diff --git a/com_eis/.DS_Store b/com_eis/.DS_Store
index 9e68a39..5a1479c 100644
Binary files a/com_eis/.DS_Store and b/com_eis/.DS_Store differ
diff --git a/com_eis/Archiv.zip b/com_eis/Archiv.zip
index 2083cf4..1a795cc 100644
Binary files a/com_eis/Archiv.zip and b/com_eis/Archiv.zip differ
diff --git a/com_eis/language/.DS_Store b/com_eis/language/.DS_Store
index 2f0642a..58951d7 100644
Binary files a/com_eis/language/.DS_Store and b/com_eis/language/.DS_Store differ
diff --git a/com_eis/language/en-GB/en-GB.com_eis.ini b/com_eis/language/en-GB/en-GB.com_eis.ini
index 69c1898..b1a830b 100644
--- a/com_eis/language/en-GB/en-GB.com_eis.ini
+++ b/com_eis/language/en-GB/en-GB.com_eis.ini
@@ -6,3 +6,4 @@ COM_EIS_MAIN="EIS Hauptansicht"
 COM_EIS_MENU="EIS"
 COM_EIS_CONFIG="Einstellungen"
 COM_EIS_MAINTENANCE="Wartung"
+COM_EIS_PDF_TREE="Verzeichnisbaum"
diff --git a/com_eis/services/provider.php b/com_eis/services/provider.php
index e081340..761779a 100644
--- a/com_eis/services/provider.php
+++ b/com_eis/services/provider.php
@@ -23,7 +23,7 @@ return new class implements ServiceProviderInterface
         $container->registerServiceProvider(new MVCFactory('\\EIS\\Component\\EIS'));
         $container->registerServiceProvider(new RouterFactory('\\EIS\\Component\\EIS'));
 
-        // DownloadController explizit registrieren
+        // Optional: DownloadController explizit registrieren (kann auch weggelassen werden)
         $container->set(
             DownloadController::class,
             fn(Container $c) => new DownloadController()
diff --git a/com_eis/site/.DS_Store b/com_eis/site/.DS_Store
new file mode 100644
index 0000000..6479e22
Binary files /dev/null and b/com_eis/site/.DS_Store differ
diff --git a/com_eis/site/src/.DS_Store b/com_eis/site/src/.DS_Store
new file mode 100644
index 0000000..83806af
Binary files /dev/null and b/com_eis/site/src/.DS_Store differ
diff --git a/com_eis/src/.DS_Store b/com_eis/src/.DS_Store
index de809fd..63835f0 100644
Binary files a/com_eis/src/.DS_Store and b/com_eis/src/.DS_Store differ
diff --git a/com_eis/src/Controller/DisplayController.php b/com_eis/src/Controller/DisplayController.php
index 019c7c7..dd15b78 100644
--- a/com_eis/src/Controller/DisplayController.php
+++ b/com_eis/src/Controller/DisplayController.php
@@ -1,4 +1,5 @@
 <?php
+
 namespace EIS\Component\EIS\Administrator\Controller;
 
 \defined('_JEXEC') or die;
@@ -106,4 +107,35 @@ class DisplayController extends BaseController
             }
         }
     }
+    public function rename(): void
+    {
+        // CSRF prüfen
+        \Joomla\CMS\Session\Session::checkToken() or jexit(\JText::_('JINVALID_TOKEN'));
+
+        $app = \Joomla\CMS\Factory::getApplication();
+        $id = (int) $app->input->get('id');
+        $title = trim((string) $app->input->get('title', '', 'STRING'));
+
+        if ($id <= 0) {
+            $app->enqueueMessage('Ungültige ID', 'error');
+            $this->setRedirect('index.php?option=com_eis&view=main');
+            return;
+        }
+
+        /** @var \Joomla\Database\DatabaseDriver $db */
+        $db = \Joomla\CMS\Factory::getDbo();
+        $query = $db->getQuery(true)
+            ->update($db->quoteName('#__eis_documents'))
+            ->set($db->quoteName('title') . ' = ' . ($title === '' ? 'NULL' : $db->quote($title)))
+            ->where($db->quoteName('id') . ' = ' . (int) $id);
+
+        try {
+            $db->setQuery($query)->execute();
+            $app->enqueueMessage('Anzeigename gespeichert', 'message');
+        } catch (\Throwable $e) {
