From 5f419ca58df5aa97310f5513793f157c51f7dedf Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Mart=C3=ADn=20Lucas=20Golini?= <spartanj@gmail.com>
Date: Sun, 9 Aug 2026 19:22:00 -0300
Subject: [PATCH] Reduce allocations in CSS parsing and style updates

  - reuse reentrant property-resolution storage during variable substitution
  - skip redundant resolution-slot copies using structural source comparison
  - retain variable cache capacity and resolve variables in place
  - avoid copying canonical names for definition-backed properties
  - propagate resolved inherited properties by reference through widget trees
  - parse animation and transition declarations with allocation-light string views
  - share declaration tokenization between animation and transition parsers
  - avoid empty animation-map and action-query allocations
  - parse border radii without temporary split vectors
  - accept string views when converting UI lengths
  - format color hex values directly without string streams
  - use inline storage for small polygon point collections
  - preserve animation parsing semantics and fix longhand direction handling
  - save eeiv configuration when closing through keyboard shortcuts
  - extend animation, variable-resolution, property-name, and color tests
---
 include/eepp/math/polygon2.hpp                |   3 +-
 include/eepp/ui/css/animationdefinition.hpp   |   6 +
 include/eepp/ui/css/stylesheetproperty.hpp    |  15 +-
 include/eepp/ui/uinode.hpp                    |  17 +-
 include/eepp/ui/uistyle.hpp                   |  41 +++-
 include/eepp/ui/uiwidget.hpp                  |   1 +
 src/eepp/system/color.cpp                     |  23 +-
 src/eepp/ui/border.cpp                        |  17 +-
 src/eepp/ui/css/animationdefinition.cpp       | 179 ++++++++------
 src/eepp/ui/css/declarationparser.hpp         |  81 +++++++
 src/eepp/ui/css/stylesheetproperty.cpp        |  99 ++++----
 .../ui/css/stylesheetpropertyanimation.cpp    |   2 +-
 src/eepp/ui/css/transitiondefinition.cpp      |  77 +-----
 src/eepp/ui/uinode.cpp                        |   3 +-
 src/eepp/ui/uistyle.cpp                       | 220 +++++++++---------
 src/eepp/ui/uiwidget.cpp                      |  40 ++--
 .../unit_tests/action_transition_tests.cpp    |  55 +++++
 src/tests/unit_tests/color_parsing_tests.cpp  |   7 +
 .../unit_tests/uicss_inheritance_tests.cpp    |  83 +++++++
 src/tools/eeiv/eeiv.cpp                       |   9 +-
 20 files changed, 646 insertions(+), 332 deletions(-)
 create mode 100644 src/eepp/ui/css/declarationparser.hpp

diff --git a/include/eepp/math/polygon2.hpp b/include/eepp/math/polygon2.hpp
index dfd93b334..920f2663a 100644
--- a/include/eepp/math/polygon2.hpp
+++ b/include/eepp/math/polygon2.hpp
@@ -1,6 +1,7 @@
 #ifndef EE_MATHPOLIGON2_H
 #define EE_MATHPOLIGON2_H
 
+#include <eepp/core/small_vector.hpp>
 #include <eepp/math/line2.hpp>
 #include <eepp/math/quad2.hpp>
 #include <eepp/math/rect.hpp>
@@ -105,7 +106,7 @@ template <typename T> class Polygon2 {
 	Uint32 closestPoint( const Vector2<T>& to, T* distance = NULL );
 
   private:
-	std::vector<Vector2<T>> Vector;
+	SmallVector<Vector2<T>, 4> Vector;
 	Vector2<T> Position;
 };
 
diff --git a/include/eepp/ui/css/animationdefinition.hpp b/include/eepp/ui/css/animationdefinition.hpp
index 68aa745d3..18a89cfd1 100644
--- a/include/eepp/ui/css/animationdefinition.hpp
+++ b/include/eepp/ui/css/animationdefinition.hpp
@@ -100,6 +100,12 @@ class EE_API AnimationDefinition {
 	AnimationDirection mDirection = Normal;
 	AnimationFillMode mFillMode = None;
 	bool mPaused = false;
+
+	static bool isDirectionStringView( std::string_view str );
+	static AnimationDirection directionFromStringView( std::string_view str );
+	static bool isAnimationFillModeStringView( std::string_view str );
+	static AnimationFillMode fillModeFromStringView( std::string_view str );
+	void setNameView( std::string_view value );
 };
 
 inline bool operator==( const AnimationDefinition& a, const AnimationDefinition& b ) {
diff --git a/include/eepp/ui/css/stylesheetproperty.hpp b/include/eepp/ui/css/stylesheetproperty.hpp
index cd018ac52..01637a3ed 100644
--- a/include/eepp/ui/css/stylesheetproperty.hpp
+++ b/include/eepp/ui/css/stylesheetproperty.hpp
@@ -11,6 +11,7 @@
 #include <eepp/system/time.hpp>
 #include <eepp/ui/css/propertyids.hpp>
 #include <eepp/ui/css/stylesheetlength.hpp>
+#include <span>
 #include <string>
 
 using namespace EE::System;
@@ -19,6 +20,7 @@ using namespace EE::Graphics;
 
 namespace EE { namespace UI {
 class UINode;
+class UIStyle;
 }} // namespace EE::UI
 
 namespace EE { namespace UI { namespace CSS {
@@ -29,9 +31,15 @@ class ShorthandDefinition;
 struct VariableFunctionCache {
 	std::string definition;
 	std::vector<std::string> variableList;
+
+	void clear() { variableList.clear(); }
+
+	void addVariable( std::string_view variable ) { variableList.emplace_back( variable ); }
 };
 
 class EE_API StyleSheetProperty {
+	friend class EE::UI::UIStyle;
+
   public:
 	StyleSheetProperty();
 
@@ -196,7 +204,7 @@ class EE_API StyleSheetProperty {
 
 	const String::HashType& getValueHash() const;
 
-	const std::vector<VariableFunctionCache>& getVarCache() const;
+	std::span<const VariableFunctionCache> getVarCache() const;
 
 	StyleSheetProperty& setCachedProperty( bool cached );
 
@@ -205,6 +213,8 @@ class EE_API StyleSheetProperty {
 	void setImportant( bool important );
 
   protected:
+	bool hasSameResolutionSource( const StyleSheetProperty& property ) const;
+
 	std::string mName;
 	String::HashType mNameHash{ 0 };
 	std::string mValue;
@@ -220,6 +230,7 @@ class EE_API StyleSheetProperty {
 	const ShorthandDefinition* mShorthandDefinition{ nullptr };
 	std::vector<StyleSheetProperty> mIndexedProperty;
 	std::vector<VariableFunctionCache> mVarCache;
+	size_t mVarCacheSize{ 0 };
 
 	explicit StyleSheetProperty( bool isVolatile, const PropertyDefinition* definition,
 								 const std::string& value, const Int64& specificity = 0,
@@ -229,7 +240,7 @@ class EE_API StyleSheetProperty {
 	void checkImportant();
 	void createIndexed();
 	void checkVars();
-	std::vector<VariableFunctionCache> checkVars( const std::string& value );
+	std::string& mutableValue() { return mValue; }
 };
 
 typedef UnorderedMap<Uint32, StyleSheetProperty> StyleSheetProperties;
diff --git a/include/eepp/ui/uinode.hpp b/include/eepp/ui/uinode.hpp
index 855c1a061..ee3eef0a8 100644
--- a/include/eepp/ui/uinode.hpp
+++ b/include/eepp/ui/uinode.hpp
@@ -1151,6 +1151,13 @@ class EE_API UINode : public Node {
 	Float convertLengthAsDp( const CSS::StyleSheetLength& length,
 							 const Float& containerLength ) const;
 
+	inline Float lengthFromValue( const std::string& value,
+								  const CSS::PropertyRelativeTarget& relativeTarget,
+								  const Float& defaultValue, const Uint32& propertyIndex ) const {
+		return lengthFromValue( std::string_view{ value }, relativeTarget, defaultValue,
+								propertyIndex );
+	}
+
 	/**
 	 * @brief Evaluates a CSS length string to a pixel value.
 	 *
@@ -1163,10 +1170,18 @@ class EE_API UINode : public Node {
 	 * @param propertyIndex The property index for multi-value properties (default: 0).
 	 * @return The computed length in pixels.
 	 */
-	Float lengthFromValue( const std::string& value,
+	Float lengthFromValue( std::string_view value,
 						   const CSS::PropertyRelativeTarget& relativeTarget,
 						   const Float& defaultValue = 0, const Uint32& propertyIndex = 0 ) const;
 
+	inline Float lengthFromValue( const char* value,
+								  const CSS::PropertyRelativeTarget& relativeTarget,
+								  const Float& defaultValue = 0,
+								  const Uint32& propertyIndex = 0 ) const {
+		return lengthFromValue( std::string_view{ value }, relativeTarget, defaultValue,
+								propertyIndex );
+	}
+
 	/**
 	 * @brief Evaluates a CSS property to a pixel value.
 	 *
diff --git a/include/eepp/ui/uistyle.hpp b/include/eepp/ui/uistyle.hpp
index 58d3bd14c..c191a01db 100644
--- a/include/eepp/ui/uistyle.hpp
+++ b/include/eepp/ui/uistyle.hpp
@@ -10,7 +10,7 @@
 #include <eepp/ui/css/stylesheetstyle.hpp>
 #include <eepp/ui/css/transitiondefinition.hpp>
 #include <eepp/ui/uistate.hpp>
-#include <optional>
+#include <memory>
 
 namespace EE { namespace Graphics {
 class Font;
@@ -96,6 +96,31 @@ class EE_API UIStyle : public UIState {
 	void applyVarValues( CSS::StyleSheetProperty* style );
 
