diff --git a/assets/fonts/fontawesome/fa7_brands_regular_400.otf b/assets/fonts/fontawesome/fa7_brands_regular_400.otf
new file mode 100644
index 0000000..dc9a6df
Binary files /dev/null and b/assets/fonts/fontawesome/fa7_brands_regular_400.otf differ
diff --git a/assets/fonts/fontawesome/fa7_free_regular_400.otf b/assets/fonts/fontawesome/fa7_free_regular_400.otf
new file mode 100644
index 0000000..bdaae48
Binary files /dev/null and b/assets/fonts/fontawesome/fa7_free_regular_400.otf differ
diff --git a/assets/fonts/fontawesome/fa7_freesolid_900.otf b/assets/fonts/fontawesome/fa7_freesolid_900.otf
new file mode 100644
index 0000000..881f5d3
Binary files /dev/null and b/assets/fonts/fontawesome/fa7_freesolid_900.otf differ
diff --git a/examples/windows_app_example.php b/examples/windows_app_example.php
index 6b2ad6f..82c968b 100644
--- a/examples/windows_app_example.php
+++ b/examples/windows_app_example.php
@@ -3,21 +3,80 @@
 require_once __DIR__ . '/../vendor/autoload.php';
 
 use PHPNative\Framework\Application;
+use PHPNative\Framework\IconFontRegistry;
+use PHPNative\Tailwind\Data\Icon as IconName;
+use PHPNative\Ui\Widget\Button;
 use PHPNative\Ui\Widget\Container;
+use PHPNative\Ui\Widget\Icon;
 use PHPNative\Ui\Widget\Label;
 use PHPNative\Ui\Widget\Menu;
 use PHPNative\Ui\Widget\MenuBar;
+use PHPNative\Ui\Widget\Modal;
 use PHPNative\Ui\Widget\StatusBar;
 use PHPNative\Ui\Widget\TabContainer;
 use PHPNative\Ui\Widget\Table;
+use PHPNative\Ui\Widget\TextInput;
 use PHPNative\Ui\Window;
 
+$iconFontCandidates = [
+    __DIR__ . '/../assets/fonts/fa-solid-900.ttf',
+    __DIR__ . '/../assets/fonts/fontawesome/fa7_freesolid_900.otf',
+    '/usr/share/fonts/truetype/fontawesome-webfont.ttf',
+    '/usr/share/fonts/truetype/fontawesome/fa-solid-900.ttf',
+    '/usr/share/fonts/truetype/fa-solid-900.ttf',
+];
+
+$iconFontPath = null;
+foreach ($iconFontCandidates as $candidate) {
+    if (is_file($candidate)) {
+        $iconFontPath = $candidate;
+        break;
+    }
+}
+
+if ($iconFontPath !== null) {
+    IconFontRegistry::setDefaultFontPath($iconFontPath);
+} else {
+    echo "Hinweis: FontAwesome Font nicht gefunden. Icons werden ohne Symbol dargestellt.\n";
+}
+
 $app = new Application();
 $window = new Window('Windows Application Example', 800, 600);
+$currentApiKey = '';
+
+/** @var Label|null $statusLabel */
+$statusLabel = null;
 
 // Main container (flex-col: menu, content, status)
 $mainContainer = new Container('flex flex-col bg-gray-100');
 
+// Modal dialog setup (hidden by default)
+$apiKeyInput = new TextInput('API Key', 'w-full border border-gray-300 rounded px-3 py-2 bg-white text-black');
+
+$modalDialog = new Container('bg-white border border-gray-300 rounded p-6 flex flex-col w-96 gap-3 shadow-lg');
+$modalDialog->addComponent(new Label('API Einstellungen', 'text-xl font-bold text-black'));
+$modalDialog->addComponent(new Label(
+    'Bitte gib deinen API Key ein, um externe Dienste zu verbinden.',
+    'text-sm text-gray-700',
+));
+
+$fieldContainer = new Container('flex flex-col gap-1');
+$fieldContainer->addComponent(new Label('API Key', 'text-sm text-gray-600'));
+$fieldContainer->addComponent($apiKeyInput);
+$modalDialog->addComponent($fieldContainer);
+
+$buttonRow = new Container('flex flex-row justify-end gap-2');
+$cancelButton = new Button('Abbrechen', 'px-4 py-2 bg-gray-200 text-black rounded hover:bg-gray-300');
+$saveButton = new Button('Speichern', 'px-4 py-2 bg-blue-600 text-white rounded hover:bg-blue-700 flex items-center');
+$saveIcon = new Icon(IconName::save, 18, 'text-white');
+$saveButton->setIcon($saveIcon);
+$buttonRow->addComponent($cancelButton);
+$buttonRow->addComponent($saveButton);
+$modalDialog->addComponent($buttonRow);
+
+$modal = new Modal($modalDialog);
+$modal->setBackdropAlpha(180);
+
 // === 1. MenuBar ===
 $menuBar = new MenuBar();
 
