- The three market Content Blocks preview as compact collapsible rows:

thumbnail of the actual image (hero background, intro image, insights
  cover), key copy in the summary line, full details expanded; card and
  intro-paragraph previews are wrapped in the same mechanism
- New SubmarketPluginPreview for vitec_usecaselist / vitec_productfeature /
  vitec_productlist: instead of bare standard boxes they now list the
  selected story titles (flagging stories that still lack a quote), the
  featured product and the hand-picked products in order
- Container-style collapse for whole page-module COLUMNS: a chevron at the
  right of every column header folds a section down to its title row,
  state kept per page and colPos in localStorage - the slot view of a
  sub-market page folds to six slim bands
- Previews sit under the page module's pointer-events lock and its
  click-to-edit layer: pointer events are re-enabled inside the collapse
  markup and the toggle runs on pointerdown in the capture phase
- Two more v14 removals fixed on the way, both latent in the OLDER preview
  classes too (Usecaseshow, Modelcard would have crashed the page module):
  GridColumnItem::getRecord() now returns a Domain\Record object, and
  StandaloneView is gone - previews normalize the record via a shared
  helper and render through the ViewFactory

packages/vitec/Classes/Preview/ModelcardPreviewRenderer.php

@@ -11,7 +11,6 @@ use TYPO3\CMS\Core\Database\ConnectionPool;
 use TYPO3\CMS\Core\Resource\ResourceFactory;
 use TYPO3\CMS\Core\Service\FlexFormService;
 use TYPO3\CMS\Core\Utility\GeneralUtility;
-use TYPO3\CMS\Fluid\View\StandaloneView;
 
 /**
  * Page-module preview for the VITEC Card plugin (vitec_modelcard):
@@ -45,7 +44,7 @@ class ModelcardPreviewRenderer extends StandardContentPreviewRenderer
     public function renderPageModulePreviewContent(GridColumnItem $item): string
     {
         try {
-            $record = $item->getRecord();
+            $record = $this->recordArray($item);
 
             $flexFormService = GeneralUtility::makeInstance(FlexFormService::class);
             $flexFormData = $flexFormService->convertFlexFormContentToArray($record['pi_flexform'] ?? '');
@@ -77,8 +76,12 @@ class ModelcardPreviewRenderer extends StandardContentPreviewRenderer
                 }
             }
 
-            $view = GeneralUtility::makeInstance(StandaloneView::class);
-            $view->setTemplatePathAndFilename('EXT:vitec/Resources/Private/Templates/Preview/Modelcard.html');
+            // v14: StandaloneView was removed - views come from the ViewFactory.
+            $view = GeneralUtility::makeInstance(\TYPO3\CMS\Core\View\ViewFactoryInterface::class)
+                ->create(new \TYPO3\CMS\Core\View\ViewFactoryData(
+                    templatePathAndFilename: 'EXT:vitec/Resources/Private/Templates/Preview/Modelcard.html',
+                    request: $GLOBALS['TYPO3_REQUEST'] ?? null,
+                ));
             $view->assignMultiple([
                 'typeLabel' => self::TYPE_LABELS[$modelType] ?? $modelType,
                 'layout' => $layout,
@@ -124,4 +127,21 @@ class ModelcardPreviewRenderer extends StandardContentPreviewRenderer
         }
         return '';
     }
+
+    /**
+     * v14: GridColumnItem::getRecord() returns a Domain\Record object, no
+     * longer an array (found 2026-10-02 - crashed the page module preview).
+     * Normalizes both shapes to the raw database array.
+     *
+     * @return array<string,mixed>
+     */
+    private function recordArray(GridColumnItem $item): array
+    {
+        $record = $item->getRecord();
+        if ($record instanceof \TYPO3\CMS\Core\Domain\Record) {
+            $raw = $record->getRawRecord();
+            return $raw !== null ? $raw->toArray() : [];
+        }
+        return (array)$record;
+    }
 }

