diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
new file mode 100644
index 0000000..a9211ea
--- /dev/null
+++ b/.github/workflows/ci.yml
@@ -0,0 +1,65 @@
+name: CI
+on: [push]
+
+jobs:
+  phpstan:
+    runs-on: ubuntu-latest
+    steps:
+      - name: Setup PHP
+        uses: shivammathur/setup-php@v2
+        with:
+          php-version: 8.2
+
+      - name: Checkout
+        uses: actions/checkout@v6
+
+      - name: Install the dependencies
+        uses: ramsey/composer-install@v3
+        with:
+          composer-options: "--no-plugins"
+
+      - name: PHPStan
+        run: vendor/bin/phpstan analyse -c phpstan.neon
+
+  rector:
+    runs-on: ubuntu-latest
+    steps:
+      - name: Setup PHP
+        uses: shivammathur/setup-php@v2
+        with:
+          php-version: 8.2
+
+      - name: Checkout
+        uses: actions/checkout@v6
+
+      - name: Install the dependencies
+        uses: ramsey/composer-install@v3
+        with:
+          composer-options: "--no-plugins"
+
+      - name: Rector
+        run: vendor/bin/rector --dry-run --no-progress-bar
+
+  ecs:
+    name: ECS
+    runs-on: ubuntu-latest
+    steps:
+      - name: Setup PHP
+        uses: shivammathur/setup-php@v2
+        with:
+          php-version: 8.2
+          extensions: dom, fileinfo, filter, gd, hash, intl, json, mbstring, mysqli, pcre, pdo_mysql, zlib
+          coverage: none
+
+      - name: Checkout
+        uses: actions/checkout@v6
+        with:
+          show-progress: false
+
+      - name: Install the dependencies
+        uses: ramsey/composer-install@v3
+        with:
+          composer-options: "--no-plugins"
+
+      - name: Run ECS
+        run: vendor/bin/ecs check --no-progress-bar
diff --git a/composer.json b/composer.json
index 0d15999..d2545b4 100644
--- a/composer.json
+++ b/composer.json
@@ -24,6 +24,16 @@
         "contao/core-bundle": "^5.3",
         "symfony/http-kernel": "^6.4 || ^7.0"
     },
+    "require-dev": {
+        "contao/core-bundle": "5.3.*",
+        "rector/rector": "^2.5",
+        "contao/contao-rector": "dev-main",
+        "symplify/easy-coding-standard": "^13.2",
+        "phpstan/phpstan": "^2.2",
+        "phpstan/phpstan-symfony": "^2.0",
+        "contao/manager-plugin": "^2.13",
+        "terminal42/contao-leads": "^3.2"
+    },
     "autoload": {
         "psr-4": {
             "HeimrichHannot\\FormFieldsCollectionBundle\\": "src/"
diff --git a/contao/dca/tl_form_field.php b/contao/dca/tl_form_field.php
index 35b0b79..9c76bd8 100644
--- a/contao/dca/tl_form_field.php
+++ b/contao/dca/tl_form_field.php
@@ -5,14 +5,20 @@
 
 $dca = &$GLOBALS['TL_DCA']['tl_form_field'];
 
-$dca['palettes'][DateTimeWidget::TYPE] = '{type_legend},type,name,label;{fconfig_legend},mandatory,dateTimeType,defaultDateTimeValue;{expert_legend:hide},class,minval,maxval,accesskey,tabindex;{template_legend:hide},customTpl;{invisible_legend:hide},invisible';
+$dca['palettes'][DateTimeWidget::TYPE] = <<<PALETTE
+    {type_legend},type,name,label;
+    {fconfig_legend},mandatory,dateTimeType,defaultDateTimeValue;
+    {expert_legend:collapsed},class,minval,maxval,accesskey,tabindex;
+    {template_legend:collapsed},customTpl;
+    {invisible_legend:collapsed},invisible
+    PALETTE;
 $dca['palettes'][SingleCheckboxWidget::TYPE] = <<< PALETTE
     {type_legend},type,name,label;
     {fconfig_legend},mandatory,help;
     {options_legend},value,text;
-    {expert_legend:hide},class;
-    {template_legend:hide},customTpl;
-    {invisible_legend:hide},invisible
+    {expert_legend:collapsed},class;
+    {template_legend:collapsed},customTpl;
+    {invisible_legend:collapsed},invisible
     PALETTE;
 
