Pass
+33 Pass
-16 Fail
 Pass	margin-rules-001
 Pass	@top-left-corner{ } should be an invalid rule
 Pass	@top-left{ } should be an invalid rule
@@ -21,19 +20,19 @@ Pass	@left-bottom{ } should be an invalid rule
 Pass	@right-top{ } should be an invalid rule
 Pass	@right-middle{ } should be an invalid rule
 Pass	@right-bottom{ } should be an invalid rule
-Fail	@page { @top-left-corner { } } should be a valid rule
+Pass	@page { @top-left-corner { } } should be a valid rule
-Fail	@page { @top-left { } } should be a valid rule
+Pass	@page { @top-left { } } should be a valid rule
-Fail	@page { @top-center { } } should be a valid rule
+Pass	@page { @top-center { } } should be a valid rule
-Fail	@page { @top-right { } } should be a valid rule
+Pass	@page { @top-right { } } should be a valid rule
-Fail	@page { @top-right-corner { } } should be a valid rule
+Pass	@page { @top-right-corner { } } should be a valid rule
-Fail	@page { @bottom-left-corner { } } should be a valid rule
+Pass	@page { @bottom-left-corner { } } should be a valid rule
-Fail	@page { @bottom-left { } } should be a valid rule
+Pass	@page { @bottom-left { } } should be a valid rule
-Fail	@page { @bottom-center { } } should be a valid rule
+Pass	@page { @bottom-center { } } should be a valid rule
-Fail	@page { @bottom-right { } } should be a valid rule
+Pass	@page { @bottom-right { } } should be a valid rule
-Fail	@page { @bottom-right-corner { } } should be a valid rule
+Pass	@page { @bottom-right-corner { } } should be a valid rule
-Fail	@page { @left-top { } } should be a valid rule
+Pass	@page { @left-top { } } should be a valid rule
-Fail	@page { @left-middle { } } should be a valid rule
+Pass	@page { @left-middle { } } should be a valid rule
-Fail	@page { @left-bottom { } } should be a valid rule
+Pass	@page { @left-bottom { } } should be a valid rule
-Fail	@page { @right-top { } } should be a valid rule
+Pass	@page { @right-top { } } should be a valid rule
-Fail	@page { @right-middle { } } should be a valid rule
+Pass	@page { @right-middle { } } should be a valid rule
-Fail	@page { @right-bottom { } } should be a valid rule
+Pass	@page { @right-bottom { } } should be a valid rule

Tests/LibWeb/Text/expected/wpt-import/css/css-page/parsing/margin-rules-002.txt

@@ -2,8 +2,9 @@ Harness status: OK
 
 Found 4 tests
 
-4 Fail
+1 Pass
-Fail	margin rule without any preceding @page properties
+3 Fail
+Pass	margin rule without any preceding @page properties
 Fail	margin rule followed by @page properties
 Fail	margin rule preceded by @page properties
 Fail	margin rules with @page properties between