packages/vitec/Classes/Preview/SubmarketPluginPreview.php

@@ -0,0 +1,129 @@
+<?php
+
+declare(strict_types=1);
+
+namespace Evomedien\Vitec\Preview;
+
+use TYPO3\CMS\Backend\Preview\StandardContentPreviewRenderer;
+use TYPO3\CMS\Backend\View\BackendLayout\Grid\GridColumnItem;
+use TYPO3\CMS\Core\Database\Connection;
+use TYPO3\CMS\Core\Database\ConnectionPool;
+use TYPO3\CMS\Core\Service\FlexFormService;
+use TYPO3\CMS\Core\Utility\GeneralUtility;
+
+/**
+ * Collapsible page-module previews for the three sub-market plugin sections
+ * (Olli's wish 2026-10-02: every section collapsible, content visible):
+ *
+ *   vitec_usecaselist    -> selected story titles (+ "no quote" flag)
+ *   vitec_productfeature -> the featured product's title
+ *   vitec_productlist    -> hand-picked product titles / category info
+ *
+ * One class for all three - they only differ in how the FlexForm selection
+ * is resolved to titles.
+ */
+class SubmarketPluginPreview extends StandardContentPreviewRenderer
+{
+    public function renderPageModulePreviewContent(GridColumnItem $item): string
+    {
+        $record = $this->recordArray($item);
+        $flexFormData = GeneralUtility::makeInstance(FlexFormService::class)
+            ->convertFlexFormContentToArray((string)($record['pi_flexform'] ?? ''));
+        $settings = $flexFormData['settings'] ?? [];
+
+        $label = '';
+        $hint = '';
+        $items = [];
+        switch ((string)$record['CType']) {
+            case 'vitec_usecaselist':
+                $layout = (string)($settings['layout'] ?? 'grid');
+                $label = $layout === 'testimonials' ? 'Testimonials' : 'Success Stories';
+                $uids = GeneralUtility::intExplode(',', (string)($settings['usecases'] ?? ''), true);
+                foreach ($this->rows('tx_vitec_domain_model_usecase', $uids, ['quote']) as $row) {
+                    $items[] = $row['title'] . (trim((string)$row['quote']) === '' ? ' — ⚠ kein Zitat' : '');
+                }
+                $hint = $uids === [] ? 'alle Stories (' . $layout . ')' : count($items) . ' ausgewählt · ' . $layout;
+                break;
+            case 'vitec_productfeature':
+                $label = 'Featured Product';
+                $uid = (int)($settings['product'] ?? 0);
+                foreach ($this->rows('tx_vitec_domain_model_product', $uid > 0 ? [$uid] : []) as $row) {
+                    $items[] = $row['title'];
+                }
+                $hint = $items[0] ?? '⚠ kein Produkt gewählt';
+                break;
+            case 'vitec_productlist':
+                $label = 'Products';
+                $uids = GeneralUtility::intExplode(',', (string)($settings['selectedproducts'] ?? ''), true);
+                if ($uids !== []) {
+                    foreach ($this->rows('tx_vitec_domain_model_product', $uids) as $row) {
+                        $items[] = $row['title'];
+                    }
+                    $hint = count($items) . ' handverlesen';
+                } else {
+                    $hint = !empty($settings['allproducts']) ? 'alle Produkte' : 'nach Kategorie';
+                }
+                break;
+        }
+
+        // v14: StandaloneView was removed - views come from the ViewFactory.
+        $view = GeneralUtility::makeInstance(\TYPO3\CMS\Core\View\ViewFactoryInterface::class)
+            ->create(new \TYPO3\CMS\Core\View\ViewFactoryData(
+                templatePathAndFilename: 'EXT:vitec/Resources/Private/Templates/Preview/SubmarketSection.html',
+                request: $GLOBALS['TYPO3_REQUEST'] ?? null,
+            ));
+        $view->assignMultiple([
+            'label' => $label,
+            'hint' => $hint,
+            'items' => $items,
+            'header' => (string)($record['header'] ?? ''),
+        ]);
+        return $view->render();
+    }
+
+    /**
+     * Title rows for the given uids, in the given order.
+     *
+     * @param int[] $uids
+     * @param string[] $extraFields
+     * @return array<int,array<string,mixed>>
+     */
+    private function rows(string $table, array $uids, array $extraFields = []): array
+    {
+        if ($uids === []) {
+            return [];
+        }
+        $queryBuilder = GeneralUtility::makeInstance(ConnectionPool::class)->getQueryBuilderForTable($table);
+        $rows = $queryBuilder->select('uid', 'title', ...$extraFields)->from($table)
+            ->where(
+                $queryBuilder->expr()->in('uid', $queryBuilder->createNamedParameter($uids, Connection::PARAM_INT_ARRAY)),
+                $queryBuilder->expr()->eq('deleted', 0)
+            )
+            ->executeQuery()->fetchAllAssociative();
+        $byUid = array_column($rows, null, 'uid');
+        $ordered = [];
+        foreach ($uids as $uid) {
+            if (isset($byUid[$uid])) {
+                $ordered[] = $byUid[$uid];
+            }
+        }
+        return $ordered;
+    }
+
+    /**
+     * v14: GridColumnItem::getRecord() returns a Domain\Record object, no
+     * longer an array (found 2026-10-02 - crashed the page module preview).
+     * Normalizes both shapes to the raw database array.
+     *
+     * @return array<string,mixed>
+     */
+    private function recordArray(GridColumnItem $item): array
+    {
+        $record = $item->getRecord();
+        if ($record instanceof \TYPO3\CMS\Core\Domain\Record) {
+            $raw = $record->getRawRecord();
+            return $raw !== null ? $raw->toArray() : [];
+        }
+        return (array)$record;
+    }
+}