@@ -37,8 +96,10 @@ $fileMenu->addItem('Beenden', function () use ($app) {
 
 // Settings Menu
 $settingsMenu = new Menu(title: 'Einstellungen');
-$settingsMenu->addItem('Optionen', function () {
-    echo "Optionen clicked\n";
+$settingsMenu->addItem('Optionen', function () use ($menuBar, $modal, $apiKeyInput, &$currentApiKey) {
+    $menuBar->closeAllMenus();
+    $apiKeyInput->setValue($currentApiKey);
+    $modal->setVisible(true);
 });
 $settingsMenu->addItem('Sprache', function () {
     echo "Sprache clicked\n";
@@ -105,20 +166,47 @@ $mainContainer->addComponent($tabContainer);
 // === 3. StatusBar ===
 $statusBar = new StatusBar();
 $statusBar->addSegment($statusLabel);
+$fpsLabel = new Label(
+    text: 'FPS: --',
+    style: 'basis-1/8 text-black border-l',
+);
 $statusBar->addSegment(new Label(
     text: 'Zeilen: 10',
     style: 'basis-2/8 text-black border-l',
 )); // Fixed width
+$statusBar->addSegment($fpsLabel);
 $statusBar->addSegment(new Label(
     text: 'Version 1.0',
     style: 'border-l text-black basis-2/8',
 ));
 $mainContainer->addComponent($statusBar);
+
+$cancelButton->setOnClick(function () use ($menuBar, $modal) {
+    $menuBar->closeAllMenus();
+    $modal->setVisible(false);
+});
+
+$saveButton->setOnClick(function () use (&$currentApiKey, $apiKeyInput, $menuBar, $modal, &$statusLabel) {
+    $currentApiKey = trim($apiKeyInput->getValue());
+    if ($statusLabel !== null) {
+        $masked = strlen($currentApiKey) > 4
+            ? (str_repeat('*', max(0, strlen($currentApiKey) - 4)) . substr($currentApiKey, -4))
+            : $currentApiKey;
+        $statusLabel->setText('API-Key gespeichert: ' . $masked);
+    }
+    $menuBar->closeAllMenus();
+    $modal->setVisible(false);
+});
+
+$mainContainer->addComponent($modal);
 $window->setOnResize(function (Window $window) use (&$statusLabel) {
     $statusLabel->setText(
         'Fenster: ' . $window->getViewport()->windowWidth . 'x' . $window->getViewport()->windowHeight,
     );
 });
+$window->setOnFpsChange(function (float $fps) use ($fpsLabel) {
+    $fpsLabel->setText(sprintf('FPS: %d', max(0, (int) round($fps))));
+});
 // Set root and run
 $window->setRoot($mainContainer);
 $app->addWindow($window);
diff --git a/php-sdl3/.libs/sdl3.o b/php-sdl3/.libs/sdl3.o
index 7e992ee..9144c6d 100644
Binary files a/php-sdl3/.libs/sdl3.o and b/php-sdl3/.libs/sdl3.o differ
diff --git a/php-sdl3/.libs/sdl3.so b/php-sdl3/.libs/sdl3.so
index 83caf72..e6c55b6 100755
Binary files a/php-sdl3/.libs/sdl3.so and b/php-sdl3/.libs/sdl3.so differ
diff --git a/php-sdl3/.libs/sdl3_events.o b/php-sdl3/.libs/sdl3_events.o
index a5aa257..d501645 100644
Binary files a/php-sdl3/.libs/sdl3_events.o and b/php-sdl3/.libs/sdl3_events.o differ
diff --git a/php-sdl3/modules/sdl3.so b/php-sdl3/modules/sdl3.so
index 83caf72..e6c55b6 100755
Binary files a/php-sdl3/modules/sdl3.so and b/php-sdl3/modules/sdl3.so differ
diff --git a/php-sdl3/sdl3.c b/php-sdl3/sdl3.c
index 9ea202c..1f1d8f5 100644
--- a/php-sdl3/sdl3.c
+++ b/php-sdl3/sdl3.c
@@ -909,6 +909,9 @@ const zend_function_entry sdl3_functions[] = {
     PHP_FE(sdl_poll_event, arginfo_sdl_poll_event)
     PHP_FE(sdl_wait_event, arginfo_sdl_wait_event)
     PHP_FE(sdl_wait_event_timeout, arginfo_sdl_wait_event_timeout)
+    PHP_FE(sdl_get_mod_state, arginfo_sdl_get_mod_state)
+    PHP_FE(sdl_get_clipboard_text, arginfo_sdl_get_clipboard_text)
+    PHP_FE(sdl_set_clipboard_text, arginfo_sdl_set_clipboard_text)
 
