diff --git a/CHANGELOG.md b/CHANGELOG.md
index db9a0b1..d1f2d63 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -1,5 +1,55 @@
 # Changelog
 
+## Changes 10/25/2025 (v1.6.7)
+
+release(v1.6.7): Folder Move feature, stable DnD persistence, safer uploads, and ACL/UI polish
+
+### 📂 Folder Move (new major feature)
+
+**Drag & Drop to move folder, use context menu or Move Folder button**  
+
+- Added **Move Folder** support across backend and UI.  
+  - New API endpoint: `public/api/folder/moveFolder.php`  
+  - Controller and ACL updates to validate scope, ownership, and permissions.  
+  - Non-admins can only move within folders they own.  
+  - `ACL::renameTree()` re-keys all subtree ACLs on folder rename/move.  
+- Introduced new capabilities:
+  - `canMoveFolder`
+  - `canMove` (UI alias for backward compatibility)
+- New “Move Folder” button + modal in the UI with full i18n strings (`i18n.js`).  
+- Action button styling and tooltip consistency for all folder actions.
+
+### 🧱 Drag & Drop / Layout Improvements
+
+- Fixed **random sidebar → top zone jumps** on refresh.  
+- Cards/panels now **persist exactly where you placed them** (`userZonesSnapshot`)  
+  — no unwanted repositioning unless the window is resized below the small-screen threshold.
+- Added hysteresis around the 1205 px breakpoint to prevent flicker when resizing.  
+- Eliminated the 50 px “ghost” gutter with `clampSidebarWhenEmpty()`:
+  - Sidebar no longer reserves space when collapsed or empty.  
+  - Temporarily “unclamps” during drag so drop targets remain accurate and full-width.  
+- Removed forced 800 px height on drag highlight; uses natural flex layout now.  
+- General layout polish — smoother transitions when toggling *Hide/Show Panels*.
+
+### ☁️ Uploads & UX
+
+- Stronger folder sanitization and safer base-path handling.  
+- Fixed subfolder creation when uploading directories (now builds under correct parent).  
+- Improved chunk error handling and metadata key correctness.  
+- Clearer success/failure toasts and accurate filename display from server responses.
+
+### 🔐 Permissions / ACL
+
+- Simplified file rename checks — now rely solely on granular `ACL::canRename()`.  
+- Updated capability lists to include move/rename operations consistently.
+
+### 🌐 UI / i18n Enhancements
+
+- Added i18n strings for new “Move Folder” prompts, modals, and tooltips.  
+- Minor UI consistency tweaks: button alignment, focus states, reduced-motion support.  
+
+---
+
 ## Changes 10/24/2025 (v1.6.6)
 
 release(v1.6.6): header-mounted toggle, dark-mode polish, persistent layout, and ACL fix
diff --git a/public/api/folder/capabilities.php b/public/api/folder/capabilities.php
index 4952bd0..3f75b1d 100644
--- a/public/api/folder/capabilities.php
+++ b/public/api/folder/capabilities.php
@@ -185,6 +185,7 @@ $canDelete   = $gDeleteBase   && !$readOnly && $inScope;
 $canReceive  = ($gUploadBase || $gCreateBase || $canManageBase) && !$readOnly && $inScope;
 // Back-compat: expose as canMoveIn (used by toolbar/context-menu/drag&drop)
 $canMoveIn   = $canReceive;
+$canMoveAlias = $canMoveIn;
 $canEdit     = $gEditBase     && !$readOnly && $inScope;
 $canCopy     = $gCopyBase     && !$readOnly && $inScope;
 $canExtract  = $gExtractBase  && !$readOnly && $inScope;
@@ -200,6 +201,12 @@ if ($isRoot) {
   $canRename = false;
   $canDelete = false;
   $canShareFoldEff = false;
+  $canMoveFolder = false;
+}
+
+if (!$isRoot) {
+  $canMoveFolder = (ACL::canManage($username, $perms, $folder) || ACL::isOwner($username, $perms, $folder))
+                   && !$readOnly;
 }
 