packages/vitec/Classes/Preview/UsecaseshowPluginPreview.php

@@ -8,7 +8,6 @@ use TYPO3\CMS\Backend\Preview\StandardContentPreviewRenderer;
 use TYPO3\CMS\Backend\View\BackendLayout\Grid\GridColumnItem;
 use TYPO3\CMS\Core\Service\FlexFormService;
 use TYPO3\CMS\Core\Utility\GeneralUtility;
-use TYPO3\CMS\Fluid\View\StandaloneView;
 use Evomedien\Vitec\Domain\Repository\UsecaseRepository;
 
 /**
@@ -22,10 +21,14 @@ class UsecaseshowPluginPreview extends StandardContentPreviewRenderer
      */
     public function renderPageModulePreviewContent(GridColumnItem $item): string
     {
-        $record = $item->getRecord();
+        $record = $this->recordArray($item);
         
-        $view = GeneralUtility::makeInstance(StandaloneView::class);
-        $view->setTemplatePathAndFilename('EXT:vitec/Resources/Private/Templates/Preview/Usecaseshow.html');
+        // v14: StandaloneView was removed - views come from the ViewFactory.
+        $view = GeneralUtility::makeInstance(\TYPO3\CMS\Core\View\ViewFactoryInterface::class)
+            ->create(new \TYPO3\CMS\Core\View\ViewFactoryData(
+                templatePathAndFilename: 'EXT:vitec/Resources/Private/Templates/Preview/Usecaseshow.html',
+                request: $GLOBALS['TYPO3_REQUEST'] ?? null,
+            ));
 
         // Parse FlexForm data
         $flexFormService = GeneralUtility::makeInstance(FlexFormService::class);
@@ -69,7 +72,7 @@ class UsecaseshowPluginPreview extends StandardContentPreviewRenderer
      */
     public function renderPageModulePreviewHeader(GridColumnItem $item): string
     {
-        $record = $item->getRecord();
+        $record = $this->recordArray($item);
         
         // Parse FlexForm to get usecase info for header
         $flexFormService = GeneralUtility::makeInstance(FlexFormService::class);
@@ -83,4 +86,21 @@ class UsecaseshowPluginPreview extends StandardContentPreviewRenderer
         
         return '<strong>🎯 Usecase Show Plugin</strong> <small style="color: orange;">(No usecase selected)</small>';
     }
+
+    /**
+     * v14: GridColumnItem::getRecord() returns a Domain\Record object, no
+     * longer an array (found 2026-10-02 - crashed the page module preview).
+     * Normalizes both shapes to the raw database array.
+     *
+     * @return array<string,mixed>
+     */
+    private function recordArray(GridColumnItem $item): array
+    {
+        $record = $item->getRecord();
+        if ($record instanceof \TYPO3\CMS\Core\Domain\Record) {
+            $raw = $record->getRawRecord();
+            return $raw !== null ? $raw->toArray() : [];
+        }
+        return (array)$record;
+    }
 }