   protected:
+	class PropertyResolution {
+	  public:
+		PropertyResolution( const PropertyResolution& ) = delete;
+		PropertyResolution& operator=( const PropertyResolution& ) = delete;
+		PropertyResolution( PropertyResolution&& other ) noexcept;
+		PropertyResolution& operator=( PropertyResolution&& ) = delete;
+		~PropertyResolution();
+
+		const CSS::StyleSheetProperty* get() const { return mProperty; }
+
+	  private:
+		friend class UIStyle;
+		static constexpr Uint32 NoSlot = static_cast<Uint32>( -1 );
+
+		PropertyResolution( UIStyle* owner, const CSS::StyleSheetProperty* property,
+							Uint32 slot = NoSlot ) :
+			mOwner( owner ), mProperty( property ), mSlot( slot ) {}
+
+		void release();
+
+		UIStyle* mOwner;
+		const CSS::StyleSheetProperty* mProperty;
+		Uint32 mSlot;
+	};
+
 	UIWidget* mWidget;
 	std::shared_ptr<CSS::StyleSheetStyle> mElementStyle;
 	std::shared_ptr<CSS::ElementDefinition> mGlobalDefinition;
@@ -105,8 +130,12 @@ class EE_API UIStyle : public UIState {
 	UnorderedSet<UIWidget*> mSubscribedWidgets;
 	UnorderedSet<UIWidget*> mStructurallyVolatileChildren;
 	Uint32 mStateDepthCounter{ 0 };
+	Uint32 mPropertyResolutionDepth{ 0 };
 	Uint64 mLoadedVersion{ 0 };
 	const CSS::StyleSheet* mLoadedStyleSheet{ nullptr };
+	/** Lazily allocated for styles that use substitutions. The pointed-to properties remain stable
+	 * during nested resolutions and retain their string/vector capacities between state changes. */
+	SmallVector<std::unique_ptr<CSS::StyleSheetProperty>, 1> mPropertyResolutionSlots;
 	bool mChangingState;
 	bool mForceReapplyProperties;
 	bool mDisableAnimations;
@@ -118,7 +147,9 @@ class EE_API UIStyle : public UIState {
 
 	void applyLightDarkValue( std::string& newValue );
 
-	void setVariableFromValue( CSS::StyleSheetProperty* property, const std::string& value );
+	const CSS::StyleSheetVariable* getVariableRef( const std::string& variable );
+
+	void setVariableFromValue( CSS::StyleSheetProperty* property );
 
 	void updateState();
 
@@ -150,9 +181,9 @@ class EE_API UIStyle : public UIState {
 
 	CSS::StyleSheetProperty* getLocalProperty( CSS::PropertyId propId );
 
-	CSS::StyleSheetProperty*
-	getResolvedLocalProperty( CSS::PropertyId propId,
-							  std::optional<CSS::StyleSheetProperty>& resolvedProperty );
+	PropertyResolution resolveProperty( const CSS::StyleSheetProperty* property );
+
+	PropertyResolution getResolvedLocalProperty( CSS::PropertyId propId );
 
 	void addStructurallyVolatileWidgetFromParent();
 
diff --git a/include/eepp/ui/uiwidget.hpp b/include/eepp/ui/uiwidget.hpp
index 2772de314..49d0db5f8 100644
--- a/include/eepp/ui/uiwidget.hpp
+++ b/include/eepp/ui/uiwidget.hpp
@@ -1526,6 +1526,7 @@ class EE_API UIWidget : public UINode {
 
 	void calculateAutoMargin();
 	void rebuildClassHashes();
+	void propagateInheritedPropertyResolved( const CSS::StyleSheetProperty& property );
 
 	/**
 	 * @brief Default constructor.
diff --git a/src/eepp/system/color.cpp b/src/eepp/system/color.cpp
index c891319cd..65b4ade44 100644
--- a/src/eepp/system/color.cpp
+++ b/src/eepp/system/color.cpp
@@ -6,8 +6,6 @@
 #include <cstdlib>
 #include <cstring>
 #include <ctype.h>
-#include <iomanip>
-#include <sstream>
 #include <string_view>
 
 namespace EE { namespace System {
@@ -611,14 +609,21 @@ Color Color::div( int divisor, bool divAlpha ) {
 }
 
 std::string Color::toHexString( const bool& prependHashtag ) const {
-	std::stringstream stream;
+	static constexpr char hex[] = "0123456789abcdef";
+	const std::size_t offset = prependHashtag ? 1 : 0;
+	std::string result( offset + ( a == 255 ? 6 : 8 ), '0' );
 	if ( prependHashtag )
-		stream << "#";
-	stream << std::setfill( '0' ) << std::setw( sizeof( Color ) * 2 ) << std::hex << getValue();
-	std::string str = stream.str();
-	if ( this->a == 255 )
-		return str.substr( 0, prependHashtag ? 7 : 6 );
-	return str;
+		result[0] = '#';
+	const auto writeByte = [&]( std::size_t position, Uint8 value ) {
+		result[offset + position] = hex[value >> 4];
+		result[offset + position + 1] = hex[value & 0x0F];
+	};
+	writeByte( 0, r );
+	writeByte( 2, g );
+	writeByte( 4, b );
+	if ( a != 255 )
+		writeByte( 6, a );
+	return result;
 }
 
 std::string Color::toRgbaString() const {
diff --git a/src/eepp/ui/border.cpp b/src/eepp/ui/border.cpp
index 91af3fed6..f950d2c84 100644
--- a/src/eepp/ui/border.cpp
+++ b/src/eepp/ui/border.cpp
@@ -145,11 +145,20 @@ BorderStyle Borders::toBorderStyle( const std::string& borderStyle ) {
 }
 
 Sizef Borders::radiusFromString( const UINode* node, const std::string& val ) {
-	auto split = String::split( val, ' ' );
+	std::string_view values = String::trim( std::string_view{ val }, " \t\n\r\f\v" );
+	const auto firstEnd = values.find_first_of( " \t\n\r\f\v" );
+	const std::string_view first = values.substr( 0, firstEnd );
+	std::string_view second = first;
+	if ( firstEnd != std::string_view::npos ) {
+		values.remove_prefix( firstEnd );
+		values = String::trim( values, " \t\n\r\f\v" );
+		const auto secondEnd = values.find_first_of( " \t\n\r\f\v" );
+		if ( !values.empty() )
+			second = values.substr( 0, secondEnd );
+	}
 	Sizef size;
-	size.x = node->lengthFromValue( split[0], CSS::PropertyRelativeTarget::LocalBlockRadiusWidth );
-	size.y = node->lengthFromValue( split[split.size() > 1 ? 1 : 0],
-									CSS::PropertyRelativeTarget::LocalBlockRadiusHeight );
+	size.x = node->lengthFromValue( first, CSS::PropertyRelativeTarget::LocalBlockRadiusWidth );
+	size.y = node->lengthFromValue( second, CSS::PropertyRelativeTarget::LocalBlockRadiusHeight );
 	return size;
 }
 
diff --git a/src/eepp/ui/css/animationdefinition.cpp b/src/eepp/ui/css/animationdefinition.cpp
index 5320566ae..e096d1a24 100644
--- a/src/eepp/ui/css/animationdefinition.cpp
+++ b/src/eepp/ui/css/animationdefinition.cpp
@@ -1,26 +1,47 @@
-#include <eepp/system/functionstring.hpp>
 #include <eepp/ui/css/animationdefinition.hpp>
+#include <eepp/ui/css/declarationparser.hpp>
 #include <eepp/ui/css/propertydefinition.hpp>
 #include <eepp/ui/css/timingfunction.hpp>
 
 namespace EE { namespace UI { namespace CSS {
 
-inline bool isTimingFunction( const std::string& str ) {
-	return Ease::Interpolation::None != Ease::fromName( str, Ease::Interpolation::None );
+namespace {
+
+bool isTime( std::string_view value ) {
+	value = String::trim( value, " \t\n\r\f\v" );
+	if ( value.empty() )
+		return false;
+	auto lower = []( char character ) {
+		return character >= 'A' && character <= 'Z' ? character + ( 'a' - 'A' ) : character;
+	};
+	std::size_t suffixSize = 0;
+	if ( value.size() >= 2 && lower( value[value.size() - 2] ) == 'm' &&
+		 lower( value.back() ) == 's' )
+		suffixSize = 2;
+	else if ( lower( value.back() ) == 's' || lower( value.back() ) == 'm' )
+		suffixSize = 1;
+	if ( 0 == suffixSize || value.size() == suffixSize )
+		return false;
+	double number = 0;
+	std::string_view numberView = value.substr( 0, value.size() - suffixSize );
+	if ( !numberView.empty() && numberView.front() == '+' )
+		numberView.remove_prefix( 1 );
+	return String::fromString( number, numberView );
 }
 
+} // namespace
+
 UnorderedMap<std::string, AnimationDefinition> AnimationDefinition::parseAnimationProperties(
 	const std::vector<const StyleSheetProperty*>& stylesheetProperties ) {
 	AnimationsMap animations;
-	std::vector<std::string> names;
-	std::vector<Time> durations;
-	std::vector<Time> delays;
-	std::vector<Int32> iterations;
-	std::vector<Ease::Interpolation> timingFunctions;
-	std::vector<std::vector<double>> timingFunctionParameters;
-	std::vector<AnimationDirection> directions;
-	std::vector<AnimationFillMode> fillModes;
-	std::vector<bool> pausedStates;
+	SmallVector<std::string_view, 4> names;
+	SmallVector<Time, 4> durations;
+	SmallVector<Time, 4> delays;
+	SmallVector<Int32, 4> iterations;
+	SmallVector<TimingFunction, 4> timingFunctions;
+	SmallVector<AnimationDirection, 4> directions;
+	SmallVector<AnimationFillMode, 4> fillModes;
+	SmallVector<Uint8, 4> pausedStates;
 
 	for ( auto& prop : stylesheetProperties ) {
 		if ( prop->getPropertyDefinition() == NULL )
@@ -30,52 +51,49 @@ UnorderedMap<std::string, AnimationDefinition> AnimationDefinition::parseAnimati
 
 		switch ( propDef->getPropertyId() ) {
 			case PropertyId::Animation: {
-				bool durationSet = false;
-
 				for ( size_t i = 0; i < prop->getPropertyIndexCount(); i++ ) {
 					const StyleSheetProperty& iProp = prop->getPropertyIndex( i );
-
-					auto parts = String::split( iProp.getValue(), ' ' );
+					auto parts = DeclarationParser::splitWhitespaceTokens<8>( iProp.getValue() );
 
 					if ( parts.size() >= 2 ) {
 						AnimationDefinition animationDef;
+						bool durationSet = false;
 
-						for ( auto& part : parts ) {
-							std::string val( String::trim( String::toLower( part ) ) );
+						for ( std::string_view part : parts ) {
+							const auto hash = DeclarationParser::lowerHash( part );
 