 $owner = null;
@@ -225,6 +232,8 @@ echo json_encode([
   'canRename'    => $canRename,
   'canDelete'    => $canDelete,
   'canMoveIn'    => $canMoveIn,
+  'canMove'       => $canMoveAlias, 
+  'canMoveFolder'=> $canMoveFolder,
   'canEdit'      => $canEdit,
   'canCopy'      => $canCopy,
   'canExtract'   => $canExtract,
diff --git a/public/api/folder/moveFolder.php b/public/api/folder/moveFolder.php
new file mode 100644
index 0000000..a259abf
--- /dev/null
+++ b/public/api/folder/moveFolder.php
@@ -0,0 +1,9 @@
+<?php
+// public/api/folder/moveFolder.php
+declare(strict_types=1);
+
+require_once __DIR__ . '/../../../config/config.php';
+require_once PROJECT_ROOT . '/src/controllers/FolderController.php';
+
+$controller = new FolderController();
+$controller->moveFolder();
diff --git a/public/css/styles.css b/public/css/styles.css
index 686f699..d125d36 100644
--- a/public/css/styles.css
+++ b/public/css/styles.css
@@ -1046,11 +1046,6 @@ label {
   display: none;
 }
 
-#createFolderBtn {
-  margin-top: 0px !important;
-  height: 40px !important;
-  font-size: 1rem;
-}
 
 .folder-actions {
   display: flex;
@@ -1058,6 +1053,7 @@ label {
   padding-left: 8px;
   align-items: center;
   white-space: nowrap;
+  padding-top: 10px;
 }
 
 @media (min-width: 600px) and (max-width: 992px) {
@@ -1066,6 +1062,70 @@ label {
   }
 }
 