+            $app->enqueueMessage('Fehler beim Speichern: ' . $e->getMessage(), 'error');
+        }
+
+        $this->setRedirect('index.php?option=com_eis&view=main');
+    }
 }
diff --git a/com_eis/src/Helper/TreeHelper.php b/com_eis/src/Helper/TreeHelper.php
new file mode 100644
index 0000000..ba62edd
--- /dev/null
+++ b/com_eis/src/Helper/TreeHelper.php
@@ -0,0 +1,112 @@
+<?php
+
+namespace EIS\Component\EIS\Administrator\Helper;
+
+\defined('_JEXEC') or die;
+
+use Joomla\CMS\Factory;
+use Joomla\Database\DatabaseDriver;
+
+class TreeHelper
+{
+    /** Lädt #__eis_documents, gruppiert nach parent_id und sortiert */
+    public static function getItems(): array
+    {
+        /** @var DatabaseDriver $db */
+        $db = Factory::getDbo();
+
+        $query = $db->getQuery(true)
+            ->select('*')
+            ->from($db->quoteName('#__eis_documents'))
+            ->order($db->quoteName('ordering') . ' ASC');
+
+        $rows = $db->setQuery($query)->loadAssocList();
+
+        $grouped = [];
+        foreach ($rows as $row) {
+            $pid = $row['parent_id'] === null ? null : (int) $row['parent_id'];
+            $grouped[$pid][] = $row;
+        }
+
+        // alphabetisch nach name
+        foreach ($grouped as &$group) {
+            usort($group, fn($a, $b) => strcasecmp($a['name'], $b['name']));
+        }
+
+        return $grouped;
+    }
+
+    /** Baum rendern (nutzt title als alternativen Anzeigenamen) */
+    public static function renderTree(array $items, ?int $parentId = null): string
+    {
+        if (!isset($items[$parentId])) {
+            return '';
+        }
+
+        $html = '<ul class="pdf-tree">';
+
+        foreach ($items[$parentId] as $item) {
+            $isFolder = (bool) $item['is_folder'];
+            $rawName  = $item['title'] ?: $item['name'];
+            $display  = preg_replace('/\.pdf$/i', '', (string) $rawName);
+            $display  = htmlspecialchars($display, ENT_QUOTES, 'UTF-8');
+            $id       = (int) $item['id'];
+            if ($isFolder) {
+                $fileCount = self::countFilesRecursive($items, $id);
+
+                $html .= '<li class="folder"'
+                    .  ' data-id="' . $id . '"'
+                    .  ' data-title="' . htmlspecialchars((string)($item['title'] ?? ''), ENT_QUOTES, 'UTF-8') . '"'
+                    .  ' data-name="'  . htmlspecialchars((string)$item['name'], ENT_QUOTES, 'UTF-8') . '"'
+                    .  '>';
+                $html .= '<span class="toggle" role="button" aria-label="Ordner umschalten" tabindex="0">▶</span> ';
+                $html .= '<span class="folder-label">📁 ' . $display . ' <small class="count">(' . (int)$fileCount . ')</small></span>';
+                $html .= self::renderTree($items, $id);
+                $html .= '</li>';
+            } else {
+                $sizeStr = '';
+                if (!empty($item['path']) && is_file($item['path'])) {
+                    $size = @filesize($item['path']);
+                    if ($size !== false) {
+                        $sizeStr = ' <small class="meta">(' . self::formatFileSize((int) $size) . ')</small>';
+                    }
+                }
+
+                $html .= '<li class="file"'
+                    .  ' data-id="' . $id . '"'
+                    .  ' data-title="' . htmlspecialchars((string)($item['title'] ?? ''), ENT_QUOTES, 'UTF-8') . '"'
+                    .  ' data-name="'  . htmlspecialchars((string)$item['name'], ENT_QUOTES, 'UTF-8') . '"'
+                    .  '>';