-							if ( isDirectionString( val ) ) {
-								animationDef.setDirection( directionFromString( val ) );
-							} else if ( isAnimationFillModeString( val ) ) {
-								animationDef.setFillMode( fillModeFromString( val ) );
-							} else if ( "infinite" == val ) {
+							if ( isDirectionStringView( part ) ) {
+								animationDef.setDirection( directionFromStringView( part ) );
+							} else if ( isAnimationFillModeStringView( part ) ) {
+								animationDef.setFillMode( fillModeFromStringView( part ) );
+							} else if ( hash == String::hash( "infinite" ) ) {
 								animationDef.setIterations( -1 );
-							} else if ( "paused" == val ) {
+							} else if ( hash == String::hash( "paused" ) ) {
 								animationDef.setPaused( true );
-							} else if ( "running" == val ) {
+							} else if ( hash == String::hash( "running" ) ) {
 								animationDef.setPaused( false );
-							} else if ( isTimingFunction( val ) ) {
-								TimingFunction tf( TimingFunction::parse( val ) );
+							} else if ( TimingFunction tf = TimingFunction::parse( part );
+										Ease::Interpolation::None != tf.interpolation ) {
 								animationDef.setTimingFunction( tf.interpolation );
 								animationDef.setTimingFunctionParameters( tf.parameters );
-							} else if ( Time::isValid( val ) ) {
+							} else if ( isTime( part ) ) {
 								if ( durationSet ) {
-									animationDef.setDelay( Time::fromString( val ) );
+									animationDef.setDelay( DeclarationParser::parseTime( part ) );
 								} else {
-									animationDef.setDuration( Time::fromString( val ) );
+									animationDef.setDuration(
+										DeclarationParser::parseTime( part ) );
 									durationSet = true;
 								}
-							} else if ( String::isNumber( val, true ) ) {
-								int iterations = 1;
-
-								if ( String::fromString( iterations, val ) ) {
-									animationDef.setIterations( iterations );
-								}
+							} else if ( int iterations = 1;
+										String::fromString( iterations, part ) ) {
+								animationDef.setIterations( iterations );
 							} else {
-								animationDef.setName( part );
+								animationDef.setNameView( part );
 							}
 						}
 
-						animations[animationDef.getName()] = std::move( animationDef );
+						animations.insert_or_assign( animationDef.getName(),
+													 std::move( animationDef ) );
 					}
 				}
 				return animations;
@@ -86,41 +104,44 @@ UnorderedMap<std::string, AnimationDefinition> AnimationDefinition::parseAnimati
 			case PropertyId::AnimationDuration:
 			case PropertyId::AnimationFillMode:
 			case PropertyId::AnimationPlayState:
+			case PropertyId::AnimationDirection:
 			case PropertyId::AnimationIterationCount:
 			case PropertyId::AnimationTimingFunction: {
 				for ( size_t i = 0; i < prop->getPropertyIndexCount(); i++ ) {
 					const StyleSheetProperty& iProp = prop->getPropertyIndex( i );
-					std::string val( String::trim( String::toLower( iProp.getValue() ) ) );
+					const std::string_view val =
+						String::trim( std::string_view{ iProp.getValue() }, " \t\n\r\f\v" );
+					const auto hash = DeclarationParser::lowerHash( val );
 					switch ( propDef->getPropertyId() ) {
 						case PropertyId::AnimationName:
-							names.push_back( iProp.getValue() );
+							names.emplace_back( iProp.getValue() );
 							break;
 						case PropertyId::AnimationDelay:
-							delays.push_back( Time::fromString( val ) );
+							delays.emplace_back( DeclarationParser::parseTime( val ) );
 							break;
 						case PropertyId::AnimationDuration:
-							durations.push_back( Time::fromString( val ) );
+							durations.emplace_back( DeclarationParser::parseTime( val ) );
 							break;
 						case PropertyId::AnimationFillMode:
-							fillModes.push_back( fillModeFromString( val ) );
+							fillModes.emplace_back( fillModeFromStringView( val ) );
 							break;
 						case PropertyId::AnimationPlayState:
-							pausedStates.push_back( val == "paused" ? true : false );
+							pausedStates.emplace_back( hash == String::hash( "paused" ) );
+							break;
+						case PropertyId::AnimationDirection:
+							directions.emplace_back( directionFromStringView( val ) );
 							break;
 						case PropertyId::AnimationIterationCount: {
 							int iVal;
-							if ( val == "infinite" ) {
-								iterations.push_back( -1 );
+							if ( hash == String::hash( "infinite" ) ) {
+								iterations.emplace_back( -1 );
 							} else if ( String::fromString( iVal, val ) && iVal >= -1 ) {
-								iterations.push_back( iVal );
+								iterations.emplace_back( iVal );
 							}
 							break;
 						}
 						case PropertyId::AnimationTimingFunction: {
-							TimingFunction tf( TimingFunction::parse( val ) );
-							timingFunctions.emplace_back( tf.interpolation );
-							timingFunctionParameters.emplace_back( tf.parameters.begin(),
-																   tf.parameters.end() );
+							timingFunctions.emplace_back( TimingFunction::parse( val ) );
 							break;
 						}
 						default:
@@ -136,7 +157,7 @@ UnorderedMap<std::string, AnimationDefinition> AnimationDefinition::parseAnimati
 
 	for ( size_t i = 0; i < names.size(); i++ ) {
 		AnimationDefinition animationDef;
-		animationDef.setName( names[i] );
+		animationDef.setNameView( names[i] );
 
 		if ( !delays.empty() )
 			animationDef.setDelay( delays[i % delays.size()] );
@@ -147,35 +168,45 @@ UnorderedMap<std::string, AnimationDefinition> AnimationDefinition::parseAnimati
 		if ( !fillModes.empty() )
 			animationDef.setFillMode( fillModes[i % fillModes.size()] );
 
+		if ( !directions.empty() )
+			animationDef.setDirection( directions[i % directions.size()] );
+
 		if ( !pausedStates.empty() )
 			animationDef.setPaused( pausedStates[i % pausedStates.size()] );
 
 		if ( !iterations.empty() )
 			animationDef.setIterations( iterations[i % iterations.size()] );
 
-		if ( !timingFunctions.empty() )
-			animationDef.setTimingFunction( timingFunctions[i % timingFunctions.size()] );
+		if ( !timingFunctions.empty() ) {
+			const TimingFunction& timing = timingFunctions[i % timingFunctions.size()];
+			animationDef.setTimingFunction( timing.interpolation );
+			animationDef.setTimingFunctionParameters( timing.parameters );
+		}
 
-		if ( !timingFunctionParameters.empty() )
-			animationDef.setTimingFunctionParameters(
-				timingFunctionParameters[i % timingFunctionParameters.size()] );
-
-		animations[animationDef.getName()] = std::move( animationDef );
+		animations.insert_or_assign( animationDef.getName(), std::move( animationDef ) );
 	}
 
 	return animations;
 }
 
 bool AnimationDefinition::isDirectionString( const std::string str ) {
-	String::HashType id = String::hash( str );
+	return isDirectionStringView( str );
+}
+
+bool AnimationDefinition::isDirectionStringView( std::string_view str ) {
+	String::HashType id = DeclarationParser::lowerHash( str );
 	return id == AlternateReverse || id == Alternate || id == Reverse || id == Normal;
 }
 
 AnimationDefinition::AnimationDirection
 AnimationDefinition::directionFromString( std::string str ) {
-	String::trimInPlace( str );
-	String::toLowerInPlace( str );
-	switch ( String::hash( str ) ) {
+	return directionFromStringView( str );
+}
+
+AnimationDefinition::AnimationDirection
+AnimationDefinition::directionFromStringView( std::string_view str ) {
+	str = String::trim( str, " \t\n\r\f\v" );
+	switch ( DeclarationParser::lowerHash( str ) ) {
 		case AlternateReverse:
 			return AlternateReverse;
 		case Alternate:
@@ -189,14 +220,22 @@ AnimationDefinition::directionFromString( std::string str ) {
 }
 
 bool AnimationDefinition::isAnimationFillModeString( const std::string& str ) {
-	Uint32 id = String::hash( str );
+	return isAnimationFillModeStringView( str );
+}
+
+bool AnimationDefinition::isAnimationFillModeStringView( std::string_view str ) {
+	Uint32 id = DeclarationParser::lowerHash( str );
 	return id == None || id == Forwards || id == Backwards || id == Both;
 }
 
 AnimationDefinition::AnimationFillMode AnimationDefinition::fillModeFromString( std::string str ) {
-	String::trimInPlace( str );
-	String::toLowerInPlace( str );
-	switch ( String::hash( str ) ) {
+	return fillModeFromStringView( str );
+}
+
+AnimationDefinition::AnimationFillMode
+AnimationDefinition::fillModeFromStringView( std::string_view str ) {
+	str = String::trim( str, " \t\n\r\f\v" );
+	switch ( DeclarationParser::lowerHash( str ) ) {
 		case None:
 			return None;
 		case Forwards:
@@ -240,7 +279,11 @@ const Ease::Interpolation& AnimationDefinition::getTimingFunction() const {
 }
 
 void AnimationDefinition::setName( const std::string& value ) {
-	mName = value;
+	setNameView( value );
+}
+
+void AnimationDefinition::setNameView( std::string_view value ) {
+	mName.assign( value );
 	mId = String::hash( mName );
 }
 