+.folder-actions .btn {
+  padding: 10px 12px;
+  font-size: 0.85rem;
+  line-height: 1.1;
+  border-radius: 6px;
+}
+
+.folder-actions .material-icons {
+  font-size: 24px;
+  vertical-align: -2px; 
+}
+
+.folder-actions .btn + .btn {
+  margin-left: 6px;
+}
+
+.folder-actions .btn {
+  padding: 10px 12px;
+  font-size: 0.85rem;
+  line-height: 1.1;
+  border-radius: 6px;
+
+  transform: scale(1);
+  transform-origin: center;
+  transition: transform 120ms ease, box-shadow 120ms ease;
+  will-change: transform;
+}
+
+
+.folder-actions .material-icons {
+  font-size: 24px;
+  vertical-align: -2px;
+  transition: transform 120ms ease;
+}
+
+.folder-actions .btn:hover,
+.folder-actions .btn:focus-visible {
+  transform: scale(1.06);
+  box-shadow: 0 2px 8px rgba(0,0,0,0.12);
+}
+
+.folder-actions .btn:hover .material-icons,
+.folder-actions .btn:focus-visible .material-icons {
+  transform: scale(1.05);
+}
+
+.folder-actions .btn:focus-visible {
+  outline: 2px solid rgba(33,150,243,0.6);
+  outline-offset: 2px;
+}
+
+@media (prefers-reduced-motion: reduce) {
+  .folder-actions .btn,
+  .folder-actions .material-icons {
+    transition: none;
+  }
+}
+
+#moveFolderBtn {
+  background-color: #ff9800;
+  border-color: #ff9800;
+  color: #fff;
+}
+
 .row-selected {
   background-color: #f2f2f2 !important;
 }
diff --git a/public/index.html b/public/index.html
index 533c996..567ebac 100644
--- a/public/index.html
+++ b/public/index.html
@@ -286,9 +286,27 @@
                           </div>
                         </div>
                       </div>
+                      <button id="moveFolderBtn" class="btn btn-warning ml-2" data-i18n-title="move_folder">
+                        <i class="material-icons">drive_file_move</i>
+                      </button>
+                      <!-- MOVE FOLDER MODAL (place near your other folder modals) -->
+                      <div id="moveFolderModal" class="modal" style="display:none;">
+                        <div class="modal-content">
+                          <h4 data-i18n-key="move_folder_title">Move Folder</h4>
+                          <p data-i18n-key="move_folder_message">Select a destination folder to move the current folder
+                            into:</p>
+                          <select id="moveFolderTarget" class="form-control modal-input"></select>
+                          <div class="modal-footer" style="margin-top:15px; text-align:right;">
+                            <button id="cancelMoveFolder" class="btn btn-secondary"
+                              data-i18n-key="cancel">Cancel</button>
+                            <button id="confirmMoveFolder" class="btn btn-primary" data-i18n-key="move">Move</button>
+                          </div>
+                        </div>
+                      </div>
                       <button id="renameFolderBtn" class="btn btn-warning ml-2" data-i18n-title="rename_folder">
                         <i class="material-icons">drive_file_rename_outline</i>
                       </button>
+
                       <div id="renameFolderModal" class="modal">
                         <div class="modal-content">
                           <h4 data-i18n-key="rename_folder_title">Rename Folder</h4>
@@ -391,14 +409,12 @@
               data-i18n-key="download_zip">Download ZIP</button>
             <button id="extractZipBtn" class="btn action-btn btn-sm btn-info" data-i18n-title="extract_zip"
               data-i18n-key="extract_zip_button">Extract Zip</button>
-              <div id="createDropdown" class="dropdown-container" style="position:relative; display:inline-block;">
-                <button id="createBtn"  class="btn action-btn" data-i18n-key="create">
-                  ${t('create')} <span class="material-icons" style="font-size:16px;vertical-align:middle;">arrow_drop_down</span>
-                </button>
-                <ul
-                  id="createMenu"
-                  class="dropdown-menu"
-                  style="
+            <div id="createDropdown" class="dropdown-container" style="position:relative; display:inline-block;">
+              <button id="createBtn" class="btn action-btn" data-i18n-key="create">
+                ${t('create')} <span class="material-icons"
+                  style="font-size:16px;vertical-align:middle;">arrow_drop_down</span>
+              </button>
+              <ul id="createMenu" class="dropdown-menu" style="
                     display: none;
                     position: absolute;
                     top: 100%;
@@ -411,27 +427,23 @@
                     box-shadow: 0 2px 6px rgba(0,0,0,0.2);
                     z-index: 1000;
                     min-width: 140px;
-                  "
-                >
-                  <li id="createFileOption" class="dropdown-item" data-i18n-key="create_file" style="padding:8px 12px; cursor:pointer;">
-                    ${t('create_file')}
-                  </li>
-                  <li id="createFolderOption" class="dropdown-item" data-i18n-key="create_folder" style="padding:8px 12px; cursor:pointer;">
-                    ${t('create_folder')}
-                  </li>
-                </ul>
-              </div>
+                  ">
+                <li id="createFileOption" class="dropdown-item" data-i18n-key="create_file"
+                  style="padding:8px 12px; cursor:pointer;">
+                  ${t('create_file')}
+                </li>
+                <li id="createFolderOption" class="dropdown-item" data-i18n-key="create_folder"
+                  style="padding:8px 12px; cursor:pointer;">
+                  ${t('create_folder')}
+                </li>
+              </ul>
+            </div>
             <!-- Create File Modal -->
             <div id="createFileModal" class="modal" style="display:none;">
               <div class="modal-content">
                 <h4 data-i18n-key="create_new_file">Create New File</h4>
-                <input
-                  type="text"
-                  id="createFileNameInput"
-                  class="form-control"
-                  placeholder="Enter filename…"
-                  data-i18n-placeholder="newfile_placeholder"
-                />
+                <input type="text" id="createFileNameInput" class="form-control" placeholder="Enter filename…"
+                  data-i18n-placeholder="newfile_placeholder" />
                 <div class="modal-footer" style="margin-top:1rem; text-align:right;">
                   <button id="cancelCreateFile" class="btn btn-secondary" data-i18n-key="cancel">Cancel</button>
                   <button id="confirmCreateFile" class="btn btn-primary" data-i18n-key="create">Create</button>
diff --git a/public/js/adminPanel.js b/public/js/adminPanel.js
index 8447471..8ed377c 100644
--- a/public/js/adminPanel.js
+++ b/public/js/adminPanel.js
@@ -59,7 +59,7 @@ function onShareFileToggle(row, checked) {
 }
 