+                $html .= '<span class="file-label">📄 ' . $display . $sizeStr . '</span>';
+                $html .= '</li>';
+            }
+        }
+
+        $html .= '</ul>';
+        return $html;
+    }
+
+    private static function countFilesRecursive(array $items, int $parentId): int
+    {
+        $count = 0;
+        if (!isset($items[$parentId])) {
+            return 0;
+        }
+        foreach ($items[$parentId] as $item) {
+            if ((bool) $item['is_folder']) {
+                $count += self::countFilesRecursive($items, (int)$item['id']);
+            } else {
+                $count++;
+            }
+        }
+        return $count;
+    }
+
+    private static function formatFileSize(int $bytes): string
+    {
+        if ($bytes >= 1073741824) return number_format($bytes / 1073741824, 2) . ' GB';
+        if ($bytes >= 1048576)    return number_format($bytes / 1048576, 1) . ' MB';
+        if ($bytes >= 1024)       return number_format($bytes / 1024, 0) . ' KB';
+        return $bytes . ' B';
+    }
+}
diff --git a/com_eis/src/View/.DS_Store b/com_eis/src/View/.DS_Store
index 264a6c7..d3f08b2 100644
Binary files a/com_eis/src/View/.DS_Store and b/com_eis/src/View/.DS_Store differ
diff --git a/com_eis/src/View/Main/HtmlView.php b/com_eis/src/View/Main/HtmlView.php
index 4637434..d1eb580 100644
--- a/com_eis/src/View/Main/HtmlView.php
+++ b/com_eis/src/View/Main/HtmlView.php
@@ -1,15 +1,20 @@
 <?php
+
 namespace EIS\Component\EIS\Administrator\View\Main;
 
 \defined('_JEXEC') or die;
-use Joomla\CMS\Factory;
+
 use Joomla\CMS\MVC\View\HtmlView as BaseHtmlView;
+use EIS\Component\EIS\Administrator\Helper\TreeHelper;
+
 class HtmlView extends BaseHtmlView
 {
     public function display($tpl = null): void
     {
-        echo "<h2>Willkommen bei EIS</h2>";
-        $this->data = Factory::getApplication()->getUserState('com_eis.pdfdata');
+        // Baumdaten laden und fürs Template bereitstellen
+        $items = TreeHelper::getItems();
+        $this->treeHtml = TreeHelper::renderTree($items);
+
         parent::display($tpl);
     }
 }
diff --git a/com_eis/tmpl/.DS_Store b/com_eis/tmpl/.DS_Store
index ad922eb..be3cf99 100644
Binary files a/com_eis/tmpl/.DS_Store and b/com_eis/tmpl/.DS_Store differ
diff --git a/com_eis/tmpl/main/default.php b/com_eis/tmpl/main/default.php
index 55a7148..7ecccf5 100644
--- a/com_eis/tmpl/main/default.php
+++ b/com_eis/tmpl/main/default.php
@@ -4,41 +4,231 @@
 use Joomla\CMS\HTML\HTMLHelper;
 use Joomla\CMS\Router\Route;
 use Joomla\CMS\Language\Text;
-use Joomla\CMS\Session\Session;
-
 ?>
 
+<!-- Scan-Formular -->
 <form action="<?php echo Route::_('index.php?option=com_eis&task=display.scan'); ?>" method="post" name="adminForm" id="adminForm">
-    <div class="form-horizontal">
-        <fieldset class="adminform">
-            <legend><?php echo Text::_('COM_EIS_DOCUMENT_PATH'); ?></legend>
+  <div class="form-horizontal">
+    <fieldset class="adminform">
+      <legend><?php echo Text::_('COM_EIS_DOCUMENT_PATH'); ?></legend>
+      <!-- Optional: Hier später Pfad aus Einstellungen anzeigen -->
+    </fieldset>
 
-        </fieldset>
-    <div>
-            <button class="btn btn-primary" type="submit"><?php echo Text::_('COM_EIS_SCAN_DOCUMENTS'); ?></button>
-        </div>
+    <div class="mt-2">
+      <button class="btn btn-primary" type="submit">
+        <?php echo Text::_('COM_EIS_SCAN_DOCUMENTS'); ?>
+      </button>
     </div>
-    <?php echo HTMLHelper::_('form.token'); ?>
+  </div>
+  <?php echo HTMLHelper::_('form.token'); ?>
 </form>
-<?php if (!empty($this->data)) : ?>
-    <hr>
