diff --git a/include/eepp/ui/css/stylesheet.hpp b/include/eepp/ui/css/stylesheet.hpp
index f0b6c68e9..9146e01bf 100644
--- a/include/eepp/ui/css/stylesheet.hpp
+++ b/include/eepp/ui/css/stylesheet.hpp
@@ -13,6 +13,8 @@ class EE_API StyleSheet {
   public:
 	StyleSheet();
 
+	void clear();
+
 	void addStyle( std::shared_ptr<StyleSheetStyle> node );
 
 	bool isEmpty() const;
@@ -54,6 +56,8 @@ class EE_API StyleSheet {
 
 	bool markerExists( const Uint32& marker ) const;
 
+	StyleSheet getAllWithMarker( const Uint32& marker ) const;
+
 	std::vector<std::shared_ptr<StyleSheetStyle>>
 	findStyleFromSelectorName( const std::string& selector ) const;
 
diff --git a/include/eepp/ui/css/stylesheetparser.hpp b/include/eepp/ui/css/stylesheetparser.hpp
index 013d7d1d1..ce4a17134 100644
--- a/include/eepp/ui/css/stylesheetparser.hpp
+++ b/include/eepp/ui/css/stylesheetparser.hpp
@@ -6,8 +6,6 @@
 #include <eepp/ui/css/mediaquery.hpp>
 #include <eepp/ui/css/stylesheet.hpp>
 #include <eepp/ui/css/stylesheetpropertiesparser.hpp>
-#include <iostream>
-#include <map>
 #include <string>
 using namespace EE;
 using namespace EE::System;
@@ -32,6 +30,8 @@ class EE_API StyleSheetParser {
 
 	bool loadFromString( const std::string& str );
 
+	bool loadFromString( const std::string_view& str );
+
 	void print();
 
 	StyleSheet& getStyleSheet();
diff --git a/include/eepp/ui/uiscenenode.hpp b/include/eepp/ui/uiscenenode.hpp
index d5aa068ca..cc928ae88 100644
--- a/include/eepp/ui/uiscenenode.hpp
+++ b/include/eepp/ui/uiscenenode.hpp
@@ -13,6 +13,7 @@ class Font;
 
 namespace EE { namespace UI {
 
+class UITheme;
 class UIThemeManager;
 class UIIconThemeManager;
 class UIEventDispatcher;
@@ -86,7 +87,7 @@ class EE_API UISceneNode : public SceneNode {
 							const bool& forceReloadStyle = true );
 
 	void combineStyleSheet( const std::string& inlineStyleSheet,
-							const bool& forceReloadStyle = true );
+							const bool& forceReloadStyle = true, const Uint32& marker = 0 );
 
 	CSS::StyleSheet& getStyleSheet();
 
@@ -167,6 +168,8 @@ class EE_API UISceneNode : public SceneNode {
 
 	void setThreadPool( const std::shared_ptr<ThreadPool>& threadPool );
 
+	void setTheme( UITheme* theme );
+
   protected:
 	friend class EE::UI::UIWindow;
 	friend class EE::UI::UIWidget;
@@ -240,6 +243,8 @@ class EE_API UISceneNode : public SceneNode {
 	CSS::MediaFeatures getMediaFeatures() const;
 
 	std::vector<UIWidget*> loadNode( pugi::xml_node node, Node* parent, const Uint32& marker );
+
+	void setTheme( UITheme* theme, Node* to );
 };
 
 }} // namespace EE::UI
diff --git a/src/eepp/ui/css/stylesheet.cpp b/src/eepp/ui/css/stylesheet.cpp
index fc9841ee9..0cfd3734b 100644
--- a/src/eepp/ui/css/stylesheet.cpp
+++ b/src/eepp/ui/css/stylesheet.cpp
@@ -9,6 +9,16 @@ namespace EE { namespace UI { namespace CSS {
 
 StyleSheet::StyleSheet() {}
 
+void StyleSheet::clear() {
+	mVersion = 1;
+	mMarker = 0;
+	mNodes.clear();
+	mNodeIndex.clear();
+	mMediaQueryList.clear();
+	mKeyframesMap.clear();
+	mNodeCache.clear();
+}
+
 template <class T> inline void HashCombine( std::size_t& seed, const T& v ) {
 	std::hash<T> hasher;
 	seed ^= hasher( v ) + 0x9e3779b9 + ( seed << 6 ) + ( seed >> 2 );
@@ -98,6 +108,16 @@ void StyleSheet::removeAllWithMarker( const Uint32& marker ) {
 	invalidateCache();
 }
 