 function onWriteToggle(row, checked) {
-  const caps = ["create","upload","edit","rename","copy","move","delete","extract"];
+  const caps = ["create","upload","edit","rename","copy","delete","extract"];
   caps.forEach(c => {
     const box = qs(row, `input[data-cap="${c}"]`);
     if (box) box.checked = checked;
@@ -683,25 +683,32 @@ function renderFolderGrantsUI(username, container, folders, grants) {
   // toolbar
   const toolbar = document.createElement('div');
   toolbar.className = 'folder-access-toolbar';
-  toolbar.innerHTML = `
-    <input type="text" class="form-control" style="max-width:220px;" placeholder="${tf('search_folders', 'Search folders')}" />
-    <label class="muted" title="${tf('view_all_help', 'See all files in this folder (everyone’s files)')}">
-      <input type="checkbox" data-bulk="view" /> ${tf('view_all', 'View (all)')}
-    </label>
-    <label class="muted" title="${tf('view_own_help', 'See only files you uploaded in this folder')}">
-      <input type="checkbox" data-bulk="viewOwn" /> ${tf('view_own', 'View (own)')}
-    </label>
-    <label class="muted" title="${tf('write_help', 'Create/upload files and edit/rename/copy/delete items in this folder')}">
-      <input type="checkbox" data-bulk="write" /> ${tf('write_full', 'Write (upload/edit/delete)')}
-    </label>
-    <label class="muted" title="${tf('manage_help', 'Owner-level: can grant access; implies View (all)/Create Folder/Rename Folder/Move Files/Share Folder')}">
-      <input type="checkbox" data-bulk="manage" /> ${tf('manage', 'Manage')}
-    </label>
-    <label class="muted" title="${tf('share_help', 'Create/manage share links; implies View (all)')}">
-      <input type="checkbox" data-bulk="share" /> ${tf('share', 'Share')}
-    </label>
-    <span class="muted">(${tf('applies_to_filtered', 'applies to filtered list')})</span>
-  `;
+toolbar.innerHTML = `
+  <input type="text" class="form-control" style="max-width:220px;"
+         placeholder="${tf('search_folders', 'Search folders')}" />
+
+  <label class="muted" title="${tf('view_all_help', 'See all files in this folder (everyone’s files)')}">
+    <input type="checkbox" data-bulk="view" /> ${tf('view_all', 'View (all)')}
+  </label>
+
+  <label class="muted" title="${tf('view_own_help', 'See only files you uploaded in this folder')}">
+    <input type="checkbox" data-bulk="viewOwn" /> ${tf('view_own', 'View (own files)')}
+  </label>
+
+  <label class="muted" title="${tf('write_help', 'File-level: upload, edit, rename, copy, delete, extract ZIPs')}">
+    <input type="checkbox" data-bulk="write" /> ${tf('write_full', 'Write (file ops)')}
+  </label>
+
+  <label class="muted" title="${tf('manage_help', 'Folder-level (owner): can create/rename/move folders and grant access; implies View (all)')}">
+    <input type="checkbox" data-bulk="manage" /> ${tf('manage', 'Manage (folder owner)')}
+  </label>
+
+  <label class="muted" title="${tf('share_help', 'Create/manage share links; implies View (all)')}">
+    <input type="checkbox" data-bulk="share" /> ${tf('share', 'Share')}
+  </label>
+
+  <span class="muted">(${tf('applies_to_filtered', 'applies to filtered list')})</span>
+`;
   container.appendChild(toolbar);
 
   const list = document.createElement('div');
@@ -709,30 +716,55 @@ function renderFolderGrantsUI(username, container, folders, grants) {
   container.appendChild(list);
 