diff --git a/src/eepp/ui/css/declarationparser.hpp b/src/eepp/ui/css/declarationparser.hpp
new file mode 100644
index 000000000..3f8617a73
--- /dev/null
+++ b/src/eepp/ui/css/declarationparser.hpp
@@ -0,0 +1,81 @@
+#ifndef EE_UI_CSS_DECLARATIONPARSER_HPP
+#define EE_UI_CSS_DECLARATIONPARSER_HPP
+
+#include <cctype>
+#include <eepp/core/small_vector.hpp>
+#include <eepp/core/string.hpp>
+#include <eepp/system/functionstring.hpp>
+#include <eepp/system/time.hpp>
+
+namespace EE { namespace UI { namespace CSS { namespace DeclarationParser {
+
+template <typename Callback> void forEachCommaItem( std::string_view value, Callback&& callback ) {
+	System::FunctionString::forEachParameter( value, [&]( std::string_view item, bool ) {
+		callback( item );
+		return true;
+	} );
+}
+
+template <std::size_t InlineCapacity>
+SmallVector<std::string_view, InlineCapacity> splitWhitespaceTokens( std::string_view value ) {
+	SmallVector<std::string_view, InlineCapacity> tokens;
+	std::size_t start = 0;
+	int parenthesisDepth = 0;
+	for ( std::size_t i = 0; i <= value.size(); ++i ) {
+		if ( i < value.size() ) {
+			if ( value[i] == '(' )
+				++parenthesisDepth;
+			else if ( value[i] == ')' && parenthesisDepth > 0 )
+				--parenthesisDepth;
+		}
+		if ( i == value.size() ||
+			 ( std::isspace( static_cast<unsigned char>( value[i] ) ) && parenthesisDepth == 0 ) ) {
+			if ( i > start )
+				tokens.emplace_back( value.substr( start, i - start ) );
+			while ( i + 1 < value.size() &&
+					std::isspace( static_cast<unsigned char>( value[i + 1] ) ) )
+				++i;
+			start = i + 1;
+		}
+	}
+	return tokens;
+}
+
+inline System::Time parseTime( std::string_view value ) {
+	value = String::trim( value, " \t\n\r\f\v" );
+	auto lower = []( char character ) {
+		return character >= 'A' && character <= 'Z' ? character + ( 'a' - 'A' ) : character;
+	};
+	bool milliseconds = value.size() >= 2 && lower( value[value.size() - 2] ) == 'm' &&
+						lower( value.back() ) == 's';
+	bool seconds = !milliseconds && !value.empty() && lower( value.back() ) == 's';
+	bool minutes = !milliseconds && !seconds && !value.empty() && lower( value.back() ) == 'm';
+	std::size_t numberLength = value.size() - ( milliseconds ? 2 : ( seconds || minutes ? 1 : 0 ) );
+	double number = 0;
+	const char* numberStart = value.data();
+	if ( numberLength > 0 && *numberStart == '+' ) {
+		++numberStart;
+		--numberLength;
+	}
+	if ( !String::fromString( number, std::string_view{ numberStart, numberLength } ) )
+		return System::Time::Zero;
+	if ( milliseconds )
+		return System::Milliseconds( number );
+	if ( minutes )
+		return System::Minutes( number );
+	return System::Seconds( number );
+}
+
+inline String::HashType lowerHash( std::string_view value ) {
+	return String::hashToLower( value.data(), static_cast<Int64>( value.size() ) );
+}
+
+inline std::string lowerString( std::string_view value ) {
+	std::string result{ value };
+	String::toLowerInPlace( result );
+	return result;
+}
+
+}}}} // namespace EE::UI::CSS::DeclarationParser
+
+#endif
diff --git a/src/eepp/ui/css/stylesheetproperty.cpp b/src/eepp/ui/css/stylesheetproperty.cpp
index ebaa6f70b..8cd65dd7a 100644
--- a/src/eepp/ui/css/stylesheetproperty.cpp
+++ b/src/eepp/ui/css/stylesheetproperty.cpp
@@ -23,7 +23,6 @@ StyleSheetProperty::StyleSheetProperty() :
 StyleSheetProperty::StyleSheetProperty( const PropertyDefinition* definition,
 										const std::string& value, const Uint32& index,
 										bool trimValue, bool cachedProperty ) :
-	mName( definition->getName() ),
 	mNameHash( definition->getId() ),
 	mValue( trimValue ? String::trim( value ) : value ),
 	mValueHash( String::hash( mValue ) ),
@@ -40,17 +39,11 @@ StyleSheetProperty::StyleSheetProperty( const PropertyDefinition* definition,
 	checkImportant();
 	createIndexed();
 	checkVars();
-
-	if ( NULL == mShorthandDefinition && NULL == mPropertyDefinition &&
-		 !String::startsWith( mName, "-" ) && !isDataPropertyName( mName ) ) {
-		Log::warning( "Property \"%s\" is not defined!", mName );
-	}
 }
 
 StyleSheetProperty::StyleSheetProperty( bool isVolatile, const PropertyDefinition* definition,
 										const std::string& value, const Int64& /*specificity*/,
 										const Uint32& index ) :
-	mName( definition->getName() ),
 	mNameHash( definition->getId() ),
 	mValue( String::trim( value ) ),
 	mValueHash( String::hash( mValue ) ),
@@ -64,11 +57,6 @@ StyleSheetProperty::StyleSheetProperty( bool isVolatile, const PropertyDefinitio
 	cleanValue();
 	checkImportant();
 	checkVars();
-
-	if ( NULL == mShorthandDefinition && NULL == mPropertyDefinition &&
-		 !String::startsWith( mName, "-" ) && !isDataPropertyName( mName ) ) {
-		Log::warning( "Property \"%s\" is not defined!", mName );
-	}
 }
 
 StyleSheetProperty::StyleSheetProperty( const std::string& name, const std::string& value,
@@ -140,6 +128,12 @@ ShorthandId StyleSheetProperty::getShorthandId() const {
 }
 
 const std::string& StyleSheetProperty::getName() const {
+	if ( !mName.empty() )
+		return mName;
+	if ( nullptr != mPropertyDefinition )
+		return mPropertyDefinition->getName();
+	if ( nullptr != mShorthandDefinition )
+		return mShorthandDefinition->getName();
 	return mName;
 }
 
@@ -162,7 +156,7 @@ void StyleSheetProperty::setSpecificity( const Int64& specificity ) {
 }
 
 bool StyleSheetProperty::isEmpty() const {
-	return mName.empty();
+	return mName.empty() && nullptr == mPropertyDefinition && nullptr == mShorthandDefinition;
 }
 
 void StyleSheetProperty::setName( const std::string& name ) {
@@ -174,7 +168,6 @@ void StyleSheetProperty::setValue( const std::string& value, bool updateHash ) {
 	mValue = value;
 	if ( updateHash )
 		mValueHash = String::hash( value );
-	mVarCache.clear();
 	mIsVarValue = false;
 	mIsLightDarkValue = false;
 	createIndexed();
@@ -197,6 +190,26 @@ bool StyleSheetProperty::operator!=( const StyleSheetProperty& property ) const
 	return mNameHash != property.mNameHash || mValueHash != property.mValueHash;
 }
 
+bool StyleSheetProperty::hasSameResolutionSource( const StyleSheetProperty& property ) const {
+	if ( mName != property.mName || mNameHash != property.mNameHash || mValue != property.mValue ||
+		 mValueHash != property.mValueHash || mSpecificity != property.mSpecificity ||
+		 mIndex != property.mIndex || mVolatile != property.mVolatile ||
+		 mImportant != property.mImportant || mIsVarValue != property.mIsVarValue ||
+		 mIsLightDarkValue != property.mIsLightDarkValue ||
+		 mCachedProperty != property.mCachedProperty ||
+		 mPropertyDefinition != property.mPropertyDefinition ||
+		 mShorthandDefinition != property.mShorthandDefinition ||
+		 mIndexedProperty.size() != property.mIndexedProperty.size() )
+		return false;
+
+	for ( size_t i = 0; i < mIndexedProperty.size(); ++i ) {
+		if ( !mIndexedProperty[i].hasSameResolutionSource( property.mIndexedProperty[i] ) )
+			return false;
+	}
+
+	return true;
+}
+
 const String::HashType& StyleSheetProperty::getNameHash() const {
 	return mNameHash;
 }
@@ -225,52 +238,46 @@ void StyleSheetProperty::createIndexed() {
 }
 
 void StyleSheetProperty::checkVars() {
-	auto varCache( checkVars( mValue ) );
+	mVarCacheSize = 0;
 	mIsVarValue = false;
-	if ( !varCache.empty() ) {
-		mIsVarValue = true;
-		mVarCache = std::move( varCache );
-	}
-
-	mIsLightDarkValue = mValue.find( "light-dark(" ) != std::string::npos;
-}
-
-static void varToVal( VariableFunctionCache& varCache, const std::string& varDef ) {
-	FunctionString functionType = FunctionString::parse( varDef );
-	if ( !functionType.getParameters().empty() ) {
+	auto varToVal = []( auto&& self, VariableFunctionCache& varCache,
+						std::string_view varDef ) -> void {
+		auto function = FunctionString::parseView( varDef );
+		if ( function.isEmpty() )
+			return;
 		bool foundVar = false;
-		for ( auto& val : functionType.getParameters() ) {
+		function.forEachParameter( [&]( std::string_view val, bool ) {
 			if ( String::startsWith( val, "--" ) ) {
-				varCache.variableList.emplace_back( val );
+				varCache.addVariable( val );
 				foundVar = true;
 			} else if ( String::startsWith( val, "var(" ) ) {
-				varToVal( varCache, val );
+				self( self, varCache, val );
 				foundVar = true;
 			} else if ( foundVar ) {
 				// This is a fallback value (comes after the variable name)
-				varCache.variableList.emplace_back( val );
+				varCache.addVariable( val );
 			}
-		}
-	}
-}
+			return true;
+		} );
+	};
 
-std::vector<VariableFunctionCache> StyleSheetProperty::checkVars( const std::string& value ) {
-	std::vector<VariableFunctionCache> vars;
 	std::string::size_type tokenStart = 0;
-	std::string::size_type tokenEnd = 0;
 
 	while ( true ) {
-		tokenStart = value.find( "var(", tokenStart );
+		tokenStart = mValue.find( "var(", tokenStart );
 		if ( tokenStart != std::string::npos ) {
-			tokenEnd = String::findCloseBracket( value, tokenStart, '(', ')' );
+			const std::string::size_type tokenEnd =
+				String::findCloseBracket( mValue, tokenStart, '(', ')' );
 			if ( tokenEnd != std::string::npos ) {
 				mIsVarValue = true;
-				VariableFunctionCache variableFuncCache;
-				variableFuncCache.definition =
-					value.substr( tokenStart, tokenEnd + 1 - tokenStart );
-				varToVal( variableFuncCache, variableFuncCache.definition );
+				if ( mVarCacheSize >= mVarCache.size() )
+					mVarCache.emplace_back();
+				VariableFunctionCache& variableFuncCache = mVarCache[mVarCacheSize++];
+				variableFuncCache.clear();
+				variableFuncCache.definition.assign( mValue, tokenStart,
+													 tokenEnd + 1 - tokenStart );
+				varToVal( varToVal, variableFuncCache, variableFuncCache.definition );
 				tokenStart = tokenEnd;
-				vars.emplace_back( std::move( variableFuncCache ) );
 			} else {
 				break;
 			}
@@ -279,7 +286,7 @@ std::vector<VariableFunctionCache> StyleSheetProperty::checkVars( const std::str
 		}
 	};
 