     PHP_FE_END
 };
diff --git a/php-sdl3/sdl3_events.c b/php-sdl3/sdl3_events.c
index 9f632aa..9b623d4 100644
--- a/php-sdl3/sdl3_events.c
+++ b/php-sdl3/sdl3_events.c
@@ -55,6 +55,29 @@ void sdl3_events_register_constants(int module_number) {
     REGISTER_LONG_CONSTANT("SDLK_RIGHT", SDLK_RIGHT, CONST_CS | CONST_PERSISTENT);
     REGISTER_LONG_CONSTANT("SDLK_UP", SDLK_UP, CONST_CS | CONST_PERSISTENT);
     REGISTER_LONG_CONSTANT("SDLK_DOWN", SDLK_DOWN, CONST_CS | CONST_PERSISTENT);
+    REGISTER_LONG_CONSTANT("SDLK_HOME", SDLK_HOME, CONST_CS | CONST_PERSISTENT);
+    REGISTER_LONG_CONSTANT("SDLK_END", SDLK_END, CONST_CS | CONST_PERSISTENT);
+
+    // Letter keys for shortcuts
+    REGISTER_LONG_CONSTANT("SDLK_A", SDLK_A, CONST_CS | CONST_PERSISTENT);
+    REGISTER_LONG_CONSTANT("SDLK_C", SDLK_C, CONST_CS | CONST_PERSISTENT);
+    REGISTER_LONG_CONSTANT("SDLK_V", SDLK_V, CONST_CS | CONST_PERSISTENT);
+    REGISTER_LONG_CONSTANT("SDLK_X", SDLK_X, CONST_CS | CONST_PERSISTENT);
+
+    // Key modifiers
+    REGISTER_LONG_CONSTANT("KMOD_NONE", SDL_KMOD_NONE, CONST_CS | CONST_PERSISTENT);
+    REGISTER_LONG_CONSTANT("KMOD_LSHIFT", SDL_KMOD_LSHIFT, CONST_CS | CONST_PERSISTENT);
+    REGISTER_LONG_CONSTANT("KMOD_RSHIFT", SDL_KMOD_RSHIFT, CONST_CS | CONST_PERSISTENT);
+    REGISTER_LONG_CONSTANT("KMOD_LCTRL", SDL_KMOD_LCTRL, CONST_CS | CONST_PERSISTENT);
+    REGISTER_LONG_CONSTANT("KMOD_RCTRL", SDL_KMOD_RCTRL, CONST_CS | CONST_PERSISTENT);
+    REGISTER_LONG_CONSTANT("KMOD_LALT", SDL_KMOD_LALT, CONST_CS | CONST_PERSISTENT);
+    REGISTER_LONG_CONSTANT("KMOD_RALT", SDL_KMOD_RALT, CONST_CS | CONST_PERSISTENT);
+    REGISTER_LONG_CONSTANT("KMOD_LGUI", SDL_KMOD_LGUI, CONST_CS | CONST_PERSISTENT);
+    REGISTER_LONG_CONSTANT("KMOD_RGUI", SDL_KMOD_RGUI, CONST_CS | CONST_PERSISTENT);
+    REGISTER_LONG_CONSTANT("KMOD_CTRL", SDL_KMOD_CTRL, CONST_CS | CONST_PERSISTENT);
+    REGISTER_LONG_CONSTANT("KMOD_SHIFT", SDL_KMOD_SHIFT, CONST_CS | CONST_PERSISTENT);
+    REGISTER_LONG_CONSTANT("KMOD_ALT", SDL_KMOD_ALT, CONST_CS | CONST_PERSISTENT);
+    REGISTER_LONG_CONSTANT("KMOD_GUI", SDL_KMOD_GUI, CONST_CS | CONST_PERSISTENT);
 }
 
 PHP_FUNCTION(sdl_poll_event) {
@@ -173,3 +196,35 @@ PHP_FUNCTION(sdl_wait_event_timeout) {
     add_assoc_long(return_value, "type", event.type);
     add_assoc_long(return_value, "timestamp", event.common.timestamp);
 }
+
+PHP_FUNCTION(sdl_get_mod_state) {
+    SDL_Keymod mod = SDL_GetModState();
+    RETURN_LONG((zend_long)mod);
+}
+
+PHP_FUNCTION(sdl_get_clipboard_text) {
+    char *text = SDL_GetClipboardText();
+
+    if (text == NULL) {
+        RETURN_EMPTY_STRING();
+    }
+
+    RETVAL_STRING(text);
+    SDL_free(text);
+}
+
+PHP_FUNCTION(sdl_set_clipboard_text) {
+    char *text;
+    size_t text_len;
+
+    if (zend_parse_parameters(ZEND_NUM_ARGS(), "s", &text, &text_len) == FAILURE) {
+        RETURN_THROWS();
+    }
+
+    if (SDL_SetClipboardText(text) < 0) {
+        php_error_docref(NULL, E_WARNING, "SDL_SetClipboardText failed: %s", SDL_GetError());
+        RETURN_FALSE;
+    }
+
+    RETURN_TRUE;
+}
diff --git a/php-sdl3/sdl3_events.h b/php-sdl3/sdl3_events.h
index 3c94642..0a8a5b5 100644
--- a/php-sdl3/sdl3_events.h
+++ b/php-sdl3/sdl3_events.h
@@ -8,6 +8,9 @@
 PHP_FUNCTION(sdl_poll_event);
 PHP_FUNCTION(sdl_wait_event);
 PHP_FUNCTION(sdl_wait_event_timeout);
+PHP_FUNCTION(sdl_get_mod_state);
+PHP_FUNCTION(sdl_get_clipboard_text);
+PHP_FUNCTION(sdl_set_clipboard_text);
 