packages/vitec/Configuration/TCA/Overrides/tt_content.php

@@ -80,6 +80,13 @@ use TYPO3\CMS\Extbase\Utility\ExtensionUtility;
         'One card for a Product, Success Story, Market or Solution — all data from the model.',
         'FILE:EXT:vitec/Configuration/FlexForms/Modelcard.xml'
     );
+    // Collapsible sub-market section previews (2026-10-02)
+    $GLOBALS['TCA']['tt_content']['types']['vitec_usecaselist']['previewRenderer']
+        = \Evomedien\Vitec\Preview\SubmarketPluginPreview::class;
+    $GLOBALS['TCA']['tt_content']['types']['vitec_productfeature']['previewRenderer']
+        = \Evomedien\Vitec\Preview\SubmarketPluginPreview::class;
+    $GLOBALS['TCA']['tt_content']['types']['vitec_productlist']['previewRenderer']
+        = \Evomedien\Vitec\Preview\SubmarketPluginPreview::class;
     $GLOBALS['TCA']['tt_content']['types']['vitec_modelcard']['previewRenderer']
         = \Evomedien\Vitec\Preview\ModelcardPreviewRenderer::class;
 

packages/vitec/ContentBlocks/ContentElements/card/templates/backend-preview.html

@@ -3,7 +3,16 @@
 <f:section name="Content">
 
 <f:asset.css identifier="vitec-backend-preview" href="EXT:vitec/Resources/Public/Css/backend-preview.css"/>
+<f:asset.script identifier="vitec-backend-collapse" src="EXT:vitec/Resources/Public/JavaScript/backend-preview-collapse.js"/>
 
+<details class="vitec-collapse">
+<summary>
+    <f:if condition="{data.image.0}"><f:image image="{data.image.0}" class="vitec-collapse__thumb" width="72c" height="44c" alt=""/></f:if>
+    <span class="vitec-collapse__label">Card</span>
+    <span class="vitec-collapse__hint">{data.header}</span>
+    <f:if condition="{data.layout_variant} == 'flipcard'"><span class="vitec-badge">Flip</span></f:if>
+</summary>
+<div class="vitec-collapse__body">
 <div class="vitec-preview vitec-preview--{data.background_variant}">
 
     <f:comment>Thumbnail: image > icon > placeholder</f:comment>
@@ -151,6 +160,8 @@
     </div>
 
 </div>
+</div>
+</details>
 
 </f:section>
 </html>

packages/vitec/ContentBlocks/ContentElements/intro-paragraph/templates/backend-preview.html

@@ -3,7 +3,14 @@
 <f:section name="Content">
 
 <f:asset.css identifier="vitec-backend-preview" href="EXT:vitec/Resources/Public/Css/backend-preview.css"/>
+<f:asset.script identifier="vitec-backend-collapse" src="EXT:vitec/Resources/Public/JavaScript/backend-preview-collapse.js"/>
 
+<details class="vitec-collapse">
+<summary>
+    <span class="vitec-collapse__label">Intro Paragraph</span>
+    <span class="vitec-collapse__hint">{data.header}</span>
+</summary>
+<div class="vitec-collapse__body">
 <div class="vitec-preview">
     <div class="vitec-preview__body">
         <div class="vitec-preview__label">VITEC · Intro Paragraph</div>
@@ -83,6 +90,8 @@
     </div>
 
 </div>
+</div>
+</details>
 
 </f:section>
 </html>

packages/vitec/ContentBlocks/ContentElements/market-hero/templates/backend-preview.html