-	return vars;
+	mIsLightDarkValue = mValue.find( "light-dark(" ) != std::string::npos;
 }
 
 std::string StyleSheetProperty::asString( const std::string& defaultValue ) const {
@@ -753,8 +760,8 @@ const String::HashType& StyleSheetProperty::getValueHash() const {
 	return mValueHash;
 }
 
-const std::vector<VariableFunctionCache>& StyleSheetProperty::getVarCache() const {
-	return mVarCache;
+std::span<const VariableFunctionCache> StyleSheetProperty::getVarCache() const {
+	return { mVarCache.data(), mVarCacheSize };
 }
 
 StyleSheetProperty& StyleSheetProperty::setCachedProperty( bool cached ) {
diff --git a/src/eepp/ui/css/stylesheetpropertyanimation.cpp b/src/eepp/ui/css/stylesheetpropertyanimation.cpp
index a92a055bd..9947b595c 100644
--- a/src/eepp/ui/css/stylesheetpropertyanimation.cpp
+++ b/src/eepp/ui/css/stylesheetpropertyanimation.cpp
@@ -73,7 +73,7 @@ void StyleSheetPropertyAnimation::tweenProperty(
 				static_cast<Int32>( startColor.a + ( endColor.a - startColor.a ) * progress ),
 				255 ) );
 			widget->applyProperty(
-				StyleSheetProperty( property, resColor.toHexString(), propertyIndex ) );
+					StyleSheetProperty( property, resColor.toHexString(), propertyIndex ) );
 			break;
 		}
 		case PropertyType::NumberLength: {
diff --git a/src/eepp/ui/css/transitiondefinition.cpp b/src/eepp/ui/css/transitiondefinition.cpp
index 64f3670f4..278d56400 100644
--- a/src/eepp/ui/css/transitiondefinition.cpp
+++ b/src/eepp/ui/css/transitiondefinition.cpp
@@ -1,81 +1,12 @@
-#include <cctype>
 #include <eepp/core/string.hpp>
-#include <eepp/system/functionstring.hpp>
+#include <eepp/ui/css/declarationparser.hpp>
 #include <eepp/ui/css/propertydefinition.hpp>
 #include <eepp/ui/css/timingfunction.hpp>
 #include <eepp/ui/css/transitiondefinition.hpp>
 
 namespace EE { namespace UI { namespace CSS {
 
-namespace {
-
-template <typename Callback> void forEachCommaItem( std::string_view value, Callback&& callback ) {
-	System::FunctionString::forEachParameter( value, [&]( std::string_view item, bool ) {
-		callback( item );
-		return true;
-	} );
-}
-
-SmallVector<std::string_view, 4> splitTransitionTokens( std::string_view value ) {
-	SmallVector<std::string_view, 4> tokens;
-	std::size_t start = 0;
-	int parenthesisDepth = 0;
-	for ( std::size_t i = 0; i <= value.size(); ++i ) {
-		if ( i < value.size() ) {
-			if ( value[i] == '(' )
-				++parenthesisDepth;
-			else if ( value[i] == ')' && parenthesisDepth > 0 )
-				--parenthesisDepth;
-		}
-		if ( i == value.size() ||
-			 ( std::isspace( static_cast<unsigned char>( value[i] ) ) && parenthesisDepth == 0 ) ) {
-			if ( i > start )
-				tokens.emplace_back( value.substr( start, i - start ) );
-			while ( i + 1 < value.size() &&
-					std::isspace( static_cast<unsigned char>( value[i + 1] ) ) )
-				++i;
-			start = i + 1;
-		}
-	}
-	return tokens;
-}
-
-Time parseTime( std::string_view value ) {
-	value = String::trim( value, " \t\n\r\f\v" );
-	auto lower = []( char character ) {
-		return character >= 'A' && character <= 'Z' ? character + ( 'a' - 'A' ) : character;
-	};
-	bool milliseconds = value.size() >= 2 && lower( value[value.size() - 2] ) == 'm' &&
-						lower( value.back() ) == 's';
-	bool seconds = !milliseconds && !value.empty() && lower( value.back() ) == 's';
-	bool minutes = !milliseconds && !seconds && !value.empty() && lower( value.back() ) == 'm';
-	std::size_t numberLength = value.size() - ( milliseconds ? 2 : ( seconds || minutes ? 1 : 0 ) );
-	double number = 0;
-	const char* numberStart = value.data();
-	if ( numberLength > 0 && *numberStart == '+' ) {
-		++numberStart;
-		--numberLength;
-	}
-	if ( !String::fromString( number, std::string_view{ numberStart, numberLength } ) )
-		return Time::Zero;
-	if ( milliseconds )
-		return Milliseconds( number );
-	if ( minutes )
-		return Minutes( number );
-	return Seconds( number );
-}
-
-String::HashType lowerHash( std::string_view value ) {
-	return String::hashToLower( value.data(), static_cast<Int64>( value.size() ) );
-}
-
-std::string lowerString( std::string_view value ) {
-	std::string result{ value };
-	String::toLowerInPlace( result );
-	return result;
-}
-
-} // namespace
+using namespace DeclarationParser;
 
 UnorderedMap<std::string, TransitionDefinition> TransitionDefinition::parseTransitionProperties(
 	const std::vector<const StyleSheetProperty*>& styleSheetProperties ) {
@@ -92,7 +23,7 @@ UnorderedMap<std::string, TransitionDefinition> TransitionDefinition::parseTrans
 		switch ( property->getPropertyDefinition()->getPropertyId() ) {
 			case PropertyId::Transition:
 				forEachCommaItem( property->getValue(), [&]( std::string_view item ) {
-					auto tokens = splitTransitionTokens( item );
+					auto tokens = splitWhitespaceTokens<4>( item );
 					if ( tokens.size() < 2 )
 						return;
 					TransitionDefinition transition;
@@ -192,7 +123,7 @@ ComputedTransitions::parse( const std::vector<const StyleSheetProperty*>& styleS
 		switch ( property->getPropertyDefinition()->getPropertyId() ) {
 			case PropertyId::Transition:
 				forEachCommaItem( property->getValue(), [&]( std::string_view item ) {
-					auto tokens = splitTransitionTokens( item );
+					auto tokens = splitWhitespaceTokens<4>( item );
 					if ( tokens.size() < 2 )
 						return;
 					ComputedTransitionDefinition transition;
diff --git a/src/eepp/ui/uinode.cpp b/src/eepp/ui/uinode.cpp
index b9df6fff6..35b379ea4 100644
--- a/src/eepp/ui/uinode.cpp
+++ b/src/eepp/ui/uinode.cpp
@@ -1678,8 +1678,7 @@ Float UINode::getPropertyRelativeTargetContainerLength(
 	return containerLength;
 }
 
-Float UINode::lengthFromValue( const std::string& value,
-							   const PropertyRelativeTarget& relativeTarget,
+Float UINode::lengthFromValue( std::string_view value, const PropertyRelativeTarget& relativeTarget,
 							   const Float& defaultValue, const Uint32& propertyIndex ) const {
 	Float containerLength =
 		getPropertyRelativeTargetContainerLength( relativeTarget, defaultValue, propertyIndex );
diff --git a/src/eepp/ui/uistyle.cpp b/src/eepp/ui/uistyle.cpp
index a2a7f01f7..b837adca1 100644
--- a/src/eepp/ui/uistyle.cpp
+++ b/src/eepp/ui/uistyle.cpp
@@ -6,7 +6,6 @@
 #include <eepp/ui/uistyle.hpp>
 #include <eepp/ui/uithememanager.hpp>
 #include <eepp/ui/uiwidget.hpp>
-#include <optional>
 
 using namespace EE::UI::CSS;
 using namespace EE::Scene;
@@ -17,18 +16,6 @@ UIStyle* UIStyle::New( UIWidget* widget ) {
 	return eeNew( UIStyle, ( widget ) );
 }
 
-static const StyleSheetProperty&
-resolveInheritedProperty( UIStyle* inheritedStyle, StyleSheetProperty* inheritedProperty,
-						  std::optional<StyleSheetProperty>& resolvedProperty ) {
-	if ( inheritedStyle && inheritedProperty->needsValueSubstitution() ) {
-		resolvedProperty.emplace( *inheritedProperty );
-		inheritedStyle->applyVarValues( &*resolvedProperty );
-		return *resolvedProperty;
-	}
-
-	return *inheritedProperty;
-}
-
 UIStyle::UIStyle( UIWidget* widget ) :
 	UIState(),
 	mWidget( widget ),
@@ -46,6 +33,27 @@ UIStyle::~UIStyle() {
 	unsubscribeNonCacheableStyles();
 }
 
+UIStyle::PropertyResolution::PropertyResolution( PropertyResolution&& other ) noexcept :
+	mOwner( other.mOwner ), mProperty( other.mProperty ), mSlot( other.mSlot ) {
+	other.mOwner = nullptr;
+	other.mProperty = nullptr;
+	other.mSlot = NoSlot;
+}
+
+UIStyle::PropertyResolution::~PropertyResolution() {
+	release();
+}
+
+void UIStyle::PropertyResolution::release() {
+	if ( nullptr == mOwner || NoSlot == mSlot )
+		return;
+	eeASSERT( mOwner->mPropertyResolutionDepth == mSlot + 1 );
+	--mOwner->mPropertyResolutionDepth;
+	mOwner = nullptr;
+	mProperty = nullptr;
+	mSlot = NoSlot;
+}
+
 bool UIStyle::stateExists( const EE::Uint32& ) const {
 	return true;
 }
@@ -118,10 +126,8 @@ void UIStyle::applyInheritedProperties() {
 			UIStyle* inheritedStyle = nullptr;
 			auto inheritedProp = getInheritedProperty( propId, &inheritedStyle );
 			if ( inheritedProp ) {
-				std::optional<StyleSheetProperty> resolvedProperty;
-				const auto& propertyToApply =
-					resolveInheritedProperty( inheritedStyle, inheritedProp, resolvedProperty );
-				mWidget->applyProperty( propertyToApply );
+				auto resolvedProperty = inheritedStyle->resolveProperty( inheritedProp );
+				mWidget->applyProperty( *resolvedProperty.get() );
 			}
 		}
 	}
@@ -140,15 +146,14 @@ bool UIStyle::hasTransition( const std::string& propertyName ) {
 }
 
