diff --git a/Libraries/LibWeb/CMakeLists.txt b/Libraries/LibWeb/CMakeLists.txt
index 28cfa5721ac..e363ffe592e 100644
--- a/Libraries/LibWeb/CMakeLists.txt
+++ b/Libraries/LibWeb/CMakeLists.txt
@@ -211,6 +211,7 @@ set(SOURCES
     CSS/VisualViewport.cpp
     DOM/AbortController.cpp
     DOM/AbortSignal.cpp
+    DOM/AbstractElement.cpp
     DOM/AbstractRange.cpp
     DOM/AccessibilityTreeNode.cpp
     DOM/AdoptedStyleSheets.cpp
diff --git a/Libraries/LibWeb/CSS/CSSStyleDeclaration.h b/Libraries/LibWeb/CSS/CSSStyleDeclaration.h
index 7b4f63eddab..b3e69b3578f 100644
--- a/Libraries/LibWeb/CSS/CSSStyleDeclaration.h
+++ b/Libraries/LibWeb/CSS/CSSStyleDeclaration.h
@@ -11,7 +11,7 @@
 #include <LibWeb/Bindings/PlatformObject.h>
 #include <LibWeb/CSS/CSSStyleValue.h>
 #include <LibWeb/CSS/StyleProperty.h>
-#include <LibWeb/DOM/ElementReference.h>
+#include <LibWeb/DOM/AbstractElement.h>
 
 namespace Web::CSS {
 
@@ -50,8 +50,8 @@ public:
     void set_parent_rule(GC::Ptr<CSSRule> parent) { m_parent_rule = parent; }
 
     // https://drafts.csswg.org/cssom/#cssstyledeclaration-owner-node
-    Optional<DOM::ElementReference> owner_node() const { return m_owner_node; }
-    void set_owner_node(Optional<DOM::ElementReference> owner_node) { m_owner_node = move(owner_node); }
+    Optional<DOM::AbstractElement> owner_node() const { return m_owner_node; }
+    void set_owner_node(Optional<DOM::AbstractElement> owner_node) { m_owner_node = move(owner_node); }
 
     // https://drafts.csswg.org/cssom/#cssstyledeclaration-updating-flag
     [[nodiscard]] bool is_updating() const { return m_updating; }
@@ -80,7 +80,7 @@ private:
     GC::Ptr<CSSRule> m_parent_rule { nullptr };
 
     // https://drafts.csswg.org/cssom/#cssstyledeclaration-owner-node
-    Optional<DOM::ElementReference> m_owner_node {};
+    Optional<DOM::AbstractElement> m_owner_node {};
 
     // https://drafts.csswg.org/cssom/#cssstyledeclaration-computed-flag
     bool m_computed { false };
diff --git a/Libraries/LibWeb/CSS/CSSStyleProperties.cpp b/Libraries/LibWeb/CSS/CSSStyleProperties.cpp
index 98a7eda5d91..6f680e442bf 100644
--- a/Libraries/LibWeb/CSS/CSSStyleProperties.cpp
+++ b/Libraries/LibWeb/CSS/CSSStyleProperties.cpp
@@ -44,7 +44,7 @@ GC::Ref<CSSStyleProperties> CSSStyleProperties::create(JS::Realm& realm, Vector<
     return realm.create<CSSStyleProperties>(realm, Computed::No, Readonly::No, convert_declarations_to_specified_order(properties), move(custom_properties), OptionalNone {});
 }
 
-GC::Ref<CSSStyleProperties> CSSStyleProperties::create_resolved_style(JS::Realm& realm, Optional<DOM::ElementReference> element_reference)
+GC::Ref<CSSStyleProperties> CSSStyleProperties::create_resolved_style(JS::Realm& realm, Optional<DOM::AbstractElement> element_reference)
 {
     // https://drafts.csswg.org/cssom/#dom-window-getcomputedstyle
     // 6.  Return a live CSSStyleProperties object with the following properties:
@@ -57,7 +57,7 @@ GC::Ref<CSSStyleProperties> CSSStyleProperties::create_resolved_style(JS::Realm&
     return realm.create<CSSStyleProperties>(realm, Computed::Yes, Readonly::Yes, Vector<StyleProperty> {}, HashMap<FlyString, StyleProperty> {}, move(element_reference));
 }
 
-GC::Ref<CSSStyleProperties> CSSStyleProperties::create_element_inline_style(DOM::ElementReference element_reference, Vector<StyleProperty> properties, HashMap<FlyString, StyleProperty> custom_properties)
+GC::Ref<CSSStyleProperties> CSSStyleProperties::create_element_inline_style(DOM::AbstractElement element_reference, Vector<StyleProperty> properties, HashMap<FlyString, StyleProperty> custom_properties)
 {
     // https://drafts.csswg.org/cssom/#dom-elementcssinlinestyle-style
     // The style attribute must return a CSS declaration block object whose readonly flag is unset, whose parent CSS
@@ -66,7 +66,7 @@ GC::Ref<CSSStyleProperties> CSSStyleProperties::create_element_inline_style(DOM:
     return realm.create<CSSStyleProperties>(realm, Computed::No, Readonly::No, convert_declarations_to_specified_order(properties), move(custom_properties), move(element_reference));
 }
 