@@ -1,12 +1,31 @@
 <html xmlns:f="http://typo3.org/ns/TYPO3/CMS/Fluid/ViewHelpers" data-namespace-typo3-fluid="true">
 <f:layout name="Preview"/>
 <f:section name="Content">
+
 <f:asset.css identifier="vitec-backend-preview" href="EXT:vitec/Resources/Public/Css/backend-preview.css"/>
-<div class="vitec-preview">
-    <div class="vitec-preview__body">
-        <strong>Market Hero</strong> — {data.vitec_subline}
-        <f:if condition="{data.vitec_video_url}"><span> · 🎬 {data.vitec_video_title}</span></f:if>
+<f:asset.script identifier="vitec-backend-collapse" src="EXT:vitec/Resources/Public/JavaScript/backend-preview-collapse.js"/>
+
+<details class="vitec-collapse">
+    <summary>
+        <f:if condition="{data.bgimage.0}">
+            <f:image image="{data.bgimage.0}" class="vitec-collapse__thumb" width="72c" height="44c" alt=""/>
+        </f:if>
+        <span class="vitec-collapse__label">1 · Market Hero</span>
+        <span class="vitec-collapse__hint"><f:format.crop maxCharacters="80">{data.subline}</f:format.crop></span>
+        <f:if condition="{data.video_url}"><span class="vitec-badge">🎬 Video</span></f:if>
+    </summary>
+    <div class="vitec-collapse__body">
+        <p><strong>Subline:</strong> {data.subline}</p>
+        <p><strong>CTA:</strong> <f:if condition="{data.cta_label}"><f:then>{data.cta_label}</f:then><f:else>Get in touch (Default)</f:else></f:if></p>
+        <f:if condition="{data.video_url}">
+            <p><strong>Video:</strong> {data.video_title} — {data.video_url}</p>
+        </f:if>
+        <f:if condition="{data.bgimage.0}">
+            <f:then><f:image image="{data.bgimage.0}" width="280c" alt=""/></f:then>
+            <f:else><p><em>Kein Hintergrundbild — Fallback: dunkler Verlauf.</em></p></f:else>
+        </f:if>
     </div>
-</div>
+</details>
+
 </f:section>
 </html>

packages/vitec/ContentBlocks/ContentElements/market-insights/templates/backend-preview.html

@@ -1,12 +1,28 @@
 <html xmlns:f="http://typo3.org/ns/TYPO3/CMS/Fluid/ViewHelpers" data-namespace-typo3-fluid="true">
 <f:layout name="Preview"/>
 <f:section name="Content">
+
 <f:asset.css identifier="vitec-backend-preview" href="EXT:vitec/Resources/Public/Css/backend-preview.css"/>
-<div class="vitec-preview">
-    <div class="vitec-preview__body">
-        <strong>Market Insights</strong> — <f:format.crop maxCharacters="100">{data.vitec_text1}</f:format.crop>
-        <f:if condition="{data.vitec_video_url}"><span> · 🎬 {data.vitec_video_person}</span></f:if>
+<f:asset.script identifier="vitec-backend-collapse" src="EXT:vitec/Resources/Public/JavaScript/backend-preview-collapse.js"/>
+
+<details class="vitec-collapse">
+    <summary>
+        <f:if condition="{data.video_cover.0}">
+            <f:image image="{data.video_cover.0}" class="vitec-collapse__thumb" width="72c" height="44c" alt=""/>
+        </f:if>
+        <span class="vitec-collapse__label">6 · Industry Insights</span>
+        <span class="vitec-collapse__hint"><f:format.crop maxCharacters="80">{data.text1}</f:format.crop></span>
+        <f:if condition="{data.video_url}"><span class="vitec-badge">🎬 {data.video_person}</span></f:if>
+    </summary>
+    <div class="vitec-collapse__body">
+        <p>{data.text1}</p>
+        <p>{data.text2}</p>
+        <p><strong>CTA:</strong> <f:if condition="{data.cta_label}"><f:then>{data.cta_label} → <f:if condition="{data.cta_target}"><f:then>{data.cta_target}</f:then><f:else>/success-stories</f:else></f:if></f:then><f:else>kein Button</f:else></f:if></p>
+        <f:if condition="{data.video_url}">
+            <p><strong>Video:</strong> {data.video_title} — {data.video_person}, {data.video_role}</p>
+        </f:if>
     </div>
-</div>
+</details>
+
 </f:section>
 </html>

packages/vitec/ContentBlocks/ContentElements/market-intro/templates/backend-preview.html