 StyleSheetPropertyAnimation* UIStyle::getAnimation( const PropertyDefinition* propertyDef ) {
-	std::vector<Action*> actions = mWidget->getActionsByTag( propertyDef->getId() );
-	if ( !actions.empty() ) {
-		for ( auto& action : actions ) {
-			if ( action->getId() == StyleSheetPropertyAnimation::ID ) {
-				StyleSheetPropertyAnimation* animation =
-					static_cast<StyleSheetPropertyAnimation*>( action );
-				if ( animation->getAnimationOrigin() == AnimationOrigin::Animation ) {
-					return animation;
-				}
+	SmallVector<Action*, 4> actions;
+	mWidget->getActionsByTag( propertyDef->getId(), actions );
+	for ( auto* action : actions ) {
+		if ( action->getId() == StyleSheetPropertyAnimation::ID ) {
+			StyleSheetPropertyAnimation* animation =
+				static_cast<StyleSheetPropertyAnimation*>( action );
+			if ( animation->getAnimationOrigin() == AnimationOrigin::Animation ) {
+				return animation;
 			}
 		}
 	}
@@ -181,36 +186,46 @@ const bool& UIStyle::isChangingState() const {
 }
 
 StyleSheetVariable UIStyle::getVariable( const std::string& variable ) {
+	const StyleSheetVariable* resolved = getVariableRef( variable );
+	return resolved ? *resolved : StyleSheetVariable();
+}
+
+const StyleSheetVariable* UIStyle::getVariableRef( const std::string& variable ) {
 	if ( NULL != mWidget && NULL != mWidget->getUISceneNode() )
 		resetGlobalDefinition();
 
-	StyleSheetVariable localVariable =
-		mElementStyle ? mElementStyle->getVariableByName( variable ) : StyleSheetVariable();
+	const auto nameHash = String::hash( variable );
+	const StyleSheetVariable* localVariable = nullptr;
+	if ( mElementStyle ) {
+		auto it = mElementStyle->getVariables().find( nameHash );
+		if ( it != mElementStyle->getVariables().end() )
+			localVariable = &it->second;
+	}
 
 	if ( NULL != mGlobalDefinition ) {
-		auto it = mGlobalDefinition->getVariables().find( String::hash( variable ) );
+		auto it = mGlobalDefinition->getVariables().find( nameHash );
 
 		if ( it != mGlobalDefinition->getVariables().end() ) {
-			if ( localVariable.isEmpty() ||
-				 it->second.getSpecificity() > localVariable.getSpecificity() )
-				return it->second;
+			if ( nullptr == localVariable ||
+				 it->second.getSpecificity() > localVariable->getSpecificity() )
+				return &it->second;
 		}
 	}
 
-	if ( !localVariable.isEmpty() )
+	if ( nullptr != localVariable )
 		return localVariable;
 
-	Node* parentWidget = mWidget->getParentWidget();
+	Node* parentWidget = mWidget ? mWidget->getParentWidget() : nullptr;
 
 	if ( NULL != parentWidget ) {
 		UIStyle* style = parentWidget->asType<UIWidget>()->getUIStyle();
 
 		if ( NULL != style ) {
-			return style->getVariable( variable );
+			return style->getVariableRef( variable );
 		}
 	}
 
-	return StyleSheetVariable();
+	return nullptr;
 }
 
 bool UIStyle::getForceReapplyProperties() const {
@@ -334,22 +349,22 @@ void UIStyle::applyLightDarkValue( std::string& value ) {
 	};
 }
 
-void UIStyle::setVariableFromValue( StyleSheetProperty* property, const std::string& value ) {
+void UIStyle::setVariableFromValue( StyleSheetProperty* property ) {
 	if ( property->getVarCache().empty() && !property->isLightDarkValue() )
 		return;
 
-	std::string newValue( value );
+	std::string& value = property->mutableValue();
 	static constexpr int maxDepth = 16;
 
 	for ( int depth = 0; depth < maxDepth; depth++ ) {
 		bool changed = false;
 		if ( !property->getVarCache().empty() ) {
-			const auto& varCache = property->getVarCache();
+			const auto varCache = property->getVarCache();
 			for ( const auto& var : varCache ) {
 				for ( const auto& val : var.variableList ) {
-					StyleSheetVariable variable( getVariable( val ) );
-					if ( !variable.isEmpty() ) {
-						String::replaceAll( newValue, var.definition, variable.getValue() );
+					const StyleSheetVariable* variable = getVariableRef( val );
+					if ( nullptr != variable ) {
+						String::replaceAll( value, var.definition, variable->getValue() );
 						changed = true;
 						break;
 					}
@@ -357,12 +372,12 @@ void UIStyle::setVariableFromValue( StyleSheetProperty* property, const std::str
 			}
 		}
 		if ( property->isLightDarkValue() ) {
-			applyLightDarkValue( newValue );
+			applyLightDarkValue( value );
 			changed = true;
 		}
 		if ( !changed )
 			break;
-		property->setValue( newValue );
+		property->setValue( value );
 		if ( property->getVarCache().empty() && !property->isLightDarkValue() )
 			break;
 	}
@@ -377,10 +392,10 @@ void UIStyle::applyVarValues( StyleSheetProperty* property ) {
 			 property->getPropertyIndexCount() > 0 ) {
 			for ( size_t i = 0; i < property->getPropertyIndexCount(); i++ ) {
 				StyleSheetProperty* realProperty = property->getPropertyIndexRef( i );
-				setVariableFromValue( realProperty, realProperty->getValue() );
+				setVariableFromValue( realProperty );
 			}
 		} else {
-			setVariableFromValue( property, property->getValue() );
+			setVariableFromValue( property );
 		}
 	}
 }
@@ -438,8 +453,8 @@ void UIStyle::onStateChange() {
 		mWidget->beginAttributesTransaction();
 
 		for ( PropertyId prop : changedProperties ) {
-			std::optional<StyleSheetProperty> resolvedProperty;
-			StyleSheetProperty* property = getResolvedLocalProperty( prop, resolvedProperty );
+			auto resolvedProperty = getResolvedLocalProperty( prop );
+			const StyleSheetProperty* property = resolvedProperty.get();
 
 			if ( nullptr == property || NULL == property->getPropertyDefinition() ) {
 				const auto def = StyleSheetSpecification::instance()->getProperty( prop );
@@ -448,11 +463,10 @@ void UIStyle::onStateChange() {
 					StyleSheetProperty* inheritedProp =
 						getInheritedProperty( prop, &inheritedStyle );
 					if ( inheritedProp ) {
-						std::optional<StyleSheetProperty> resolvedInheritedProperty;
-						const auto& inheritedPropertyToApply = resolveInheritedProperty(
-							inheritedStyle, inheritedProp, resolvedInheritedProperty );
-						mWidget->applyProperty( inheritedPropertyToApply );
-						mWidget->propagateInheritedProperty( inheritedPropertyToApply );
+						auto resolvedInheritedProperty =
+							inheritedStyle->resolveProperty( inheritedProp );
+						mWidget->applyProperty( *resolvedInheritedProperty.get() );
+						mWidget->propagateInheritedProperty( *resolvedInheritedProperty.get() );
 					}
 				}
 				continue;
@@ -478,11 +492,10 @@ void UIStyle::onStateChange() {
 							mWidget->propagateInheritedProperty( resolved );
 						}
 					} else {
-						std::optional<StyleSheetProperty> resolvedInheritedProperty;
-						const auto& inheritedPropertyToApply = resolveInheritedProperty(
-							inheritedStyle, inheritedProp, resolvedInheritedProperty );
-						mWidget->applyProperty( inheritedPropertyToApply );
-						mWidget->propagateInheritedProperty( inheritedPropertyToApply );
+						auto resolvedInheritedProperty =
+							inheritedStyle->resolveProperty( inheritedProp );
+						mWidget->applyProperty( *resolvedInheritedProperty.get() );
+						mWidget->propagateInheritedProperty( *resolvedInheritedProperty.get() );
 					}
 				}
 			} else {
@@ -612,13 +625,8 @@ void UIStyle::removeRelatedWidgets() {
 
 void UIStyle::applyStyleSheetProperty( const StyleSheetProperty& originalProperty,
 									   std::shared_ptr<ElementDefinition> prevDefinition ) {
-	const StyleSheetProperty* property = &originalProperty;
-	std::optional<StyleSheetProperty> resolvedProperty;
-	if ( originalProperty.needsValueSubstitution() ) {
-		resolvedProperty.emplace( originalProperty );
-		applyVarValues( &*resolvedProperty );
-		property = &*resolvedProperty;
-	}
+	auto resolvedProperty = resolveProperty( &originalProperty );
+	const StyleSheetProperty* property = resolvedProperty.get();
 
 	const PropertyDefinition* propertyDefinition = property->getPropertyDefinition();
 
@@ -650,20 +658,13 @@ void UIStyle::applyStyleSheetProperty( const StyleSheetProperty& originalPropert
 			if ( nullptr != prevDefinition ) {
 				auto prevProp = prevDefinition->getProperty( property->getPropertyId() );
 				if ( nullptr != prevProp ) {
-					StyleSheetProperty* curProperty = prevProp;
-					std::optional<StyleSheetProperty> resolvedPrevProperty;
-					if ( prevProp->needsValueSubstitution() ) {
-						resolvedPrevProperty.emplace( *prevProp );
-						curProperty = &*resolvedPrevProperty;
-					}
+					auto resolvedPrevProperty = resolveProperty( prevProp );
+					const StyleSheetProperty* curProperty = resolvedPrevProperty.get();
 					if ( propertyDefinition->isIndexed() &&
 						 property->getIndex() < curProperty->getPropertyIndexCount() ) {
-						StyleSheetProperty* indexedProperty =
-							curProperty->getPropertyIndexRef( property->getIndex() );
-						applyVarValues( indexedProperty );
-						startValue = indexedProperty->getValue();
+						startValue =
+							curProperty->getPropertyIndex( property->getIndex() ).getValue();
 					} else {
-						applyVarValues( curProperty );
 						startValue = curProperty->getValue();
 					}
 				}
@@ -746,24 +747,26 @@ void UIStyle::updateAnimations() {
 	if ( nullptr == mDefinition )
 		return;
 