-    <h3><?php echo Text::_('COM_EIS_PDF_TREE'); ?></h3>
-    <ul>
-        <?php echo renderTree($this->data); ?>
-    </ul>
-<?php endif; ?>
 
-<?php
-function renderTree($items)
-{
-    $html = '';
-    foreach ($items as $item) {
-        if (isset($item['children'])) {
-            $html .= '<li><strong>' . htmlspecialchars($item['name']) . '</strong><ul>' . renderTree($item['children']) . '</ul></li>';
-        } else {
-            $html .= '<li>' . htmlspecialchars($item['name']) . '</li>';
-        }
+<hr>
+
+<?php $hasTree = !empty($this->treeHtml); ?>
+
+<?php if (!$hasTree): ?>
+  <p class="text-muted">
+    <?php echo Text::_('COM_EIS_NO_DOCUMENTS_FOUND') ?: 'Noch keine Dokumente in der Datenbank. Bitte zuerst „Dokumente einlesen“ ausführen.'; ?>
+  </p>
+<?php else: ?>
+
+  <style>
+    /* Layout */
+    .eis-flex {
+      display: flex;
+      gap: 1rem;
+      align-items: flex-start;
     }
-    return $html;
-}
-?>
\ No newline at end of file
+
+    .eis-tree-wrap {
+      flex: 1 1 auto;
+      background: #f9f9f9;
+      border: 1px solid #ddd;
+      border-radius: 6px;
+      padding: 1em;
+    }
+
+    .eis-edit {
+      flex: 0 0 360px;
+      background: #fff;
+      border: 1px solid #ddd;
+      border-radius: 6px;
+      padding: 1em;
+    }
+
+    .eis-edit h4 {
+      margin-top: 0;
+    }
+
+    /* Baum */
+    .pdf-tree {
+      list-style: none;
+      margin: 0;
+      padding: 0;
+    }
+
+    .pdf-tree ul {
+      list-style: none;
+      margin-left: 1.5em;
+      padding: 0;
+      display: none;
+    }
+
+    /* Unterebenen eingeklappt */
+    .pdf-tree li {
+      margin: .3em 0;
+    }
+
+    .folder>.toggle {
+      cursor: pointer;
+      width: 1em;
+      display: inline-block;
+      user-select: none;
+    }
+
+    .folder>.folder-label,
+    .file>.file-label {
+      cursor: pointer;
+      user-select: none;
+    }
+
+    .pdf-tree .meta {
+      color: #666;
+    }
+
+    .pdf-tree .count {
+      color: #999;
+    }
+
+    /* Steuerleiste */
+    .controls {
+      margin-bottom: .75em;
+    }
+
+    .controls button {
+      margin-right: .5em;
+    }
+  </style>
+
+  <h3 class="mt-3"><?php echo Text::_('COM_EIS_PDF_TREE') ?: 'PDF-Baum'; ?></h3>
+
+  <div class="eis-flex">
+
+    <!-- Linke Seite: Baum -->
+    <div class="eis-tree-wrap">
+      <div class="controls">
+        <button id="eis-expand-all" type="button" class="btn btn-sm btn-secondary">
+          <?php echo Text::_('JGLOBAL_EXPAND_ALL') ?: 'Ausklappen'; ?>
+        </button>
+        <button id="eis-collapse-all" type="button" class="btn btn-sm btn-secondary">
+          <?php echo Text::_('JGLOBAL_COLLAPSE_ALL') ?: 'Einklappen'; ?>
+        </button>
+      </div>
+
+      <div class="tree">
+        <?php echo $this->treeHtml; ?>
+      </div>
+    </div>
+
+    <!-- Rechte Seite: Inline-Bearbeitungsformular -->
+    <div class="eis-edit">
+      <h4><?php echo Text::_('COM_EIS_EDIT_TITLE') ?: 'Anzeigename bearbeiten'; ?></h4>
+      <form action="<?php echo Route::_('index.php?option=com_eis&task=display.rename'); ?>" method="post" id="eis-rename-form">
+        <div class="control-group">
+          <label for="eis-current-name"><?php echo Text::_('COM_EIS_FIELD_NAME') ?: 'Originalname'; ?></label>
+          <input type="text" id="eis-current-name" class="form-control" value="" readonly>
+        </div>
+
+        <div class="control-group" style="margin-top:.5rem;">
+          <label for="eis-title"><?php echo Text::_('COM_EIS_FIELD_TITLE') ?: 'Anzeigename (optional)'; ?></label>