 // Argument Info
 ZEND_BEGIN_ARG_INFO_EX(arginfo_sdl_poll_event, 0, 0, 0)
@@ -20,6 +23,16 @@ ZEND_BEGIN_ARG_INFO_EX(arginfo_sdl_wait_event_timeout, 0, 0, 1)
     ZEND_ARG_INFO(0, timeout_ms)
 ZEND_END_ARG_INFO()
 
+ZEND_BEGIN_ARG_INFO_EX(arginfo_sdl_get_mod_state, 0, 0, 0)
+ZEND_END_ARG_INFO()
+
+ZEND_BEGIN_ARG_INFO_EX(arginfo_sdl_get_clipboard_text, 0, 0, 0)
+ZEND_END_ARG_INFO()
+
+ZEND_BEGIN_ARG_INFO_EX(arginfo_sdl_set_clipboard_text, 0, 0, 1)
+    ZEND_ARG_INFO(0, text)
+ZEND_END_ARG_INFO()
+
 // Funktion zum Registrieren von Event-Konstanten
 void sdl3_events_register_constants(int module_number);
 
diff --git a/src/Framework/Application.php b/src/Framework/Application.php
index f8ad824..ea32b08 100644
--- a/src/Framework/Application.php
+++ b/src/Framework/Application.php
@@ -81,7 +81,11 @@ class Application
      */
     public function run(): void
     {
+        $targetFps = 60;
+        $targetFrameDuration = $targetFps > 0 ? (1.0 / $targetFps) : 0.0;
+
         while ($this->running && count($this->windows) > 0) {
+            $frameStart = microtime(true);
             // Layout all windows FIRST (sets window references and calculates positions)
             foreach ($this->windows as $windowId => $window) {
                 $window->layout();
@@ -178,8 +182,13 @@ class Application
                 }
             }
 
-            // Limit frame rate to ~60 FPS
-            usleep(16666);
+            if ($targetFrameDuration > 0) {
+                $elapsed = microtime(true) - $frameStart;
+                $timeToSleep = $targetFrameDuration - $elapsed;
+                if ($timeToSleep > 0) {
+                    usleep((int) ($timeToSleep * 1_000_000));
+                }
+            }
         }
 
         // Cleanup remaining windows
diff --git a/src/Tailwind/Model/Style.php b/src/Tailwind/Model/Style.php
index fa1cdec..23db85d 100644
--- a/src/Tailwind/Model/Style.php
+++ b/src/Tailwind/Model/Style.php
@@ -14,4 +14,11 @@ class Style
         )
     {
     }
-}
\ No newline at end of file
+
+    public function __clone()
+    {
+        if (is_object($this->style)) {
+            $this->style = clone $this->style;
+        }
+    }
+}
diff --git a/src/Tailwind/Model/StyleCollection.php b/src/Tailwind/Model/StyleCollection.php
index 18a3b1e..a0b6db8 100644
--- a/src/Tailwind/Model/StyleCollection.php
+++ b/src/Tailwind/Model/StyleCollection.php
@@ -53,4 +53,14 @@ class StyleCollection extends TypedCollection
 
         return $tmp;
     }
-}
\ No newline at end of file
+
+    public function __clone()
+    {
+        $cloned = [];
+        foreach ($this->items() as $style) {
+            $cloned[] = clone $style;
+        }
+
+        $this->setElements($cloned);
+    }
+}
diff --git a/src/Tailwind/StyleParser.php b/src/Tailwind/StyleParser.php
index 60e5cab..653c389 100644
--- a/src/Tailwind/StyleParser.php
+++ b/src/Tailwind/StyleParser.php
@@ -10,13 +10,24 @@ use PHPNative\Tailwind\Style\Style;
 
 class StyleParser
 {
+    private static array $cache = [];
+
     public static function parse($style): StyleCollection
     {
         $computed = new StyleCollection();
-        if($style === null || strlen(trim($style)) === 0) {
+        if($style === null) {
             return $computed;
         }
-        $styles = explode(" ", $style);
+        $normalized = trim(preg_replace('/\s+/', ' ', $style));
+        if ($normalized === '') {
+            return $computed;
+        }
+
+        if (isset(self::$cache[$normalized])) {
+            return clone self::$cache[$normalized];
+        }
+
+        $styles = explode(" ", $normalized);
 
         foreach($styles as $styleStr) {
             $styleStr = trim($styleStr);
@@ -39,9 +50,17 @@ class StyleParser
             }
             $computed->add($s);
         }
+
+        self::$cache[$normalized] = clone $computed;
+
         return $computed;
     }
 