-	bool isDifferent = false;
-	CSS::AnimationsMap animations;
-
-	if ( !mDefinition->getAnimationProperties().empty() ) {
-		animations =
-			AnimationDefinition::parseAnimationProperties( mDefinition->getAnimationProperties() );
-		if ( animations.size() == mAnimations.size() ) {
-			for ( auto& animation : animations ) {
-				auto animIt = mAnimations.find( animation.second.getName() );
-				if ( animIt == mAnimations.end() || animIt->second != animation.second ) {
-					isDifferent = true;
-					break;
-				}
-			}
-		} else {
-			isDifferent = true;
+	if ( mDefinition->getAnimationProperties().empty() ) {
+		if ( !mAnimations.empty() ) {
+			mAnimations.clear();
+			removeAllAnimations();
 		}
-	} else if ( !mAnimations.empty() && mDefinition->getAnimationProperties().empty() ) {
+		return;
+	}
+
+	bool isDifferent = false;
+	CSS::AnimationsMap animations =
+		AnimationDefinition::parseAnimationProperties( mDefinition->getAnimationProperties() );
+	if ( animations.size() == mAnimations.size() ) {
+		for ( auto& animation : animations ) {
+			auto animIt = mAnimations.find( animation.second.getName() );
+			if ( animIt == mAnimations.end() || animIt->second != animation.second ) {
+				isDifferent = true;
+				break;
+			}
+		}
+	} else {
 		isDifferent = true;
 	}
 
@@ -773,7 +776,7 @@ void UIStyle::updateAnimations() {
 		removeAllAnimations();
 
 		startAnimations( animations );
-	} else if ( !mDefinition->getAnimationProperties().empty() ) {
+	} else {
 		updateAnimationsPlayState();
 	}
 }
@@ -944,16 +947,25 @@ StyleSheetProperty* UIStyle::getLocalProperty( PropertyId propId ) {
 	return defProperty ? defProperty : elemProperty;
 }
 
-StyleSheetProperty*
-UIStyle::getResolvedLocalProperty( PropertyId propId,
-								   std::optional<StyleSheetProperty>& resolvedProperty ) {
-	StyleSheetProperty* property = getLocalProperty( propId );
-	if ( property && property->needsValueSubstitution() ) {
-		resolvedProperty.emplace( *property );
-		applyVarValues( &*resolvedProperty );
-		return &*resolvedProperty;
-	}
-	return property;
+UIStyle::PropertyResolution UIStyle::resolveProperty( const StyleSheetProperty* property ) {
+	if ( nullptr == property || !property->needsValueSubstitution() )
+		return PropertyResolution{ nullptr, property };
+
+	const Uint32 slotIndex = mPropertyResolutionDepth;
+	if ( slotIndex >= mPropertyResolutionSlots.size() )
+		mPropertyResolutionSlots.emplace_back( std::make_unique<StyleSheetProperty>() );
+	StyleSheetProperty* slot = mPropertyResolutionSlots[slotIndex].get();
+
+	++mPropertyResolutionDepth;
+	PropertyResolution resolution{ this, slot, slotIndex };
+	if ( !slot->hasSameResolutionSource( *property ) )
+		*slot = *property;
+	applyVarValues( slot );
+	return resolution;
+}
+
+UIStyle::PropertyResolution UIStyle::getResolvedLocalProperty( PropertyId propId ) {
+	return resolveProperty( getLocalProperty( propId ) );
 }
 
 void UIStyle::addStructurallyVolatileWidgetFromParent() {
diff --git a/src/eepp/ui/uiwidget.cpp b/src/eepp/ui/uiwidget.cpp
index a41759236..5028d9326 100644
--- a/src/eepp/ui/uiwidget.cpp
+++ b/src/eepp/ui/uiwidget.cpp
@@ -18,6 +18,7 @@
 #include <eepp/ui/uiwidget.hpp>
 #include <eepp/window/engine.hpp>
 #include <eepp/window/window.hpp>
+#include <optional>
 
 #define PUGIXML_HEADER_ONLY
 #include <pugixml/pugixml.hpp>
@@ -1994,14 +1995,18 @@ void UIWidget::setStyleSheetInlineProperty( const std::string& name, const std::
 }
 
 void UIWidget::propagateInheritedProperty( const CSS::StyleSheetProperty& property ) {
-	CSS::StyleSheetProperty propToPropagate = property;
+	const CSS::StyleSheetProperty* propertyToPropagate = &property;
+	std::optional<CSS::StyleSheetProperty> resolvedProperty;
 
-	if ( propToPropagate.needsValueSubstitution() && NULL != mStyle )
-		mStyle->applyVarValues( &propToPropagate );
+	if ( property.needsValueSubstitution() && NULL != mStyle ) {
+		resolvedProperty.emplace( property );
+		mStyle->applyVarValues( &*resolvedProperty );
+		propertyToPropagate = &*resolvedProperty;
+	}
 
-	if ( propToPropagate.getPropertyDefinition() &&
-		 propToPropagate.getPropertyDefinition()->getPropertyId() == PropertyId::FontSize ) {
-		StyleSheetLength length( propToPropagate.value() );
+	if ( propertyToPropagate->getPropertyDefinition() &&
+		 propertyToPropagate->getPropertyDefinition()->getPropertyId() == PropertyId::FontSize ) {
+		StyleSheetLength length( propertyToPropagate->value() );
 		Float pxSize = 0;
 
 		if ( length.getUnit() == StyleSheetLength::Unit::Rem ) {
@@ -2029,14 +2034,23 @@ void UIWidget::propagateInheritedProperty( const CSS::StyleSheetProperty& proper
 			else
 				pxSize = ( length.getValue() / 100.f ) * parentFontSize;
 		} else {
-			pxSize = lengthFromValue( propToPropagate );
+			pxSize = lengthFromValue( *propertyToPropagate );
 		}
 
-		propToPropagate = CSS::StyleSheetProperty(
-			propToPropagate.getName(), String::fromFloat( PixelDensity::pxToDp( pxSize ), "dp" ),
-			propToPropagate.getSpecificity() );
+		const PropertyDefinition* propertyDefinition = propertyToPropagate->getPropertyDefinition();
+		const Uint32 propertyIndex = propertyToPropagate->getIndex();
+		const Int64 specificity = propertyToPropagate->getSpecificity();
+		resolvedProperty.emplace( propertyDefinition,
+								  String::fromFloat( PixelDensity::pxToDp( pxSize ), "dp" ),
+								  propertyIndex );
+		resolvedProperty->setSpecificity( specificity );
+		propertyToPropagate = &*resolvedProperty;
 	}
 
+	propagateInheritedPropertyResolved( *propertyToPropagate );
+}
+
+void UIWidget::propagateInheritedPropertyResolved( const CSS::StyleSheetProperty& property ) {
 	Node* child = getFirstChild();
 	while ( child ) {
 		if ( child->isWidget() ) {
@@ -2044,9 +2058,9 @@ void UIWidget::propagateInheritedProperty( const CSS::StyleSheetProperty& proper
 			UIStyle* childStyle = childWidget->getUIStyle();
 			// Only propagate if the child doesn't explicitly override it
 			if ( childStyle && !childStyle->hasLocalProperty(
-								   propToPropagate.getPropertyDefinition()->getPropertyId() ) ) {
-				childWidget->applyProperty( propToPropagate );
-				childWidget->propagateInheritedProperty( propToPropagate );
+								   property.getPropertyDefinition()->getPropertyId() ) ) {
+				childWidget->applyProperty( property );
+				childWidget->propagateInheritedPropertyResolved( property );
 			}
 		}
 		child = child->getNextNode();
diff --git a/src/tests/unit_tests/action_transition_tests.cpp b/src/tests/unit_tests/action_transition_tests.cpp
index 4624f56a3..905a8ed4c 100644
--- a/src/tests/unit_tests/action_transition_tests.cpp
+++ b/src/tests/unit_tests/action_transition_tests.cpp
@@ -1,6 +1,7 @@
 #include "utest.h"
 #include <eepp/scene/actions/delay.hpp>
 #include <eepp/scene/actions/runnable.hpp>
+#include <eepp/ui/css/animationdefinition.hpp>
 #include <eepp/ui/css/stylesheetspecification.hpp>
 #include <eepp/ui/css/transitiondefinition.hpp>
 