   const headerHtml = `
-    <div class="folder-access-header">
+  <div class="folder-access-header">
     <div class="folder-cell" title="${tf('folder_help','Folder path within FileRise')}">
       ${tf('folder','Folder')}
     </div>
-    <div class="perm-col" title="${tf('view_all_help', 'See all files in this folder (everyone’s files)')}">${tf('view_all', 'View (all)')}</div>
-    <div class="perm-col" title="${tf('view_own_help', 'See only files you uploaded in this folder')}">${tf('view_own', 'View (own)')}</div>
-    <div class="perm-col" title="${tf('write_help', 'Meta: toggles all write operations (below) on/off for this row')}">${tf('write_full', 'Write')}</div>
-    <div class="perm-col" title="${tf('manage_help', 'Owner-level: can grant access; implies View (all)/Create Folder/Rename Folder/Move Files/Share Folder')}">${tf('manage', 'Manage')}</div>
-    <div class="perm-col" title="${tf('create_help', 'Create empty files')}">${tf('create', 'Create')}</div>
-    <div class="perm-col" title="${tf('upload_help', 'Upload files to this folder')}">${tf('upload', 'Upload')}</div>
-    <div class="perm-col" title="${tf('edit_help', 'Edit file contents')}">${tf('edit', 'Edit')}</div>
-    <div class="perm-col" title="${tf('rename_help', 'Rename files')}">${tf('rename', 'Rename')}</div>
-    <div class="perm-col" title="${tf('copy_help', 'Copy files')}">${tf('copy', 'Copy')}</div>
-    <div class="perm-col" title="${tf('move_help', 'Move files: requires Manage')}">${tf('move', 'Move')}</div>
-    <div class="perm-col" title="${tf('delete_help', 'Delete files/folders')}">${tf('delete', 'Delete')}</div>
-    <div class="perm-col" title="${tf('extract_help', 'Extract ZIP archives')}">${tf('extract', 'Extract ZIP')}</div>
-    <div class="perm-col" title="${tf('share_file_help', 'Create share links for files')}">${tf('share_file', 'Share File')}</div>
-    <div class="perm-col" title="${tf('share_folder_help', 'Create share links for folders (requires View all)')}">${tf('share_folder', 'Share Folder')}</div>
+    <div class="perm-col" title="${tf('view_all_help', 'See all files in this folder (everyone’s files)')}">
+      ${tf('view_all', 'View (all)')}
+    </div>
+    <div class="perm-col" title="${tf('view_own_help', 'See only files you uploaded in this folder')}">
+      ${tf('view_own', 'View (own)')}
+    </div>
+    <div class="perm-col" title="${tf('write_help', 'Meta: toggles all file-level operations below')}">
+      ${tf('write_full', 'Write')}
+    </div>
+    <div class="perm-col" title="${tf('manage_help', 'Folder owner: can create/rename/move folders and grant access; implies View (all)')}">
+      ${tf('manage', 'Manage')}
+    </div>
+    <div class="perm-col" title="${tf('create_help', 'Create empty file')}">
+      ${tf('create', 'Create File')}
+    </div>
+    <div class="perm-col" title="${tf('upload_help', 'Upload a file into this folder')}">
+      ${tf('upload', 'Upload File')}
+    </div>
+    <div class="perm-col" title="${tf('edit_help', 'Edit file contents')}">
+      ${tf('edit', 'Edit File')}
+    </div>
+    <div class="perm-col" title="${tf('rename_help', 'Rename a file')}">
+      ${tf('rename', 'Rename File')}
+    </div>
+    <div class="perm-col" title="${tf('copy_help', 'Copy a file')}">
+      ${tf('copy', 'Copy File')}
+    </div>
+    <div class="perm-col" title="${tf('delete_help', 'Delete a file')}">
+      ${tf('delete', 'Delete File')}
+    </div>
+    <div class="perm-col" title="${tf('extract_help', 'Extract ZIP archives')}">
+      ${tf('extract', 'Extract ZIP')}
+    </div>
+    <div class="perm-col" title="${tf('share_file_help', 'Create share links for files')}">
+      ${tf('share_file', 'Share File')}
+    </div>
+    <div class="perm-col" title="${tf('share_folder_help', 'Create share links for folders (requires Manage + View (all))')}">
+      ${tf('share_folder', 'Share Folder')}
+    </div>
   </div>`;
 