-CSSStyleProperties::CSSStyleProperties(JS::Realm& realm, Computed computed, Readonly readonly, Vector<StyleProperty> properties, HashMap<FlyString, StyleProperty> custom_properties, Optional<DOM::ElementReference> owner_node)
+CSSStyleProperties::CSSStyleProperties(JS::Realm& realm, Computed computed, Readonly readonly, Vector<StyleProperty> properties, HashMap<FlyString, StyleProperty> custom_properties, Optional<DOM::AbstractElement> owner_node)
     : CSSStyleDeclaration(realm, computed, readonly)
     , m_properties(move(properties))
     , m_custom_properties(move(custom_properties))
diff --git a/Libraries/LibWeb/CSS/CSSStyleProperties.h b/Libraries/LibWeb/CSS/CSSStyleProperties.h
index f2f7da8feca..d29f850ba08 100644
--- a/Libraries/LibWeb/CSS/CSSStyleProperties.h
+++ b/Libraries/LibWeb/CSS/CSSStyleProperties.h
@@ -22,8 +22,8 @@ class CSSStyleProperties
 public:
     [[nodiscard]] static GC::Ref<CSSStyleProperties> create(JS::Realm&, Vector<StyleProperty>, HashMap<FlyString, StyleProperty> custom_properties);
 
-    [[nodiscard]] static GC::Ref<CSSStyleProperties> create_resolved_style(JS::Realm&, Optional<DOM::ElementReference>);
-    [[nodiscard]] static GC::Ref<CSSStyleProperties> create_element_inline_style(DOM::ElementReference, Vector<StyleProperty>, HashMap<FlyString, StyleProperty> custom_properties);
+    [[nodiscard]] static GC::Ref<CSSStyleProperties> create_resolved_style(JS::Realm&, Optional<DOM::AbstractElement>);
+    [[nodiscard]] static GC::Ref<CSSStyleProperties> create_element_inline_style(DOM::AbstractElement, Vector<StyleProperty>, HashMap<FlyString, StyleProperty> custom_properties);
 
     virtual ~CSSStyleProperties() override = default;
     virtual void initialize(JS::Realm&) override;
@@ -62,7 +62,7 @@ public:
     virtual CSSStyleProperties& generated_style_properties_to_css_style_properties() override { return *this; }
 
 private:
-    CSSStyleProperties(JS::Realm&, Computed, Readonly, Vector<StyleProperty> properties, HashMap<FlyString, StyleProperty> custom_properties, Optional<DOM::ElementReference>);
+    CSSStyleProperties(JS::Realm&, Computed, Readonly, Vector<StyleProperty> properties, HashMap<FlyString, StyleProperty> custom_properties, Optional<DOM::AbstractElement>);
     static Vector<StyleProperty> convert_declarations_to_specified_order(Vector<StyleProperty>&);
 
     virtual void visit_edges(Cell::Visitor&) override;
diff --git a/Libraries/LibWeb/DOM/AbstractElement.cpp b/Libraries/LibWeb/DOM/AbstractElement.cpp
new file mode 100644
index 00000000000..04e211b539f
--- /dev/null
+++ b/Libraries/LibWeb/DOM/AbstractElement.cpp
@@ -0,0 +1,48 @@
+/*
+ * Copyright (c) 2024-2025, Sam Atkins <sam@ladybird.org>
+ *
+ * SPDX-License-Identifier: BSD-2-Clause
+ */
+
+#include <LibWeb/DOM/AbstractElement.h>
+
+namespace Web::DOM {
+
+AbstractElement::AbstractElement(GC::Ref<Element> element, Optional<CSS::PseudoElement> pseudo_element)
+    : m_element(element)
+    , m_pseudo_element(move(pseudo_element))
+{
+}
+
+void AbstractElement::visit(GC::Cell::Visitor& visitor) const
+{
+    visitor.visit(m_element);
+}
+
+GC::Ptr<Element const> AbstractElement::parent_element() const
+{
+    if (m_pseudo_element.has_value())
+        return m_element;
+    return m_element->parent_element();
+}
+
+GC::Ptr<CSS::ComputedProperties const> AbstractElement::computed_properties() const
+{
+    if (m_pseudo_element.has_value())
+        return m_element->pseudo_element_computed_properties(*m_pseudo_element);
+    return m_element->computed_properties();
+}
+
+CSS::CountersSet& AbstractElement::ensure_counters_set()
+{
+    // FIXME: Handle pseudo-elements
+    return m_element->ensure_counters_set();
+}
+
+void AbstractElement::set_counters_set(OwnPtr<CSS::CountersSet>&& counters_set)
+{
+    // FIXME: Handle pseudo-elements
+    m_element->set_counters_set(move(counters_set));
+}
+
+}
diff --git a/Libraries/LibWeb/DOM/ElementReference.h b/Libraries/LibWeb/DOM/AbstractElement.h
similarity index 56%
rename from Libraries/LibWeb/DOM/ElementReference.h
rename to Libraries/LibWeb/DOM/AbstractElement.h
index 80f656f5da4..ed4d2a22a18 100644
--- a/Libraries/LibWeb/DOM/ElementReference.h
+++ b/Libraries/LibWeb/DOM/AbstractElement.h
@@ -12,22 +12,22 @@
 
