diff --git a/src/edit_backpack.php b/src/edit_backpack.php
index 249eeff..b7be59d 100644
--- a/src/edit_backpack.php
+++ b/src/edit_backpack.php
@@ -30,6 +30,11 @@ $check_col = $conn->query("SHOW COLUMNS FROM backpacks LIKE 'product_url'");
 if ($check_col && $check_col->num_rows == 0) {
     $conn->query("ALTER TABLE backpacks ADD COLUMN product_url VARCHAR(255) DEFAULT NULL AFTER image_url");
 }
+$check_col_cat = $conn->query("SHOW COLUMNS FROM backpacks LIKE 'category_id'");
+if ($check_col_cat && $check_col_cat->num_rows == 0) {
+    $conn->query("ALTER TABLE backpacks ADD COLUMN category_id INT DEFAULT NULL");
+    $conn->query("ALTER TABLE backpacks ADD CONSTRAINT fk_bp_category FOREIGN KEY (category_id) REFERENCES categories(id) ON DELETE SET NULL");
+}
 $check_col_c = $conn->query("SHOW COLUMNS FROM backpack_compartments LIKE 'linked_article_id'");
 if ($check_col_c && $check_col_c->num_rows == 0) {
     $conn->query("ALTER TABLE backpack_compartments ADD COLUMN linked_article_id INT DEFAULT NULL");
@@ -103,14 +108,7 @@ if ($backpack_id > 0) {
     }
 }
 
-// Load Manufacturers
-$stmt_man_load = $conn->prepare("SELECT id, name FROM manufacturers WHERE user_id = ? ORDER BY name ASC");
-$stmt_man_load->bind_param("i", $user_id);
-$stmt_man_load->execute();
-$manufacturers = $stmt_man_load->get_result()->fetch_all(MYSQLI_ASSOC);
-$stmt_man_load->close();
-
-// Load Articles for Linked Compartments
+// Load Manufacturers & Categories
 $hh_ids = [$user_id];
 if ($household_id) {
     $stmt_hhm = $conn->prepare("SELECT id FROM users WHERE household_id = ?");
@@ -121,6 +119,22 @@ if ($household_id) {
 }
 $placeholders = implode(',', array_fill(0, count($hh_ids), '?'));
 $types_hh = str_repeat('i', count($hh_ids));
+
+// Manufacturers
+$stmt_man_load = $conn->prepare("SELECT id, name FROM manufacturers WHERE user_id IN ($placeholders) ORDER BY name ASC");
+$stmt_man_load->bind_param($types_hh, ...$hh_ids);
+$stmt_man_load->execute();
+$manufacturers = $stmt_man_load->get_result()->fetch_all(MYSQLI_ASSOC);
+$stmt_man_load->close();
+
+// Categories
+$stmt_cat_load = $conn->prepare("SELECT id, name FROM categories WHERE user_id IN ($placeholders) ORDER BY name ASC");
+$stmt_cat_load->bind_param($types_hh, ...$hh_ids);
+$stmt_cat_load->execute();
+$categories = $stmt_cat_load->get_result()->fetch_all(MYSQLI_ASSOC);
+$stmt_cat_load->close();
+
+// Load Articles for Linked Compartments
 $stmt_arts = $conn->prepare("SELECT id, name, weight_grams, image_url FROM articles WHERE user_id IN ($placeholders) OR household_id = ? ORDER BY name ASC");
 $params_arts = array_merge($hh_ids, [$household_id ?: 0]); 
 $types_arts = $types_hh . 'i';
@@ -134,6 +148,7 @@ $stmt_arts->close();
 if ($_SERVER['REQUEST_METHOD'] == 'POST') {
     $name = trim($_POST['name']);
     
+    // Manufacturer Logic
     $manufacturer = '';
     if (isset($_POST['manufacturer_select'])) {
         if ($_POST['manufacturer_select'] === 'new') {
@@ -169,6 +184,7 @@ if ($_SERVER['REQUEST_METHOD'] == 'POST') {
     $volume = intval($_POST['volume_liters']);
     $share_household = isset($_POST['share_household']) ? 1 : 0;
     $product_url_input = trim($_POST['product_url'] ?? '');
+    $category_id = !empty($_POST['category_id']) ? intval($_POST['category_id']) : NULL;
     