@@ -123,3 +124,57 @@ UTEST( Transitions, allocationLightParserPreservesAcceptedSpelling ) {
 	EXPECT_EQ( opacity->timingFunctionParameters.size(), 4u );
 	EXPECT_TRUE( TimingFunction::parse( "cubic-bezier(" ).interpolation == Ease::None );
 }
+
+UTEST( Animations, allocationLightShorthandPreservesSemantics ) {
+	auto* specification = StyleSheetSpecification::instance();
+	StyleSheetProperty shorthand(
+		specification->getProperty( PropertyId::Animation ),
+		"fade +150MS CUBIC-BEZIER(0.1, 0.2, 0.3, 0.4) +25MS 3 alternate both paused, "
+		"slide 2s linear" );
+	std::vector<const StyleSheetProperty*> properties{ &shorthand };
+
+	AnimationsMap animations = AnimationDefinition::parseAnimationProperties( properties );
+	auto fade = animations.find( "fade" );
+	auto slide = animations.find( "slide" );
+	ASSERT_TRUE( fade != animations.end() );
+	ASSERT_TRUE( slide != animations.end() );
+	EXPECT_EQ( fade->second.getDuration().asMilliseconds(), 150.0 );
+	EXPECT_EQ( fade->second.getDelay().asMilliseconds(), 25.0 );
+	EXPECT_EQ( fade->second.getIterations(), 3 );
+	EXPECT_TRUE( fade->second.getDirection() == AnimationDefinition::Alternate );
+	EXPECT_TRUE( fade->second.getFillMode() == AnimationDefinition::Both );
+	EXPECT_TRUE( fade->second.isPaused() );
+	EXPECT_TRUE( fade->second.getTimingFunction() == Ease::CubizBezier );
+	EXPECT_EQ( fade->second.getTimingFunctionParametersInline().size(), 4u );
+	EXPECT_EQ( slide->second.getDuration().asSeconds(), 2.0 );
+	EXPECT_EQ( slide->second.getDelay().asSeconds(), 0.0 );
+}
+
+UTEST( Animations, allocationLightLonghandListsCycleIndependently ) {
+	auto* specification = StyleSheetSpecification::instance();
+	StyleSheetProperty names( specification->getProperty( PropertyId::AnimationName ),
+							  "first,second,third" );
+	StyleSheetProperty durations( specification->getProperty( PropertyId::AnimationDuration ),
+								  "1s,2s" );
+	StyleSheetProperty delays( specification->getProperty( PropertyId::AnimationDelay ),
+							   "10ms,20ms" );
+	StyleSheetProperty directions( specification->getProperty( PropertyId::AnimationDirection ),
+								   "reverse,alternate" );
+	StyleSheetProperty timing( specification->getProperty( PropertyId::AnimationTimingFunction ),
+							   "linear,cubic-bezier(0.1, 0.2, 0.3, 0.4)" );
+	std::vector<const StyleSheetProperty*> properties{ &names, &durations, &delays, &directions,
+													   &timing };
+
+	AnimationsMap animations = AnimationDefinition::parseAnimationProperties( properties );
+	ASSERT_EQ( animations.size(), 3u );
+	EXPECT_EQ( animations.at( "first" ).getDuration().asSeconds(), 1.0 );
+	EXPECT_EQ( animations.at( "second" ).getDuration().asSeconds(), 2.0 );
+	EXPECT_EQ( animations.at( "third" ).getDuration().asSeconds(), 1.0 );
+	EXPECT_EQ( animations.at( "third" ).getDelay().asMilliseconds(), 10.0 );
+	EXPECT_TRUE( animations.at( "first" ).getDirection() == AnimationDefinition::Reverse );
+	EXPECT_TRUE( animations.at( "second" ).getDirection() == AnimationDefinition::Alternate );
+	EXPECT_TRUE( animations.at( "third" ).getDirection() == AnimationDefinition::Reverse );
+	EXPECT_TRUE( animations.at( "first" ).getTimingFunction() == Ease::Linear );
+	EXPECT_TRUE( animations.at( "second" ).getTimingFunction() == Ease::CubizBezier );
+	EXPECT_EQ( animations.at( "second" ).getTimingFunctionParametersInline().size(), 4u );
+}
diff --git a/src/tests/unit_tests/color_parsing_tests.cpp b/src/tests/unit_tests/color_parsing_tests.cpp
index 4b0bf4279..f0d758cb7 100644
--- a/src/tests/unit_tests/color_parsing_tests.cpp
+++ b/src/tests/unit_tests/color_parsing_tests.cpp
@@ -280,3 +280,10 @@ UTEST( ColorParsing, hsvaWithThreeLegacy ) {
 	EXPECT_COLOREQ( Color( 255, 0, 0, 255 ),
 					Color::fromString( "hsva(0, 100%, 100%)" ) );
 }
+
+UTEST( ColorParsing, hexSerialization ) {
+	EXPECT_STDSTREQ( "#01020f", Color( 1, 2, 15 ).toHexString() );
+	EXPECT_STDSTREQ( "01020f", Color( 1, 2, 15 ).toHexString( false ) );
+	EXPECT_STDSTREQ( "#01020f10", Color( 1, 2, 15, 16 ).toHexString() );
+	EXPECT_STDSTREQ( "01020f10", Color( 1, 2, 15, 16 ).toHexString( false ) );
+}
diff --git a/src/tests/unit_tests/uicss_inheritance_tests.cpp b/src/tests/unit_tests/uicss_inheritance_tests.cpp
index 992ea93ff..63b8c63dd 100644
--- a/src/tests/unit_tests/uicss_inheritance_tests.cpp
+++ b/src/tests/unit_tests/uicss_inheritance_tests.cpp
@@ -31,6 +31,44 @@ using namespace EE::UI::CSS;
 using namespace EE::Scene;
 using namespace EE::Graphics;
 
+namespace {
+
+class ResolutionStorageTestStyle : public UIStyle {
+  public:
+	ResolutionStorageTestStyle() : UIStyle( nullptr ) {}
+
+	struct Probe {
+		const StyleSheetProperty* firstAddress{};
+		const StyleSheetProperty* nestedAddress{};
+		const StyleSheetProperty* reusedAddress{};
+		std::string firstValueBeforeNested;
+		std::string firstValueAfterNested;
+		std::string nestedValue;
+	};
+
+	Probe probe( const StyleSheetProperty& first, const StyleSheetProperty& nested ) {
+		Probe probe;
+		{
+			auto firstResolution = resolveProperty( &first );
+			probe.firstAddress = firstResolution.get();
+			probe.firstValueBeforeNested = firstResolution.get()->getValue();
+			{
+				auto nestedResolution = resolveProperty( &nested );
+				probe.nestedAddress = nestedResolution.get();
+				probe.nestedValue = nestedResolution.get()->getValue();
+			}
+			probe.firstValueAfterNested = firstResolution.get()->getValue();
+		}
+		{
+			auto reusedResolution = resolveProperty( &first );
+			probe.reusedAddress = reusedResolution.get();
+		}
+		return probe;
+	}
+};
+
+} // namespace
+
 UTEST( CSSParser, UnknownPropertiesKeepDistinctNameHashes ) {
 	StyleSheetProperty first( "data-first", "one" );
 	StyleSheetProperty second( "data-second", "two" );
@@ -44,6 +82,17 @@ UTEST( CSSParser, UnknownPropertiesKeepDistinctNameHashes ) {
 	EXPECT_TRUE( first.getShorthandId() == ShorthandId::Invalid );
 }
 
+UTEST( CSSParser, DefinitionBackedPropertiesUseCanonicalDefinitionName ) {
+	auto* definition =
+		StyleSheetSpecification::instance()->getProperty( PropertyId::BackgroundColor );
+	ASSERT_TRUE( nullptr != definition );
+	StyleSheetProperty property( definition, "#010203" );
+
+	EXPECT_FALSE( property.isEmpty() );
+	EXPECT_STDSTREQ( definition->getName(), property.getName() );
+	EXPECT_EQ( definition->getId(), property.getNameHash() );
+}
+
 UTEST( CSSParser, CommentsPreserveDeclarationContext ) {
 	StyleSheetPropertiesParser parser( R"css(
 		color /* before colon */ : red;
@@ -487,6 +536,40 @@ UTEST( CSSVariables, StyleSheetPropertyNeedsValueSubstitution ) {
 					  .needsValueSubstitution() );
 }
 
+UTEST( CSSVariables, ResolutionStorageIsReentrantAndReusable ) {
+	ResolutionStorageTestStyle style;
+	style.setStyleSheetVariable( StyleSheetVariable( "--first", "#123456" ) );
+	style.setStyleSheetVariable( StyleSheetVariable( "--nested", "#ABCDEF" ) );
+
+	const auto probe = style.probe( StyleSheetProperty( "color", "var(--first)" ),
+									StyleSheetProperty( "background-color", "var(--nested)" ) );
+
+	EXPECT_TRUE( nullptr != probe.firstAddress );
+	EXPECT_TRUE( nullptr != probe.nestedAddress );
+	EXPECT_NE( probe.firstAddress, probe.nestedAddress );
+	EXPECT_EQ( probe.firstAddress, probe.reusedAddress );
+	EXPECT_STDSTREQ( "#123456", probe.firstValueBeforeNested );
+	EXPECT_STDSTREQ( "#123456", probe.firstValueAfterNested );
+	EXPECT_STDSTREQ( "#ABCDEF", probe.nestedValue );
+}
+
+UTEST( CSSVariables, StyleSheetPropertyReusesVariableCacheStorage ) {
+	StyleSheetProperty property( "color", "var(--a-variable-name-long-enough-to-allocate)" );
+	auto firstCache = property.getVarCache();
+	ASSERT_EQ( 1u, firstCache.size() );
+	const auto* cacheAddress = &*firstCache.begin();
+	const auto* variableStorage = firstCache.begin()->variableList.data();
+
+	property.setValue( "#123456" );
+	EXPECT_TRUE( property.getVarCache().empty() );
+
+	property.setValue( "var(--a-variable-name-long-enough-to-allocate)" );
+	auto reusedCache = property.getVarCache();
+	ASSERT_EQ( 1u, reusedCache.size() );
+	EXPECT_EQ( cacheAddress, &*reusedCache.begin() );
+	EXPECT_EQ( variableStorage, reusedCache.begin()->variableList.data() );
+}
+
 UTEST( CSSVariables, StyleAttributeVarOnRichTextAndTextSpan ) {
 	UIApplication app(
 		WindowSettings( 800, 600, "eepp - CSS Style Attribute Var Test", WindowStyle::Default,
diff --git a/src/tools/eeiv/eeiv.cpp b/src/tools/eeiv/eeiv.cpp
index 80cd5c6af..a8fb1affb 100644
--- a/src/tools/eeiv/eeiv.cpp
+++ b/src/tools/eeiv/eeiv.cpp
@@ -281,8 +281,10 @@ bool App::init() {
 	mConsole->setMaxLogLines( 1024000 );
 	mConsole->setFontSize( mConfig.ConsoleFontSize );
 	mConsole->on( Event::KeyDown, [this]( const Event* event ) {
-		if ( event->asKeyEvent()->getKeyCode() == KEY_ESCAPE )
+		if ( event->asKeyEvent()->getKeyCode() == KEY_ESCAPE ) {
+			saveConfig();
 			mUIApplication->getWindow()->close();
+		}
 	} );
 	mConsoleCommands = std::make_unique<ConsoleCommands>( this, mConsole );
 	registerConsoleCommands();
@@ -357,9 +359,10 @@ void App::registerKeyBindings() {
 		}
 		if ( mConsole->isActive() )
 			return;
-		if ( key == KEY_ESCAPE || key == KEY_Q )
+		if ( key == KEY_ESCAPE || key == KEY_Q ) {
+			saveConfig();
 			getWindow()->close();
-		else if ( key == KEY_TAB && keyEvent->getMod() & KEYMOD_ALT )
+		} else if ( key == KEY_TAB && keyEvent->getMod() & KEYMOD_ALT )
 			getWindow()->minimize();
 		else if ( key == KEY_F || ( key == KEY_RETURN && keyEvent->getMod() & KEYMOD_ALT ) )
 			getWindow()->toggleFullscreen();