@@ -1,11 +1,29 @@
 <html xmlns:f="http://typo3.org/ns/TYPO3/CMS/Fluid/ViewHelpers" data-namespace-typo3-fluid="true">
 <f:layout name="Preview"/>
 <f:section name="Content">
+
 <f:asset.css identifier="vitec-backend-preview" href="EXT:vitec/Resources/Public/Css/backend-preview.css"/>
-<div class="vitec-preview">
-    <div class="vitec-preview__body">
-        <strong>Market Intro</strong> — <f:format.crop maxCharacters="120">{data.vitec_intro_text}</f:format.crop>
+<f:asset.script identifier="vitec-backend-collapse" src="EXT:vitec/Resources/Public/JavaScript/backend-preview-collapse.js"/>
+
+<details class="vitec-collapse">
+    <summary>
+        <f:if condition="{data.image.0}">
+            <f:image image="{data.image.0}" class="vitec-collapse__thumb" width="72c" height="44c" alt=""/>
+        </f:if>
+        <span class="vitec-collapse__label">2 · Market Intro</span>
+        <span class="vitec-collapse__hint"><f:format.crop maxCharacters="90">{data.intro_text}</f:format.crop></span>
+    </summary>
+    <div class="vitec-collapse__body">
+        <p>{data.intro_text}</p>
+        <p>
+            <strong>Learn more:</strong> <f:if condition="{data.learnmore_target}"><f:then>{data.learnmore_label} → {data.learnmore_target}</f:then><f:else>kein Button</f:else></f:if>
+            · <strong>Product Portfolio:</strong> <f:if condition="{data.show_portfolio}"><f:then>sichtbar</f:then><f:else>ausgeblendet</f:else></f:if>
+        </p>
+        <f:if condition="{data.image.0}">
+            <f:image image="{data.image.0}" width="280c" alt=""/>
+        </f:if>
     </div>
-</div>
+</details>
+
 </f:section>
 </html>

packages/vitec/Resources/Private/Templates/Preview/SubmarketSection.html

@@ -0,0 +1,30 @@
+<html xmlns:f="http://typo3.org/ns/TYPO3/CMS/Fluid/ViewHelpers" data-namespace-typo3-fluid="true">
+
+<f:asset.css identifier="vitec-backend-preview" href="EXT:vitec/Resources/Public/Css/backend-preview.css"/>
+<f:asset.script identifier="vitec-backend-collapse" src="EXT:vitec/Resources/Public/JavaScript/backend-preview-collapse.js"/>
+
+<details class="vitec-collapse">
+    <summary>
+        <span class="vitec-collapse__label">{label}</span>
+        <span class="vitec-collapse__hint">{hint}</span>
+    </summary>
+    <div class="vitec-collapse__body">
+        <f:if condition="{header}">
+            <p><strong>Überschrift:</strong> {header}</p>
+        </f:if>
+        <f:if condition="{items}">
+            <f:then>
+                <ol style="margin:0.25rem 0 0 1rem; padding:0;">
+                    <f:for each="{items}" as="entry">
+                        <li>{entry}</li>
+                    </f:for>
+                </ol>
+            </f:then>
+            <f:else>
+                <p><em>Keine Einzelauswahl.</em></p>
+            </f:else>
+        </f:if>
+    </div>
+</details>
+
+</html>

packages/vitec/Resources/Public/Css/backend-preview.css

@@ -245,3 +245,86 @@
         display: none;
     }
 }
+
+/* =============================================================
+   Collapsible section previews (sub-market template, 2026-10-02)
+   Same practical effect as the container collapse on Two Columns,
+   built with <details> so it works for ANY element preview.
+   ============================================================= */
+details.vitec-collapse {
+    border-left: 4px solid #26358C;
+    background: var(--typo3-state-default-bg, #f8f9fa);
+    border-radius: 4px;
+}
+details.vitec-collapse > summary {
+    cursor: pointer;
+    padding: 0.6rem 0.75rem;
+    display: flex;
+    gap: 0.75rem;
+    align-items: center;
+    list-style: none;
+    font-size: 0.875rem;
+}
+details.vitec-collapse > summary::-webkit-details-marker { display: none; }
+details.vitec-collapse > summary::before {
+    content: '▸';
+    color: #F47937;
+    transition: transform 0.15s ease;
+    flex: 0 0 auto;
+}
+details.vitec-collapse[open] > summary::before { transform: rotate(90deg); }
+.vitec-collapse__label {
+    font-weight: 700;
+    color: #26358C;
+    white-space: nowrap;
+}
+.vitec-collapse__hint {
+    color: #666;
+    overflow: hidden;
+    text-overflow: ellipsis;
+    white-space: nowrap;
+}
+.vitec-collapse__thumb {
+    width: 72px;
+    height: 44px;
+    object-fit: cover;
+    border-radius: 3px;
+    flex: 0 0 auto;
+}
+.vitec-collapse__body {
+    padding: 0 0.75rem 0.75rem 2.1rem;
+    font-size: 0.875rem;
+}
+.vitec-collapse__body p { margin: 0.25rem 0; }
+.vitec-collapse__body img { max-width: 280px; border-radius: 3px; margin-top: 0.4rem; }
+
+/* The page module disables pointer events on preview content so clicks hit
+   the element row - re-enable them inside our collapsible previews, or the
+   summary can never be toggled (found 2026-10-02). */
+details.vitec-collapse,
+details.vitec-collapse * {
+    pointer-events: auto;
+}
+details.vitec-collapse > summary { user-select: none; }
+
+/* =============================================================
+   Collapsible page-module COLUMNS (sub-market sections etc.),
+   container-style: chevron button at the right of the column
+   header, state kept per page+column in localStorage.
+   ============================================================= */
+.t3-page-column-header { position: relative; }
+button.vitec-col-toggle {
+    position: absolute;
+    top: 50%;
+    right: 0.5rem;
+    transform: translateY(-50%);
+    border: 0;
+    background: transparent;
+    cursor: pointer;
+    font-size: 1rem;
+    line-height: 1;
+    color: #F47937;
+    padding: 0.25rem 0.4rem;
+}
+button.vitec-col-toggle:hover { color: #26358C; }
+td.t3-page-column.vitec-col-collapsed > :not(:first-child) { display: none; }