 $dca['subpalettes']['defaultDateTimeValue_custom'] = 'value';
@@ -27,7 +33,9 @@
     ],
     'reference' => &$GLOBALS['TL_LANG']['tl_form_field'],
     'default' => 'date',
-    'eval' => ['tl_class' => 'w50'],
+    'eval' => [
+        'tl_class' => 'w50',
+    ],
     'sql' => "varchar(4) NOT NULL default ''",
 ];
 
@@ -45,4 +53,3 @@
     ],
     'sql' => "varchar(8) NOT NULL default ''",
 ];
-
diff --git a/contao/languages/de/default.php b/contao/languages/de/default.php
index 990adfb..a9d0286 100644
--- a/contao/languages/de/default.php
+++ b/contao/languages/de/default.php
@@ -3,11 +3,11 @@
 use HeimrichHannot\FormFieldsCollectionBundle\FrontendWidget\DateTimeWidget;
 use HeimrichHannot\FormFieldsCollectionBundle\FrontendWidget\SingleCheckboxWidget;
 
-$GLOBALS['TL_LANG']['FFL'][DateTimeWidget::TYPE]       = [
+$GLOBALS['TL_LANG']['FFL'][DateTimeWidget::TYPE] = [
     'Datum-/ Zeitfeld (Form Fields Collection)',
-    'Ermöglicht die Eingabe von Datum und/ oder Zeit.'
+    'Ermöglicht die Eingabe von Datum und/ oder Zeit.',
 ];
-$GLOBALS['TL_LANG']['FFL'][SingleCheckboxWidget::TYPE]       = [
+$GLOBALS['TL_LANG']['FFL'][SingleCheckboxWidget::TYPE] = [
     'Checkbox Einzeln (Form Fields Collection)',
-    'Eine einzelne Checkbox, die entweder aktiviert oder deaktiviert sein kann.'
-];
\ No newline at end of file
+    'Eine einzelne Checkbox, die entweder aktiviert oder deaktiviert sein kann.',
+];
diff --git a/contao/languages/de/tl_form_field.php b/contao/languages/de/tl_form_field.php
index 46290e0..34caa66 100644
--- a/contao/languages/de/tl_form_field.php
+++ b/contao/languages/de/tl_form_field.php
@@ -11,4 +11,4 @@
 $lang['defaultDateTimeCustomValue'][0] = 'Benutzerdefinierte Zeit';
 $lang['defaultDateTimeCustomValue'][1] = 'Bitte geben Sie die benutzerdefinierte Zeit ein.';
 $lang['singleCheckboxValue'][0] = 'Checkbox Wert';
-$lang['singleCheckboxValue'][1] = 'Legen Sie den Checkbox-Wert fest. Wenn leer, wird der Wert 1 sein.';
\ No newline at end of file
+$lang['singleCheckboxValue'][1] = 'Legen Sie den Checkbox-Wert fest. Wenn leer, wird der Wert 1 sein.';
diff --git a/contao/languages/en/default.php b/contao/languages/en/default.php
index 3803533..94e79ca 100644
--- a/contao/languages/en/default.php
+++ b/contao/languages/en/default.php
@@ -3,11 +3,11 @@
 use HeimrichHannot\FormFieldsCollectionBundle\FrontendWidget\DateTimeWidget;
 use HeimrichHannot\FormFieldsCollectionBundle\FrontendWidget\SingleCheckboxWidget;
 