+    public static function clearCache(): void
+    {
+        self::$cache = [];
+    }
+
     private static function parseSimpleStyle(string $style): ?Style
     {
         if($pd = \PHPNative\Tailwind\Parser\Padding::parse($style)) {
diff --git a/src/Ui/Component.php b/src/Ui/Component.php
index adf734c..35a66f7 100644
--- a/src/Ui/Component.php
+++ b/src/Ui/Component.php
@@ -454,11 +454,11 @@ abstract class Component
      * @param int $keycode SDL keycode
      * @return bool True if event was handled
      */
-    public function handleKeyDown(int $keycode): bool
+    public function handleKeyDown(int $keycode, int $mod = 0): bool
     {
         // Default implementation: propagate to children
         foreach ($this->children as $child) {
-            if ($child->handleKeyDown($keycode)) {
+            if ($child->handleKeyDown($keycode, $mod)) {
                 return true;
             }
         }
diff --git a/src/Ui/Widget/Container.php b/src/Ui/Widget/Container.php
index 952801d..e356139 100644
--- a/src/Ui/Widget/Container.php
+++ b/src/Ui/Widget/Container.php
@@ -130,19 +130,17 @@ class Container extends Component
         // Layout overlays separately (they position themselves)
         foreach ($this->children as $child) {
             if ($child->isOverlay()) {
-                // Give overlay a viewport based on the window size
-                // The overlay can then adjust its position in its own layout() method
-                if (!isset($child->getViewport()->windowWidth)) {
-                    $overlayViewport = new Viewport(
-                        x: 0,
-                        y: 0,
-                        width: $this->contentViewport->windowWidth,
-                        height: $this->contentViewport->windowHeight,
-                        windowWidth: $this->contentViewport->windowWidth,
-                        windowHeight: $this->contentViewport->windowHeight,
-                    );
-                    $child->setViewport($overlayViewport);
-                }
+                // Overlays always get a full-window viewport; they will decide inner layout themselves
+                $overlayViewport = new Viewport(
+                    x: 0,
+                    y: 0,
+                    width: $this->contentViewport->windowWidth,
+                    height: $this->contentViewport->windowHeight,
+                    windowWidth: $this->contentViewport->windowWidth,
+                    windowHeight: $this->contentViewport->windowHeight,
+                );
+                $child->setViewport($overlayViewport);
+                $child->setContentViewport(clone $overlayViewport);
                 $child->layout($textRenderer);
             }
         }
@@ -441,6 +439,17 @@ class Container extends Component
         // at the global level to ensure they appear on top of everything
     }
 