+          <input type="text" name="title" id="eis-title" class="form-control" value="" placeholder="<?php echo Text::_('COM_EIS_PLACEHOLDER_TITLE') ?: 'Leer lassen = automatisch aus Dateiname'; ?>">
+        </div>
+
+        <input type="hidden" name="id" id="eis-id" value="">
+
+        <div style="margin-top:.75rem;">
+          <button type="submit" class="btn btn-success">
+            <?php echo Text::_('JSAVE') ?: 'Speichern'; ?>
+          </button>
+          <button type="button" id="eis-clear-title" class="btn btn-light">
+            <?php echo Text::_('JDEFAULT') ?: 'Zurücksetzen'; ?>
+          </button>
+        </div>
+
+        <?php echo HTMLHelper::_('form.token'); ?>
+      </form>
+    </div>
+  </div>
+
+  <script>
+    document.addEventListener('DOMContentLoaded', function() {
+      const wrap = document.querySelector('.eis-tree-wrap');
+      const form = document.getElementById('eis-rename-form');
+      const idField = document.getElementById('eis-id');
+      const nameField = document.getElementById('eis-current-name');
+      const titleField = document.getElementById('eis-title');
+      const clearBtn = document.getElementById('eis-clear-title');
+
+      if (!wrap || !form) return;
+
+      // Einzelnes Toggle: Caret ODER Label
+      wrap.addEventListener('click', (e) => {
+        const t = e.target;
+
+        // Toggle (Caret oder Label für Ordner)
+        if (t.classList.contains('toggle') || t.classList.contains('folder-label')) {
+          const li = t.closest('li.folder');
+          if (li) {
+            // direkte Kind-UL finden
+            let childUl = null;
+            for (const el of li.children) {
+              if (el.tagName === 'UL') {
+                childUl = el;
+                break;
+              }
+            }
+            if (childUl) {
+              const open = childUl.style.display === 'block';
+              childUl.style.display = open ? 'none' : 'block';
+              const caret = li.querySelector(':scope > .toggle') || li.querySelector('.toggle');
+              if (caret) caret.textContent = open ? '▶' : '▼';
+            }
+          }
+        }
+
+        // Auswahl fürs Bearbeiten: Klick auf Ordner- oder Datei-Label
+        if (t.classList.contains('folder-label') || t.classList.contains('file-label')) {
+          const li = t.closest('li');
+          if (!li) return;
+
+          const id = li.getAttribute('data-id') || '';
+          const title = li.getAttribute('data-title') || '';
+          const name = li.getAttribute('data-name') || '';
+
+          idField.value = id;
+          nameField.value = name;
+          titleField.value = title;
+          titleField.focus();
+        }
+      });
+
+      // "Zurücksetzen" = Anzeigename löschen (fällt auf Dateiname zurück)
+      clearBtn?.addEventListener('click', () => {
+        titleField.value = '';
+        titleField.focus();
+      });
+
+      // Global: Alle aus-/einklappen
+      document.getElementById('eis-expand-all')?.addEventListener('click', () => {
+        document.querySelectorAll('.pdf-tree ul').forEach(ul => ul.style.display = 'block');
+        document.querySelectorAll('.pdf-tree .toggle').forEach(t => t.textContent = '▼');
+      });
+      document.getElementById('eis-collapse-all')?.addEventListener('click', () => {
+        document.querySelectorAll('.pdf-tree ul').forEach(ul => ul.style.display = 'none');
+        document.querySelectorAll('.pdf-tree .toggle').forEach(t => t.textContent = '▶');
+      });
+    });
+  </script>
+
+<?php endif; ?>
\ No newline at end of file