 namespace Web::DOM {
 
-class ElementReference {
+// Either an Element or a PseudoElement
+class AbstractElement {
 public:
-    ElementReference(GC::Ref<Element> element, Optional<CSS::PseudoElement> pseudo_element = {})
-        : m_element(element)
-        , m_pseudo_element(move(pseudo_element))
-    {
-    }
+    AbstractElement(GC::Ref<Element>, Optional<CSS::PseudoElement> = {});
 
     Element& element() { return m_element; }
     Element const& element() const { return m_element; }
     Optional<CSS::PseudoElement> pseudo_element() const { return m_pseudo_element; }
 
-    void visit(GC::Cell::Visitor& visitor) const
-    {
-        visitor.visit(m_element);
-    }
+    GC::Ptr<Element const> parent_element() const;
+    GC::Ptr<CSS::ComputedProperties const> computed_properties() const;
+
+    CSS::CountersSet& ensure_counters_set();
+    void set_counters_set(OwnPtr<CSS::CountersSet>&&);
+
+    void visit(GC::Cell::Visitor& visitor) const;
 
 private:
     GC::Ref<Element> m_element;
diff --git a/Libraries/LibWeb/DOM/Element.cpp b/Libraries/LibWeb/DOM/Element.cpp
index d725ca80e1a..ba8459875b7 100644
--- a/Libraries/LibWeb/DOM/Element.cpp
+++ b/Libraries/LibWeb/DOM/Element.cpp
@@ -832,7 +832,7 @@ CSS::RequiredInvalidationAfterStyleChange Element::recompute_inherited_style()
 
 GC::Ref<CSS::ComputedProperties> Element::resolved_css_values(Optional<CSS::PseudoElement> type)
 {
-    auto element_computed_style = CSS::CSSStyleProperties::create_resolved_style(realm(), ElementReference { *this, type });
+    auto element_computed_style = CSS::CSSStyleProperties::create_resolved_style(realm(), AbstractElement { *this, type });
     auto properties = heap().allocate<CSS::ComputedProperties>();
 
     for (auto i = to_underlying(CSS::first_property_id); i <= to_underlying(CSS::last_property_id); ++i) {
diff --git a/Libraries/LibWeb/Editing/Internal/Algorithms.cpp b/Libraries/LibWeb/Editing/Internal/Algorithms.cpp
index dd8f76ffcb3..68b4b466786 100644
--- a/Libraries/LibWeb/Editing/Internal/Algorithms.cpp
+++ b/Libraries/LibWeb/Editing/Internal/Algorithms.cpp
@@ -4741,7 +4741,7 @@ Optional<NonnullRefPtr<CSS::CSSStyleValue const>> resolved_value(GC::Ref<DOM::No
         return {};
 
     // Retrieve resolved style value
-    auto resolved_css_style_declaration = CSS::CSSStyleProperties::create_resolved_style(element->realm(), DOM::ElementReference { static_cast<DOM::Element&>(*element) });
+    auto resolved_css_style_declaration = CSS::CSSStyleProperties::create_resolved_style(element->realm(), DOM::AbstractElement { static_cast<DOM::Element&>(*element) });
     auto optional_style_property = resolved_css_style_declaration->property(property_id);
     if (!optional_style_property.has_value())
         return {};
diff --git a/Libraries/LibWeb/Forward.h b/Libraries/LibWeb/Forward.h
index e41f2b7a9de..45dc4e0dffb 100644
--- a/Libraries/LibWeb/Forward.h
+++ b/Libraries/LibWeb/Forward.h
@@ -339,6 +339,7 @@ namespace Web::DOM {
 
 class AbortController;
 class AbortSignal;
+class AbstractElement;
 class AbstractRange;
 class AccessibilityTreeNode;
 class Attr;
diff --git a/Libraries/LibWeb/HTML/Window.cpp b/Libraries/LibWeb/HTML/Window.cpp
index 32c220c7a1d..6607cfe2cfb 100644
--- a/Libraries/LibWeb/HTML/Window.cpp
+++ b/Libraries/LibWeb/HTML/Window.cpp
@@ -1278,7 +1278,7 @@ GC::Ref<CSS::CSSStyleDeclaration> Window::get_computed_style(DOM::Element& eleme
     // 1. Let doc be elt’s node document.
 
     // 2. Let obj be elt.
-    Optional<DOM::ElementReference> object { element };
+    Optional<DOM::AbstractElement> object { element };
 
     // 3. If pseudoElt is provided, is not the empty string, and starts with a colon, then:
     if (pseudo_element.has_value() && pseudo_element.value().starts_with(':')) {