-$GLOBALS['TL_LANG']['FFL'][DateTimeWidget::TYPE]       = [
+$GLOBALS['TL_LANG']['FFL'][DateTimeWidget::TYPE] = [
     'Date/ time (Form Fields Collection)',
-    'A date or time field.'
+    'A date or time field.',
 ];
-$GLOBALS['TL_LANG']['FFL'][SingleCheckboxWidget::TYPE]       = [
+$GLOBALS['TL_LANG']['FFL'][SingleCheckboxWidget::TYPE] = [
     'Checkbox Single (Form Fields Collection)',
-    'A single checkbox that can be either checked or unchecked.'
-];
\ No newline at end of file
+    'A single checkbox that can be either checked or unchecked.',
+];
diff --git a/contao/languages/en/tl_form_field.php b/contao/languages/en/tl_form_field.php
index 6569a24..194bed3 100644
--- a/contao/languages/en/tl_form_field.php
+++ b/contao/languages/en/tl_form_field.php
@@ -11,4 +11,4 @@
 $lang['defaultDateTimeCustomValue'][0] = 'Custom date/ time';
 $lang['defaultDateTimeCustomValue'][1] = 'Please enter a custom date/ time.';
 $lang['singleCheckboxValue'][0] = 'Checkbox Value';
-$lang['singleCheckboxValue'][1] = 'Set the checkbox value. If empty, the value will be 1.';
\ No newline at end of file
+$lang['singleCheckboxValue'][1] = 'Set the checkbox value. If empty, the value will be 1.';
diff --git a/ecs.php b/ecs.php
new file mode 100644
index 0000000..4745de0
--- /dev/null
+++ b/ecs.php
@@ -0,0 +1,39 @@
+<?php
+
+declare(strict_types=1);
+
+use PhpCsFixer\Fixer\Basic\BracesPositionFixer;
+use PhpCsFixer\Fixer\Import\NoUnusedImportsFixer;
+use PhpCsFixer\Fixer\Operator\NotOperatorWithSuccessorSpaceFixer;
+use PhpCsFixer\Fixer\Whitespace\MethodChainingIndentationFixer;
+use Symplify\EasyCodingStandard\Config\ECSConfig;
+
+return ECSConfig::configure()
+    ->withPaths([
+        __DIR__ . '/src',
+        __DIR__ . '/contao',
+
+    ])
+
+    // add a single rule
+    ->withRules([
+        NoUnusedImportsFixer::class,
+        BracesPositionFixer::class,
+    ])
+
+    // add sets - group of rules
+    ->withPreparedSets(
+        arrays: true,
+        comments: true,
+        docblocks: true,
+        spaces: true,
+        namespaces: true,
+    )
+    ->withPhpCsFixerSets(symfony: true)
+    ->withSkip([
+        NotOperatorWithSuccessorSpaceFixer::class,
+        MethodChainingIndentationFixer::class => [
+            '*/DependencyInjection/Configuration.php',
+            'src/*Bundle.php'
+        ],
+    ]);
\ No newline at end of file
diff --git a/phpstan.neon b/phpstan.neon
new file mode 100644
index 0000000..182927a
--- /dev/null
+++ b/phpstan.neon
@@ -0,0 +1,11 @@
+parameters:
+  level: 4
+  paths:
+    - src
+    - contao
+#  universalObjectCratesClasses:
+#    - Contao\Database\Result
+#    - Contao\Model
+#    - Contao\Template
+includes:
+  - vendor/phpstan/phpstan-symfony/extension.neon
\ No newline at end of file
diff --git a/rector.php b/rector.php
new file mode 100644
index 0000000..d7561e4
--- /dev/null
+++ b/rector.php
@@ -0,0 +1,46 @@
+<?php
+
+declare(strict_types=1);
+
+use Contao\Rector\Set\ContaoLevelSetList;
+use Contao\Rector\Set\ContaoSetList;
+use Rector\Config\RectorConfig;
+use Rector\Php81\Rector\Array_\ArrayToFirstClassCallableRector;
+use Rector\Php84\Rector\Param\ExplicitNullableParamTypeRector;
+use Rector\Set\ValueObject\LevelSetList;
+use Rector\TypeDeclaration\Rector\ClassMethod\AddVoidReturnTypeWhereNoReturnRector;
+use Rector\ValueObject\PhpVersion;
+
+return RectorConfig::configure()
+    ->withPaths([
+        __DIR__ . '/src',
+        __DIR__ . '/contao',
+
+    ])
+    ->withPhpVersion(PhpVersion::PHP_84)
+    ->withRules([
+        AddVoidReturnTypeWhereNoReturnRector::class,
+        # In Vorbereitung für PHP 8.4:
+        ExplicitNullableParamTypeRector::class,
+    ])
+
+    ->withImportNames(
+        importShortClasses: false,
+        removeUnusedImports: true
+    )
+    ->withComposerBased(
+        twig: true,
+        doctrine: true,
+        phpunit: true,
+        symfony: true,
+    )
+    ->withSets([
+        LevelSetList::UP_TO_PHP_82,
+        ContaoLevelSetList::UP_TO_CONTAO_53,
+        ContaoSetList::FQCN,
+        ContaoSetList::ANNOTATIONS_TO_ATTRIBUTES,
+    ])
+    ->withSkip([
+        ArrayToFirstClassCallableRector::class,
+    ])
+    ;
\ No newline at end of file
diff --git a/src/ContaoManager/Plugin.php b/src/ContaoManager/Plugin.php
index 77e800d..c0a31c8 100644
--- a/src/ContaoManager/Plugin.php
+++ b/src/ContaoManager/Plugin.php
@@ -24,4 +24,4 @@ public function registerContainerConfiguration(LoaderInterface $loader, array $m
     {
         $loader->load('@HeimrichHannotFormFieldsCollectionBundle/config/services.yaml');
     }
-}
\ No newline at end of file
+}
diff --git a/src/EventListener/DateTimeListener.php b/src/EventListener/DateTimeListener.php
index 18f2dca..edb99dc 100644
--- a/src/EventListener/DateTimeListener.php
+++ b/src/EventListener/DateTimeListener.php
@@ -12,12 +12,13 @@ class DateTimeListener
     #[AsCallback(table: 'tl_form_field', target: 'config.onload')]
     public function onLoadCallback(DataContainer $dc): void
     {
-        if (!$dc || !$dc->id) {
+        if (!$dc->id) {
             return;
         }
 