     $image_url_for_db = $image_url;
     $pasted_image = $_POST['pasted_image_data'] ?? '';
@@ -194,12 +210,12 @@ if ($_SERVER['REQUEST_METHOD'] == 'POST') {
     $final_household_id = ($share_household && $household_id) ? $household_id : NULL;
 
     if ($backpack_id > 0) {
-        $stmt = $conn->prepare("UPDATE backpacks SET name=?, manufacturer=?, model=?, weight_grams=?, volume_liters=?, household_id=?, image_url=?, product_url=? WHERE id=? AND user_id=?");
-        $stmt->bind_param("sssiisssii", $name, $manufacturer, $model, $weight, $volume, $final_household_id, $image_url_for_db, $product_url_input, $backpack_id, $user_id);
+        $stmt = $conn->prepare("UPDATE backpacks SET name=?, manufacturer=?, model=?, weight_grams=?, volume_liters=?, household_id=?, image_url=?, product_url=?, category_id=? WHERE id=? AND user_id=?");
+        $stmt->bind_param("sssiisssiii", $name, $manufacturer, $model, $weight, $volume, $final_household_id, $image_url_for_db, $product_url_input, $category_id, $backpack_id, $user_id);
         $stmt->execute();
     } else {
-        $stmt = $conn->prepare("INSERT INTO backpacks (user_id, household_id, name, manufacturer, model, weight_grams, volume_liters, image_url, product_url) VALUES (?, ?, ?, ?, ?, ?, ?, ?, ?)");
-        $stmt->bind_param("iisssiiss", $user_id, $final_household_id, $name, $manufacturer, $model, $weight, $volume, $image_url_for_db, $product_url_input);
+        $stmt = $conn->prepare("INSERT INTO backpacks (user_id, household_id, name, manufacturer, model, weight_grams, volume_liters, image_url, product_url, category_id) VALUES (?, ?, ?, ?, ?, ?, ?, ?, ?, ?)");
+        $stmt->bind_param("iisssiissi", $user_id, $final_household_id, $name, $manufacturer, $model, $weight, $volume, $image_url_for_db, $product_url_input, $category_id);
         $stmt->execute();
         $backpack_id = $stmt->insert_id;
     }
@@ -309,6 +325,19 @@ require_once 'header.php';
                                             <input type="text" name="new_manufacturer_name" class="form-control form-control-sm" placeholder="Name des neuen Herstellers">
                                         </div>
                                     </div>
+                                    <div class="col-md-6">
+                                        <label class="form-label">Kategorie</label>
+                                        <select class="form-select" id="category_id" name="category_id">
+                                            <option value="">-- Keine (Sonstiges) --</option>
+                                            <?php 
+                                            $current_cat = $backpack['category_id'] ?? 0;
+                                            foreach ($categories as $cat): 
+                                                $selected = ($cat['id'] == $current_cat) ? 'selected' : '';
+                                            ?>
+                                                <option value="<?php echo $cat['id']; ?>" <?php echo $selected; ?>><?php echo htmlspecialchars($cat['name']); ?></option>
+                                            <?php endforeach; ?>
+                                        </select>
+                                    </div>
                                     <div class="col-md-6">
                                         <label class="form-label">Modell</label>
                                         <input type="text" name="model" class="form-control" value="<?php echo htmlspecialchars($backpack['model'] ?? ''); ?>">
@@ -368,7 +397,7 @@ require_once 'header.php';
                                             </select>
                                             
                                             <!-- Text Input -->
-                                            <input type="text" name="comp_names[]" class="form-control name-input" placeholder="Fachname">
+                                            <input type="text" name="comp_names[]" class="form-control name-input" value="Hauptfach" placeholder="Fachname">
                                             