+StyleSheet StyleSheet::getAllWithMarker( const Uint32& marker ) const {
+	StyleSheet style;
+	std::vector<std::shared_ptr<StyleSheetStyle>> hits;
+	for ( auto node : mNodes ) {
+		if ( node->getMarker() == marker )
+			style.addStyle( node );
+	}
+	return style;
+}
+
 bool StyleSheet::markerExists( const Uint32& marker ) const {
 	for ( auto node : mNodes ) {
 		if ( node->getMarker() == marker )
diff --git a/src/eepp/ui/css/stylesheetparser.cpp b/src/eepp/ui/css/stylesheetparser.cpp
index 133e558f1..c0689ab4f 100644
--- a/src/eepp/ui/css/stylesheetparser.cpp
+++ b/src/eepp/ui/css/stylesheetparser.cpp
@@ -14,6 +14,7 @@
 #include <eepp/ui/css/stylesheetparser.hpp>
 #include <eepp/ui/css/stylesheetpropertiesparser.hpp>
 #include <eepp/ui/css/stylesheetselectorparser.hpp>
+#include <iostream>
 
 using namespace EE::Network;
 using namespace EE::System;
@@ -87,6 +88,13 @@ bool StyleSheetParser::loadFromString( const std::string& str ) {
 	return loadFromMemory( (const Uint8*)&str[0], str.size() );
 }
 
+bool StyleSheetParser::loadFromString( const std::string_view& str ) {
+	if ( str.empty() )
+		return false;
+
+	return loadFromMemory( (const Uint8*)str.data(), str.size() );
+}
+
 StyleSheet& StyleSheetParser::getStyleSheet() {
 	return mStyleSheet;
 }
diff --git a/src/eepp/ui/tools/uicolorpicker.cpp b/src/eepp/ui/tools/uicolorpicker.cpp
index db726f7a2..f3805146b 100644
--- a/src/eepp/ui/tools/uicolorpicker.cpp
+++ b/src/eepp/ui/tools/uicolorpicker.cpp
@@ -231,7 +231,7 @@ UIColorPicker::UIColorPicker( UIWindow* attachTo, const UIColorPicker::ColorPick
 		UISceneNode* uiSceneNode = mUIContainer->getSceneNode()->asType<UISceneNode>();
 
 		if ( !sStyleSheetParser.isLoaded() ) {
-			sStyleSheetParser.loadFromString( std::string( COLOR_PICKER_STYLE ) );
+			sStyleSheetParser.loadFromString( std::string_view{ COLOR_PICKER_STYLE } );
 		}
 
 		if ( sLastSceneNode != uiSceneNode ) {
diff --git a/src/eepp/ui/uiscenenode.cpp b/src/eepp/ui/uiscenenode.cpp
index 975bdf1a7..782fbaac3 100644
--- a/src/eepp/ui/uiscenenode.cpp
+++ b/src/eepp/ui/uiscenenode.cpp
@@ -304,7 +304,7 @@ std::vector<UIWidget*> UISceneNode::loadNode( pugi::xml_node node, Node* parent,
 		} else if ( String::toLower( std::string( widget.name() ) ) == "style" ) {
 			CSS::StyleSheetParser parser;
 
-			if ( parser.loadFromString( widget.text().as_string() ) ) {
+			if ( parser.loadFromString( std::string_view{ widget.text().as_string() } ) ) {
 				parser.getStyleSheet().setMarker( marker );
 				combineStyleSheet( parser.getStyleSheet(), false );
 			}
@@ -383,11 +383,14 @@ void UISceneNode::combineStyleSheet( const CSS::StyleSheet& styleSheet,
 }
 
 void UISceneNode::combineStyleSheet( const std::string& inlineStyleSheet,
-									 const bool& forceReloadStyle ) {
+									 const bool& forceReloadStyle, const Uint32& marker ) {
 	CSS::StyleSheetParser parser;
 
-	if ( parser.loadFromString( inlineStyleSheet ) )
+	if ( parser.loadFromString( inlineStyleSheet ) ) {
+		parser.getStyleSheet().setMarker( marker );
+
 		combineStyleSheet( parser.getStyleSheet(), forceReloadStyle );
+	}
 }
 
 CSS::StyleSheet& UISceneNode::getStyleSheet() {
@@ -652,6 +655,18 @@ UIThemeManager* UISceneNode::getUIThemeManager() const {
 	return mUIThemeManager;
 }
 
+void UISceneNode::setTheme( UITheme* theme ) {
+	setTheme( theme, mRoot );
+}
+
+void UISceneNode::setTheme( UITheme* theme, Node* to ) {
+	to->forEachChild( [theme, this]( Node* node ) {
+		if ( node->isWidget() )
+			node->asType<UIWidget>()->setTheme( theme );
+		setTheme( theme, node );
+	} );
+}
+
 UIWidget* UISceneNode::getRoot() const {
 	return mRoot;
 }
diff --git a/src/examples/http_request/http_request.cpp b/src/examples/http_request/http_request.cpp
index ed5fc1fc9..3515eedff 100644
--- a/src/examples/http_request/http_request.cpp
+++ b/src/examples/http_request/http_request.cpp
@@ -1,5 +1,6 @@
 #include <args/args.hxx>
 #include <eepp/ee.hpp>
+#include <iostream>
 