+        /** @var \HeimrichHannot\FormFieldsCollectionBundle\Model\FormFieldModel|null $widget */
         $widget = FormFieldModel::findByPk($dc->id);
-        if (!$widget || (DateTimeWidget::TYPE !== $widget->type)) {
+        if (DateTimeWidget::TYPE !== $widget?->type) {
             return;
         }
 
@@ -34,6 +35,6 @@ public function onLoadCallback(DataContainer $dc): void
                 $GLOBALS['TL_DCA']['tl_form_field']['fields']['maxval']['eval']['rgxp'] = 'time';
                 $GLOBALS['TL_DCA']['tl_form_field']['fields']['value']['label'] = &$GLOBALS['TL_LANG']['tl_form_field']['defaultDateTimeCustomValue'];
                 break;
-        };
+        }
     }
-}
\ No newline at end of file
+}
diff --git a/src/EventListener/Integrations/LeadsListener.php b/src/EventListener/Integrations/LeadsListener.php
index 6823af1..d88a6d9 100644
--- a/src/EventListener/Integrations/LeadsListener.php
+++ b/src/EventListener/Integrations/LeadsListener.php
@@ -20,17 +20,19 @@ public function onFormDataValueEvent(FormDataValueEvent $event): void
         $format = match ($event->getField()['dateTimeType']) {
             'date' => Date::getNumericDateFormat(),
             'time' => Date::getNumericTimeFormat(),
-            'default' => null,
+            default => null,
         };
 
         if (null === $format) {
             $event->stopPropagation();
+
             return;
         }
 
         try {
             $event->setValue((new Date($event->getValue(), $format))->tstamp);
-        } catch (\Exception) {}
+        } catch (\Exception) {
+        }
 