+    /**
+     * Returns the computed content width/height within the container (excludes overlays).
+     */
+    public function getContentSize(): array
+    {
+        return [
+            'width' => $this->contentWidth,
+            'height' => $this->contentHeight,
+        ];
+    }
+
     private function renderScrollbars(&$renderer, array $overflow): void
     {
         $scrollbarColor = [100, 100, 100, 200]; // Gray with some transparency
diff --git a/src/Ui/Widget/Modal.php b/src/Ui/Widget/Modal.php
new file mode 100644
index 0000000..4af2db7
--- /dev/null
+++ b/src/Ui/Widget/Modal.php
@@ -0,0 +1,176 @@
+<?php
+
+namespace PHPNative\Ui\Widget;
+
+use PHPNative\Framework\TextRenderer;
+use PHPNative\Tailwind\Style\Background;
+use PHPNative\Ui\Component;
+use PHPNative\Ui\Viewport;
+
+class Modal extends Container
+{
+    private Container $content;
+    private int $backdropAlpha;
+
+    public function __construct(
+        Container $content,
+        string $style = 'flex items-center justify-center bg-black',
+        int $backdropAlpha = 160,
+    ) {
+        parent::__construct(trim($style));
+
+        $this->content = $content;
+        $this->backdropAlpha = max(0, min(255, $backdropAlpha));
+
+        $this->setOverlay(true);
+        $this->setVisible(false);
+        $this->setZIndex(1000);
+        $this->setUseTextureCache(false);
+
+        $this->addComponent($content);
+    }
+
+    public function layout(null|TextRenderer $textRenderer = null): void
+    {
+        $windowViewport = $this->attachedWindow?->getViewport();
+        if ($windowViewport instanceof Viewport) {
+            $referenceViewport = $windowViewport;
+        } else {
+            $referenceViewport = $this->getParent()?->getViewport() ?? $this->getViewport();
+        }
+        $overlayViewport = new Viewport(
+            x: 0,
+            y: 0,
+            width: $referenceViewport->windowWidth,
+            height: $referenceViewport->windowHeight,
+            windowWidth: $referenceViewport->windowWidth,
+            windowHeight: $referenceViewport->windowHeight,
+        );
+
+        // Set viewport for the modal background (full window)
+        $this->setViewport($overlayViewport);
+        $this->setContentViewport(clone $overlayViewport);
+
+        // Parse styles for the modal background
+        $styleCollection = \PHPNative\Tailwind\StyleParser::parse($this->style);
+        $this->computedStyles = $styleCollection->getValidStyles(
+            \PHPNative\Tailwind\Style\MediaQueryEnum::normal,
+            \PHPNative\Tailwind\Style\StateEnum::normal,
+        );
+
+        if (isset($this->computedStyles[Background::class])) {
+            $this->computedStyles[Background::class]->color->alpha = $this->backdropAlpha;
+        }
+
+        // Calculate max size for content (with padding)
+        $windowWidth = $overlayViewport->width;
+        $windowHeight = $overlayViewport->height;
+        $maxWidth = max(240, $windowWidth - 80);
+        $maxHeight = max(160, $windowHeight - 80);
+
+        // Measure content with max constraints
+        $measurementViewport = new Viewport(
+            x: 0,
+            y: 0,
+            width: $maxWidth,
+            height: $maxHeight,
+            windowWidth: $windowWidth,
+            windowHeight: $windowHeight,
+        );
+
+        $this->content->setViewport($measurementViewport);
+        $this->content->setContentViewport(clone $measurementViewport);
+        $this->content->layout($textRenderer);
+
+        // Get measured size
+        $measuredBounds = $this->content->getViewport();
+        $contentWidth = min($measuredBounds->width, $maxWidth);
+        $contentHeight = min($measuredBounds->height, $maxHeight);
+
+        // Center the content
+        $targetX = (int) max(0, ($windowWidth - $contentWidth) / 2);
+        $targetY = (int) max(0, ($windowHeight - $contentHeight) / 2);
+
+        // Apply final viewport to content
+        $finalViewport = new Viewport(
+            x: $targetX,
+            y: $targetY,
+            width: $contentWidth,
+            height: $contentHeight,
+            windowWidth: $windowWidth,
+            windowHeight: $windowHeight,
+        );
+
+        $this->content->setViewport($finalViewport);
+        $this->content->setContentViewport(clone $finalViewport);
+        $this->content->layout($textRenderer);
+    }
+
+    /**
+     * Allow replacing the content container.
+     */
+    public function setContent(Container $content): void
+    {
+        $this->removeChild($this->content);
+        $this->content = $content;
+        $this->addComponent($content);
+        $this->markDirty(true);
+    }
+
+    /**
+     * Expose the content container for further customization.
+     */
+    public function getContent(): Container
+    {
+        return $this->content;
+    }
+
+    public function setBackdropAlpha(int $alpha): void
+    {
+        $this->backdropAlpha = max(0, min(255, $alpha));
+        $this->markDirty(false);
+    }
+
+    public function handleMouseClick(float $mouseX, float $mouseY, int $button): bool
+    {
+        if (!$this->isVisible()) {
+            return false;
+        }
+
+        parent::handleMouseClick($mouseX, $mouseY, $button);
+        return true;
+    }
+
+    public function handleMouseMove(float $mouseX, float $mouseY): void
+    {
+        if (!$this->isVisible()) {
+            return;
+        }
+
+        parent::handleMouseMove($mouseX, $mouseY);
+    }
+
+    public function handleMouseWheel(float $mouseX, float $mouseY, float $deltaY): bool
+    {
+        if (!$this->isVisible()) {
+            return false;
+        }
+
+        parent::handleMouseWheel($mouseX, $mouseY, $deltaY);
+        return true;
+    }
+
+    private function removeChild(Component $component): void
+    {
+        foreach ($this->children as $index => $child) {
+            if ($child === $component) {
+                if (method_exists($child, 'detachFromWindow')) {
+                    $child->detachFromWindow();
+                }
+                $child->setParent(null);
+                unset($this->children[$index]);
+            }
+        }
+        $this->children = array_values($this->children);
+    }
+}
diff --git a/src/Ui/Widget/TextInput.php b/src/Ui/Widget/TextInput.php
index 9d7a69d..0c6c515 100644
--- a/src/Ui/Widget/TextInput.php
+++ b/src/Ui/Widget/TextInput.php
@@ -13,6 +13,8 @@ class TextInput extends Container
     private int $cursorPosition = 0;
     private float $cursorBlinkTime = 0;
     private bool $cursorVisible = true;
+    private ?int $selectionStart = null;
+    private ?int $selectionEnd = null;
 
     public function __construct(
         string $placeholder = '',
@@ -98,6 +100,11 @@ class TextInput extends Container
             return;
         }
 
+        // Delete selection if any
+        if ($this->hasSelection()) {
+            $this->deleteSelection();
+        }
+
         // Insert text at cursor position
         $before = mb_substr($this->value, 0, $this->cursorPosition);
         $after = mb_substr($this->value, $this->cursorPosition);
@@ -109,15 +116,69 @@ class TextInput extends Container
         }
     }
 
-    public function handleKeyDown(int $keycode): bool
+    public function handleKeyDown(int $keycode, int $mod = 0): bool
     {
         if (!$this->focused) {
             return false;
         }
 