packages/vitec/Resources/Public/JavaScript/backend-preview-collapse.js

@@ -0,0 +1,80 @@
+/**
+ * Collapse toggle for .vitec-collapse previews in the page module.
+ *
+ * Two defenses against the page module's own interaction layer:
+ *  - pointerdown in the CAPTURE phase toggles (fires before any click
+ *    logic TYPO3 registered earlier),
+ *  - the subsequent click on a summary is swallowed so it cannot trigger
+ *    element editing.
+ * Requires pointer-events: auto on the collapse markup (see CSS) - the
+ * module disables pointer events on preview content by default.
+ */
+(function () {
+    function summaryOf(event) {
+        return event.target instanceof Element
+            ? event.target.closest('details.vitec-collapse > summary')
+            : null;
+    }
+    document.addEventListener('pointerdown', function (event) {
+        const summary = summaryOf(event);
+        if (!summary) {
+            return;
+        }
+        event.preventDefault();
+        event.stopImmediatePropagation();
+        const details = summary.parentElement;
+        details.open = !details.open;
+    }, true);
+    document.addEventListener('click', function (event) {
+        if (summaryOf(event)) {
+            event.preventDefault();
+            event.stopImmediatePropagation();
+        }
+    }, true);
+})();
+
+/**
+ * Container-style collapse for whole page-module COLUMNS (the sub-market
+ * section slots and any other backend layout): a chevron button at the
+ * right of each column header folds the column down to its title row.
+ * State is remembered per page + colPos in localStorage.
+ */
+(function () {
+    function storageKey(colPos) {
+        const pageId = new URLSearchParams(window.location.search).get('id') || '0';
+        return 'vitecColCollapse_' + pageId + '_' + colPos;
+    }
+    function apply(column, collapsed, button) {
+        column.classList.toggle('vitec-col-collapsed', collapsed);
+        button.textContent = collapsed ? '▴' : '▾';
+        button.title = collapsed ? 'Section ausklappen' : 'Section einklappen';
+    }
+    function init() {
+        document.querySelectorAll('td.t3-page-column[data-colpos]').forEach(function (column) {
+            const header = column.querySelector('.t3-page-column-header');
+            if (!header || header.querySelector('.vitec-col-toggle')) {
+                return;
+            }
+            const colPos = column.dataset.colpos;
+            const button = document.createElement('button');
+            button.type = 'button';
+            button.className = 'vitec-col-toggle';
+            let collapsed = false;
+            try { collapsed = localStorage.getItem(storageKey(colPos)) === '1'; } catch (e) { /* egal */ }
+            apply(column, collapsed, button);
+            button.addEventListener('click', function (event) {
+                event.preventDefault();
+                event.stopPropagation();
+                const nowCollapsed = !column.classList.contains('vitec-col-collapsed');
+                apply(column, nowCollapsed, button);
+                try { localStorage.setItem(storageKey(colPos), nowCollapsed ? '1' : '0'); } catch (e) { /* egal */ }
+            });
+            header.appendChild(button);
+        });
+    }
+    if (document.readyState === 'loading') {
+        document.addEventListener('DOMContentLoaded', init);
+    } else {
+        init();
+    }
+})();