         $event->stopPropagation();
     }
@@ -45,18 +47,20 @@ public function onFormDataLabelEvent(FormDataLabelEvent $event): void
         $format = match ($event->getField()['dateTimeType']) {
             'date' => Date::getNumericDateFormat(),
             'time' => Date::getNumericTimeFormat(),
-            'default' => null,
+            default => null,
         };
 
         if (null === $format) {
             $event->stopPropagation();
+
             return;
         }
 
         try {
             $event->setLabel(Date::parse($format, $event->getValue()));
-        } catch (\Exception) {}
+        } catch (\Exception) {
+        }
 
         $event->stopPropagation();
     }
-}
\ No newline at end of file
+}
diff --git a/src/EventListener/SingleCheckboxListener.php b/src/EventListener/SingleCheckboxListener.php
index ec2eb88..82776b5 100644
--- a/src/EventListener/SingleCheckboxListener.php
+++ b/src/EventListener/SingleCheckboxListener.php
@@ -12,7 +12,7 @@ class SingleCheckboxListener
     #[AsCallback(table: 'tl_form_field', target: 'config.onload')]
     public function onLoadCallback(DataContainer $dc): void
     {
-        if (!$dc || !$dc->id) {
+        if (!$dc->id) {
             return;
         }
 
@@ -26,4 +26,4 @@ public function onLoadCallback(DataContainer $dc): void
         $GLOBALS['TL_DCA']['tl_form_field']['fields']['text']['eval']['mandatory'] = true;
         $GLOBALS['TL_DCA']['tl_form_field']['fields']['value']['label'] = &$GLOBALS['TL_LANG']['tl_form_field']['singleCheckboxValue'];
     }
-}
\ No newline at end of file
+}
diff --git a/src/FormFieldModel.php b/src/FormFieldModel.php
new file mode 100644
index 0000000..8856dd1
--- /dev/null
+++ b/src/FormFieldModel.php
@@ -0,0 +1,10 @@
+<?php
+
+namespace HeimrichHannot\FormFieldsCollectionBundle\Model;
+
+/**
+ * @property string $dateTimeType
+ */
+class FormFieldModel extends \Contao\FormFieldModel
+{
+}
diff --git a/src/FrontendWidget/DateTimeWidget.php b/src/FrontendWidget/DateTimeWidget.php
index c1d311c..53319c2 100644
--- a/src/FrontendWidget/DateTimeWidget.php
+++ b/src/FrontendWidget/DateTimeWidget.php
@@ -6,6 +6,11 @@
 use Contao\FormFieldModel;
 use Contao\FormText;
 
+/**
+ * @property string $defaultDateTimeValue
+ * @property string $dateTimeType
+ * @property string $parentTemplate
+ */
 #[\AllowDynamicProperties]
 class DateTimeWidget extends FormText
 {
@@ -22,13 +27,15 @@ public function __construct($arrAttributes = null)
             if ($fieldModel) {
                 $this->value = match ($this->dateTimeType) {
                     'date' => Date::parse('Y-m-d', $fieldModel->value),
-                    'time' => Date::parse("H:i", $fieldModel->value),
+                    'time' => Date::parse('H:i', $fieldModel->value),
+                    default => '',
                 };
             }
         } elseif ('current' === $this->defaultDateTimeValue) {
             $this->value = match ($this->dateTimeType) {
-                "", 'date' => date('Y-m-d'),
+                '', 'date' => date('Y-m-d'),
                 'time' => date('H:i'),
+                default => '',
             };
         }
 
@@ -61,24 +68,28 @@ protected function validator($varInput)
         return parent::validator(match ($this->dateTimeType) {
             'date' => \DateTime::createFromFormat('Y-m-d', $varInput)->format(Date::getNumericDateFormat()),
             'time' => \DateTime::createFromFormat('H:i', $varInput)->format(Date::getNumericTimeFormat()),
+            default => $varInput,
         });
     }
 