                                             <!-- Article Select -->
                                             <div class="flex-grow-1 article-select-wrapper" style="display:none;">
@@ -456,6 +485,11 @@ document.addEventListener('DOMContentLoaded', function() {
         manSelect.addEventListener('change', function() { toggleManContainer(this.value); });
         new TomSelect(manSelect, { create: false, sortField: { field: "text", direction: "asc" }, onChange: function(value) { toggleManContainer(value); } });
     }
+    
+    // New: Category Select
+    if (document.getElementById('category_id')) {
+        new TomSelect('#category_id', { create: false, sortField: { field: "text", direction: "asc" } });
+    }
 
     const container = document.getElementById('compartments-container');
     
@@ -601,4 +635,4 @@ document.addEventListener('DOMContentLoaded', function() {
 });
 </script>
 
-<?php require_once 'footer.php'; ?>
+<?php require_once 'footer.php'; ?>
\ No newline at end of file
diff --git a/src/packing_list_detail.php b/src/packing_list_detail.php
index f41796c..e26dfaf 100644
--- a/src/packing_list_detail.php
+++ b/src/packing_list_detail.php
@@ -60,13 +60,14 @@ $stmt_list_owner->close();
 
 $page_title = "Packliste: " . htmlspecialchars($packing_list['name']);
 
+// FIX: Join Categories also for Backpacks
 $sql = "SELECT 
             pli.id, pli.quantity, pli.parent_packing_list_item_id, pli.carrier_user_id,
             pli.backpack_id, pli.backpack_compartment_id,
             COALESCE(a.name, pli.name, bp.name, bpc.name, 'Unbekanntes Item') AS article_name,
             COALESCE(a.weight_grams, bp.weight_grams, 0) as weight_grams,
             a.image_url, a.product_designation, a.consumable,
-            c.name AS category_name, 
+            COALESCE(c.name, c_bp.name, 'Sonstiges') AS category_name, 
             m.name AS manufacturer_name, 
             u.username AS carrier_name,
             u.id AS carrier_id
@@ -75,6 +76,7 @@ $sql = "SELECT
         LEFT JOIN backpacks AS bp ON pli.backpack_id = bp.id
         LEFT JOIN backpack_compartments AS bpc ON pli.backpack_compartment_id = bpc.id
         LEFT JOIN categories AS c ON a.category_id = c.id 
+        LEFT JOIN categories AS c_bp ON bp.category_id = c_bp.id
         LEFT JOIN manufacturers AS m ON a.manufacturer_id = m.id 
         LEFT JOIN users AS u ON pli.carrier_user_id = u.id 
         WHERE pli.packing_list_id = ?
@@ -394,19 +396,30 @@ function render_item_row($item, $level, $items_by_parent) {
 const carrierStatsData = <?php echo json_encode($carrier_stats_details); ?>;
 
 document.addEventListener('DOMContentLoaded', function() {
-    // Tooltip logic
+    // Tooltip logic with EVENT DELEGATION
     const tooltip = document.getElementById('image-preview-tooltip');
     if (tooltip) {
-        document.querySelectorAll('.article-image-trigger').forEach(trigger => {
-            trigger.addEventListener('mouseover', e => {
+        document.body.addEventListener('mouseover', function(e) {
+            if (e.target.classList.contains('article-image-trigger')) {
                 const url = e.target.getAttribute('data-preview-url');
                 if (url && !url.endsWith('assets/images/keinbild.png')) { 
                     tooltip.style.backgroundImage = `url('${url}')`; 
                     tooltip.style.display = 'block'; 
                 }
-            });
-            trigger.addEventListener('mousemove', e => { tooltip.style.left = e.pageX + 15 + 'px'; tooltip.style.top = e.pageY + 15 + 'px'; });
-            trigger.addEventListener('mouseout', () => { tooltip.style.display = 'none'; });
+            }
+        });
+        
+        document.body.addEventListener('mousemove', function(e) {
+            if (tooltip.style.display === 'block') {
+                tooltip.style.left = e.pageX + 15 + 'px';
+                tooltip.style.top = e.pageY + 15 + 'px';
+            }
+        });
+        
+        document.body.addEventListener('mouseout', function(e) {
+            if (e.target.classList.contains('article-image-trigger')) {
+                tooltip.style.display = 'none';
+            }
         });
     }
     const tooltipTriggerList = [].slice.call(document.querySelectorAll('[data-bs-toggle="tooltip"]'));