+        // Check for modifier keys
+        $ctrlPressed = ($mod & \KMOD_CTRL) !== 0;
+        $shiftPressed = ($mod & \KMOD_SHIFT) !== 0;
+
+        // Handle Ctrl+A (Select All)
+        if ($ctrlPressed && $keycode === \SDLK_A) {
+            $this->selectionStart = 0;
+            $this->selectionEnd = mb_strlen($this->value);
+            return true;
+        }
+
+        // Handle Ctrl+C (Copy)
+        if ($ctrlPressed && $keycode === \SDLK_C) {
+            if ($this->hasSelection()) {
+                $selectedText = $this->getSelectedText();
+                \sdl_set_clipboard_text($selectedText);
+            }
+            return true;
+        }
+
+        // Handle Ctrl+X (Cut)
+        if ($ctrlPressed && $keycode === \SDLK_X) {
+            if ($this->hasSelection()) {
+                $selectedText = $this->getSelectedText();
+                \sdl_set_clipboard_text($selectedText);
+                $this->deleteSelection();
+            }
+            return true;
+        }
+
+        // Handle Ctrl+V (Paste)
+        if ($ctrlPressed && $keycode === \SDLK_V) {
+            $clipboardText = \sdl_get_clipboard_text();
+            if (!empty($clipboardText)) {
+                // Delete selection if any
+                if ($this->hasSelection()) {
+                    $this->deleteSelection();
+                }
+
+                // Insert clipboard text at cursor
+                $before = mb_substr($this->value, 0, $this->cursorPosition);
+                $after = mb_substr($this->value, $this->cursorPosition);
+                $this->value = $before . $clipboardText . $after;
+                $this->cursorPosition += mb_strlen($clipboardText);
+
+                if ($this->onChange !== null) {
+                    ($this->onChange)($this->value);
+                }
+            }
+            return true;
+        }
+
         switch ($keycode) {
-            case SDLK_BACKSPACE:
-                if ($this->cursorPosition > 0) {
+            case \SDLK_BACKSPACE:
+                if ($this->hasSelection()) {
+                    $this->deleteSelection();
+                } elseif ($this->cursorPosition > 0) {
                     $before = mb_substr($this->value, 0, $this->cursorPosition - 1);
                     $after = mb_substr($this->value, $this->cursorPosition);
                     $this->value = $before . $after;
@@ -129,8 +190,10 @@ class TextInput extends Container
                 }
                 return true;
 
-            case SDLK_DELETE:
-                if ($this->cursorPosition < mb_strlen($this->value)) {
+            case \SDLK_DELETE:
+                if ($this->hasSelection()) {
+                    $this->deleteSelection();
+                } elseif ($this->cursorPosition < mb_strlen($this->value)) {
                     $before = mb_substr($this->value, 0, $this->cursorPosition);
                     $after = mb_substr($this->value, $this->cursorPosition + 1);
                     $this->value = $before . $after;
@@ -141,19 +204,79 @@ class TextInput extends Container
                 }
                 return true;
 
-            case SDLK_LEFT:
+            case \SDLK_LEFT:
                 if ($this->cursorPosition > 0) {
-                    $this->cursorPosition--;
+                    if ($shiftPressed) {
+                        // Start or extend selection
+                        if (!$this->hasSelection()) {
+                            $this->selectionStart = $this->cursorPosition;
+                        }
+                        $this->cursorPosition--;
+                        $this->selectionEnd = $this->cursorPosition;
+                    } else {
+                        // Clear selection and move cursor
+                        if ($this->hasSelection()) {
+                            // Move cursor to start of selection
+                            $this->cursorPosition = min($this->selectionStart, $this->selectionEnd);
+                            $this->clearSelection();
+                        } else {
+                            $this->cursorPosition--;
+                        }
+                    }
                 }
                 return true;
 
-            case SDLK_RIGHT:
+            case \SDLK_RIGHT:
                 if ($this->cursorPosition < mb_strlen($this->value)) {
-                    $this->cursorPosition++;
+                    if ($shiftPressed) {
+                        // Start or extend selection
+                        if (!$this->hasSelection()) {
+                            $this->selectionStart = $this->cursorPosition;
+                        }
+                        $this->cursorPosition++;
+                        $this->selectionEnd = $this->cursorPosition;
+                    } else {
+                        // Clear selection and move cursor
+                        if ($this->hasSelection()) {
+                            // Move cursor to end of selection
+                            $this->cursorPosition = max($this->selectionStart, $this->selectionEnd);
+                            $this->clearSelection();
+                        } else {
+                            $this->cursorPosition++;
+                        }
+                    }
                 }
                 return true;
 