-    public function parse($arrAttributes=null)
+    public function parse($arrAttributes = null)
     {
         // restore field value on errors
         if ($this->hasErrors()) {
             $dateTime = match ($this->dateTimeType) {
                 'date' => \DateTime::createFromFormat(Date::getNumericDateFormat(), $this->value),
                 'time' => \DateTime::createFromFormat(Date::getNumericTimeFormat(), $this->value),
+                default => $this->value,
             };
             if (false !== $dateTime) {
                 $this->value = match ($this->dateTimeType) {
                     'date' => $dateTime->format('Y-m-d'),
                     'time' => $dateTime->format('H:i'),
+                    default => $this->value,
                 };
             }
         }
+
         return parent::parse($arrAttributes);
     }
-}
\ No newline at end of file
+}
diff --git a/src/FrontendWidget/SingleCheckboxWidget.php b/src/FrontendWidget/SingleCheckboxWidget.php
index c9eec1e..ba0740e 100644
--- a/src/FrontendWidget/SingleCheckboxWidget.php
+++ b/src/FrontendWidget/SingleCheckboxWidget.php
@@ -6,6 +6,9 @@
 use Contao\Input;
 use Contao\System;
 
+/**
+ * @property string $text
+ */
 class SingleCheckboxWidget extends FormCheckbox
 {
     public const TYPE = 'huh_single_checkbox';
@@ -14,10 +17,10 @@ class SingleCheckboxWidget extends FormCheckbox
 
     protected function getOption(): array
     {
-        $text = System::getContainer()->get('contao.insert_tag.parser')->replaceInline((string)$this->text);
+        $text = System::getContainer()->get('contao.insert_tag.parser')->replaceInline((string) $this->text);
         if (
-            preg_match('/^\s*<p\b[^>]*>(.*)<\/p>\s*$/is', $text, $matches) === 1
-            && preg_match('/<\/?p\b/i', $matches[1]) !== 1
+            1 === preg_match('/^\s*<p\b[^>]*>(.*)<\/p>\s*$/is', (string) $text, $matches)
+            && 1 !== preg_match('/<\/?p\b/i', $matches[1])
         ) {
             $text = trim($matches[1]);
         }
@@ -29,7 +32,7 @@ protected function getOption(): array
             'id' => $this->strId,
             'value' => $value,
             'attributes' => $this->getAttributes(),
-            'label' => $text
+            'label' => $text,
         ];
         if ($this->mandatory) {
             $option['mandatory'] = true;
@@ -38,25 +41,26 @@ protected function getOption(): array
         if (!Input::isPost()) {
             $option['checked'] = false;
         } else {
-            $option['checked'] = (string)$this->varValue === (string)$value;
+            $option['checked'] = (string) $this->varValue === (string) $value;
         }
 
         return $option;
     }
 
-    public function getAttributes($arrStrip = array())
+    public function getAttributes($arrStrip = [])
     {
         if ($this->mandatory) {
             $this->arrAttributes['required'] = 'required';
         }
+
         return parent::getAttributes($arrStrip);
     }
 
-
     protected function isValidOption($varInput): bool
     {
         // set arrOptions to make parent validation work
         $this->arrOptions = [$this->getOption()];
+
         return parent::isValidOption($varInput);
     }
-}
\ No newline at end of file
+}
diff --git a/src/HeimrichHannotFormFieldsCollectionBundle.php b/src/HeimrichHannotFormFieldsCollectionBundle.php
index f86f57a..9b00af8 100644
--- a/src/HeimrichHannotFormFieldsCollectionBundle.php
+++ b/src/HeimrichHannotFormFieldsCollectionBundle.php
@@ -10,5 +10,4 @@ public function getPath(): string
     {
         return \dirname(__DIR__);
     }
-
-}
\ No newline at end of file
+}