 // Prints the response headers
 void printResponseHeaders( Http::Response& response ) {
diff --git a/src/tools/ecode/ecode.cpp b/src/tools/ecode/ecode.cpp
index 0d8e91767..fe894fcbf 100644
--- a/src/tools/ecode/ecode.cpp
+++ b/src/tools/ecode/ecode.cpp
@@ -44,6 +44,8 @@ bool firstFrame = true;
 bool firstUpdate = true;
 App* appInstance = nullptr;
 
+static const Uint32 APP_LAYOUT_STYLE_MARKER = String::hash( "app_layout_style" );
+
 void appLoop() {
 	appInstance->mainLoop();
 }
@@ -1779,6 +1781,10 @@ void App::setTheme( const std::string& path ) {
 	}
 
 	mUISceneNode->setStyleSheet( theme->getStyleSheet() );
+
+	if ( !mAppStyleSheet.isEmpty() )
+		mUISceneNode->getStyleSheet().combineStyleSheet( mAppStyleSheet );
+
 	mUISceneNode
 		->getUIThemeManager()
 		//->setDefaultEffectsEnabled( true )
@@ -1787,6 +1793,8 @@ void App::setTheme( const std::string& path ) {
 		->setDefaultFontSize( mConfig.ui.fontSize.asPixels( 0, Sizef(), mDisplayDPI ) )
 		->add( theme );
 
+	mUISceneNode->setTheme( theme );
+
 	mUISceneNode->getRoot()->addClass( "appbackground" );
 
 	if ( mTheme )
@@ -3490,7 +3498,7 @@ void App::init( const LogLevel& logLevel, std::string file, const Float& pidelDe
 		}
 		)css",
 											 mConfig.ui.panelFontSize.toString().c_str() ) );
-		mUISceneNode->combineStyleSheet( panelUI, false );
+		mUISceneNode->combineStyleSheet( panelUI, false, APP_LAYOUT_STYLE_MARKER );
 
 		const auto baseUI = (
 #include "applayout.xml.hpp"
@@ -3510,7 +3518,8 @@ void App::init( const LogLevel& logLevel, std::string file, const Float& pidelDe
 		UIWidgetCreator::registerWidget( "mainlayout", UIMainLayout::New );
 		UIWidgetCreator::registerWidget( "statusbar", UIStatusBar::New );
 		UIWidgetCreator::registerWidget( "rellayce", UIRelativeLayoutCommandExecuter::New );
-		mUISceneNode->loadLayoutFromString( baseUI );
+		mUISceneNode->loadLayoutFromString( baseUI, nullptr, APP_LAYOUT_STYLE_MARKER );
+		mAppStyleSheet = mUISceneNode->getStyleSheet().getAllWithMarker( APP_LAYOUT_STYLE_MARKER );
 		mUISceneNode->bind( "main_layout", mMainLayout );
 		mUISceneNode->bind( "code_container", mBaseLayout );
 		mUISceneNode->bind( "image_container", mImageLayout );
diff --git a/src/tools/ecode/ecode.hpp b/src/tools/ecode/ecode.hpp
index c9c281e37..6ad19b2a6 100644
--- a/src/tools/ecode/ecode.hpp
+++ b/src/tools/ecode/ecode.hpp
@@ -512,6 +512,7 @@ class App : public UICodeEditorSplitter::Client {
 	UITheme* mTheme{ nullptr };
 	UIStatusBar* mStatusBar{ nullptr };
 	UISplitter* mMainSplitter{ nullptr };
+	StyleSheet mAppStyleSheet;
 
 	void saveAllProcess();
 
diff --git a/src/tools/eterm/eterm.cpp b/src/tools/eterm/eterm.cpp
index e87b7fd4a..1e3b5e926 100644
--- a/src/tools/eterm/eterm.cpp
+++ b/src/tools/eterm/eterm.cpp
@@ -1,6 +1,7 @@
 #include <args/args.hxx>
 #include <eepp/ee.hpp>
 #include <eterm/terminal/terminaldisplay.hpp>
+#include <iostream>
 
 EE::Window::Window* win = NULL;
 std::shared_ptr<TerminalDisplay> terminal = nullptr;
diff --git a/src/tools/uieditor/uieditor.cpp b/src/tools/uieditor/uieditor.cpp
index 4048801f8..7fd8b4a76 100644
--- a/src/tools/uieditor/uieditor.cpp
+++ b/src/tools/uieditor/uieditor.cpp
@@ -1,6 +1,7 @@
 #include "uieditor.hpp"
 #include <args/args.hxx>
 #define PUGIXML_HEADER_ONLY
+#include <iostream>
 #include <pugixml/pugixml.hpp>
 
 namespace uieditor {