-            case SDLK_RETURN:
+            case \SDLK_HOME:
+                if ($shiftPressed) {
+                    // Extend selection to start
+                    if (!$this->hasSelection()) {
+                        $this->selectionStart = $this->cursorPosition;
+                    }
+                    $this->cursorPosition = 0;
+                    $this->selectionEnd = $this->cursorPosition;
+                } else {
+                    $this->cursorPosition = 0;
+                    $this->clearSelection();
+                }
+                return true;
+
+            case \SDLK_END:
+                if ($shiftPressed) {
+                    // Extend selection to end
+                    if (!$this->hasSelection()) {
+                        $this->selectionStart = $this->cursorPosition;
+                    }
+                    $this->cursorPosition = mb_strlen($this->value);
+                    $this->selectionEnd = $this->cursorPosition;
+                } else {
+                    $this->cursorPosition = mb_strlen($this->value);
+                    $this->clearSelection();
+                }
+                return true;
+
+            case \SDLK_RETURN:
                 // Enter key - can be handled by parent
                 return false;
         }
@@ -174,6 +297,53 @@ class TextInput extends Container
     public function blur(): void
     {
         $this->focused = false;
+        $this->clearSelection();
+    }
+
+    private function hasSelection(): bool
+    {
+        return $this->selectionStart !== null &&
+               $this->selectionEnd !== null &&
+               $this->selectionStart !== $this->selectionEnd;
+    }
+
+    private function getSelectedText(): string
+    {
+        if (!$this->hasSelection()) {
+            return '';
+        }
+
+        $start = min($this->selectionStart, $this->selectionEnd);
+        $end = max($this->selectionStart, $this->selectionEnd);
+
+        return mb_substr($this->value, $start, $end - $start);
+    }
+
+    private function deleteSelection(): void
+    {
+        if (!$this->hasSelection()) {
+            return;
+        }
+
+        $start = min($this->selectionStart, $this->selectionEnd);
+        $end = max($this->selectionStart, $this->selectionEnd);
+
+        $before = mb_substr($this->value, 0, $start);
+        $after = mb_substr($this->value, $end);
+        $this->value = $before . $after;
+        $this->cursorPosition = $start;
+
+        $this->clearSelection();
+
+        if ($this->onChange !== null) {
+            ($this->onChange)($this->value);
+        }
+    }
+
+    private function clearSelection(): void
+    {
+        $this->selectionStart = null;
+        $this->selectionEnd = null;
     }
 
     public function render(&$renderer, null|TextRenderer $textRenderer = null): void
@@ -204,6 +374,36 @@ class TextInput extends Container
             'h' => $this->viewport->height - 4,
         ]);
 
+        // Render selection highlight
+        if ($this->hasSelection() && $textRenderer !== null && $textRenderer->isInitialized()) {
+            $start = min($this->selectionStart, $this->selectionEnd);
+            $end = max($this->selectionStart, $this->selectionEnd);
+
+            $textBeforeSelection = mb_substr($this->value, 0, $start);
+            $selectedText = mb_substr($this->value, $start, $end - $start);
+
+            $selectionX = $this->viewport->x + 6;
+            if (!empty($textBeforeSelection)) {
+                $size = $textRenderer->measureText($textBeforeSelection);
+                $selectionX += $size[0];
+            }
+
+            $selectionWidth = 0;
+            if (!empty($selectedText)) {
+                $size = $textRenderer->measureText($selectedText);
+                $selectionWidth = $size[0];
+            }
+
+            // Draw selection background (blue)
+            sdl_set_render_draw_color($renderer, 59, 130, 246, 100); // Blue with transparency
+            sdl_render_fill_rect($renderer, [
+                'x' => $selectionX,
+                'y' => $this->viewport->y + 4,
+                'w' => $selectionWidth,
+                'h' => $this->viewport->height - 8,
+            ]);
+        }
+
         // Render text or placeholder
         if ($textRenderer !== null && $textRenderer->isInitialized()) {
             $displayText = empty($this->value) ? $this->placeholder : $this->value;
diff --git a/src/Ui/Window.php b/src/Ui/Window.php
index 75d706d..0b4d827 100644
--- a/src/Ui/Window.php
+++ b/src/Ui/Window.php
@@ -18,6 +18,10 @@ class Window
     private float $pixelRatio = 2;
     private bool $shouldClose = false;
     private $onResize = null;
+    private $onFpsChange = null;
+    private float $lastFpsUpdate = 0.0;
+    private int $frameCounter = 0;
+    private float $currentFps = 0.0;
     public function __construct(
         private string $title,
         private int $width = 800,
@@ -78,6 +82,8 @@ class Window
             height: $this->height,
         );
 
+        $this->lastFpsUpdate = microtime(true);
+
     }
 
     public function setRoot(Component $component): self
@@ -171,10 +177,11 @@ class Window
 
             case SDL_EVENT_KEY_DOWN:
                 $keycode = $event['keycode'] ?? 0;
+                $mod = $event['mod'] ?? 0;
 
                 // Propagate key event to root component
                 if ($this->rootComponent) {
-                    $this->rootComponent->handleKeyDown($keycode);
+                    $this->rootComponent->handleKeyDown($keycode, $mod);
                 }
                 break;
 
@@ -362,6 +369,8 @@ class Window
 
         $this->rootComponent->markClean();
 
+        $this->updateFps();
+
         sdl_render_present($this->renderer);
     }
 
@@ -411,4 +420,31 @@ class Window
     {
         $this->onResize = $callback;
     }
+
+    public function setOnFpsChange(?callable $callback): void
+    {
+        $this->onFpsChange = $callback;
+    }
+
+    public function getCurrentFps(): float
+    {
+        return $this->currentFps;
+    }
+
+    private function updateFps(): void
+    {
+        $this->frameCounter++;
+        $now = microtime(true);
+        $elapsed = $now - $this->lastFpsUpdate;
+
+        if ($elapsed >= 1.0) {
+            $this->currentFps = $this->frameCounter / $elapsed;
+            $this->frameCounter = 0;
+            $this->lastFpsUpdate = $now;
+
+            if ($this->onFpsChange !== null) {
+                ($this->onFpsChange)($this->currentFps);
+            }
+        }
+    }
 }