   function rowHtml(folder) {
     const g = grants[folder] || {};
     const name = folder === 'root' ? '(Root)' : folder;
-    const writeMetaChecked = !!(g.create || g.upload || g.edit || g.rename || g.copy || g.move || g.delete || g.extract);
+    const writeMetaChecked = !!(g.create || g.upload || g.edit || g.rename || g.copy || g.delete || g.extract);
     const shareFolderDisabled = !g.view;
     return `
       <div class="folder-access-row" data-folder="${folder}">
@@ -752,7 +784,6 @@ function renderFolderGrantsUI(username, container, folders, grants) {
         <div class="perm-col"><input type="checkbox" data-cap="edit"      ${g.edit ? 'checked' : ''}></div>
         <div class="perm-col"><input type="checkbox" data-cap="rename"    ${g.rename ? 'checked' : ''}></div>
         <div class="perm-col"><input type="checkbox" data-cap="copy"      ${g.copy ? 'checked' : ''}></div>
-        <div class="perm-col"><input type="checkbox" data-cap="move"      ${g.move ? 'checked' : ''}></div>
         <div class="perm-col"><input type="checkbox" data-cap="delete"    ${g.delete ? 'checked' : ''}></div>
         <div class="perm-col"><input type="checkbox" data-cap="extract"   ${g.extract ? 'checked' : ''}></div>
         <div class="perm-col"><input type="checkbox" data-cap="shareFile" ${g.shareFile ? 'checked' : ''}></div>
@@ -788,7 +819,7 @@ function renderFolderGrantsUI(username, container, folders, grants) {
         if (v) v.checked = true;
         if (w) w.checked = true;
         if (vo) { vo.checked = false; vo.disabled = true; }
-        ['create','upload','edit','rename','copy','move','delete','extract','shareFile','shareFolder']
+        ['create','upload','edit','rename','copy','delete','extract','shareFile','shareFolder']
           .forEach(c => { const cb = qs(row, `input[data-cap="${c}"]`); if (cb) cb.checked = true; });
         setRowDisabled(row, true);
         const tag = row.querySelector('.inherited-tag');
@@ -888,7 +919,7 @@ function renderFolderGrantsUI(username, container, folders, grants) {
         const w = r.querySelector('input[data-cap="write"]');
         const vo = r.querySelector('input[data-cap="viewOwn"]');
         const boxes = [
-          'create','upload','edit','rename','copy','move','delete','extract','shareFile','shareFolder'
+          'create','upload','edit','rename','copy','delete','extract','shareFile','shareFolder'
         ].map(c => r.querySelector(`input[data-cap="${c}"]`));
         if (m) m.checked = checked;
         if (v) v.checked = checked;
diff --git a/public/js/dragAndDrop.js b/public/js/dragAndDrop.js
index e5348f6..7af023c 100644
--- a/public/js/dragAndDrop.js
+++ b/public/js/dragAndDrop.js
@@ -8,7 +8,7 @@
 const MEDIUM_MIN = 1205;      // matches your small-screen cutoff
 const MEDIUM_MAX = 1600;      // tweak as you like
 
-const TOGGLE_TOP_PX = 10;
+const TOGGLE_TOP_PX = 8;
 const TOGGLE_LEFT_PX = 100;
 
 const TOGGLE_ICON_OPEN = 'view_sidebar';
@@ -19,6 +19,13 @@ const KNOWN_CARD_IDS = ['uploadCard', 'folderManagementCard'];
 
 const CARD_IDS = ['uploadCard', 'folderManagementCard'];
 
+// --- NEW: separate user snapshot so refresh restores *manual* placements only ---
+const USER_SNAPSHOT_KEY = 'userZonesSnapshot';   // { cardId: 'sidebarDropArea'|'leftCol'|'rightCol' }
+
+function hasUserSnapshot() {
+  try { const s = JSON.parse(localStorage.getItem(USER_SNAPSHOT_KEY) || '{}'); return !!s && Object.keys(s).length > 0; } catch { return false; }
+}
+
 function isDarkMode() {
   return document.body.classList.contains('dark-mode');
 }
@@ -54,6 +61,16 @@ function snapshotZoneLocations() {
   localStorage.setItem('zonesSnapshot', JSON.stringify(snap));
 }
 
+// NEW: Save where the user *manually* placed cards (used on normal refresh).
+function snapshotUserZones() {
+  const snap = {};
+  getKnownCards().forEach(card => {
+    const p = card.parentNode;
+    snap[card.id] = p && p.id ? p.id : '';
+  });
+  localStorage.setItem(USER_SNAPSHOT_KEY, JSON.stringify(snap));
+}
+
 // Move a card to default expanded spot (your request: sidebar is default).
 function moveCardToSidebarDefault(card) {
   const sidebar = getSidebar();
@@ -75,6 +92,56 @@ function stripHeaderArtifacts(card) {
   }
 }
 
+// Kill the 50px ghost gutter when the sidebar isn't participating in layout.
+function clampSidebarWhenEmpty() {
+  const sidebar = getSidebar();
+  if (!sidebar) return;
+
+  const sidebarHasCards = hasSidebarCards();
+  const collapsed = isZonesCollapsed();
+
+  // Sidebar should not take space if it's collapsed OR has no cards.
+  const shouldHideSidebarSpace = collapsed || !sidebarHasCards;
+
+  if (shouldHideSidebarSpace) {
+    // Make sure it takes absolutely no horizontal space.
+    sidebar.style.display   = 'none'; // don't render at all
+    sidebar.style.width     = '0px';
+    sidebar.style.minWidth  = '0px';
+    sidebar.style.margin    = '0';
+    sidebar.style.padding   = '0';
+    sidebar.style.flex      = '0 0 0px';
+
+    // if you add/remove highlight elsewhere, also ensure it's not forcing size
+    sidebar.classList.remove('active');
+  } else {
+    // Let your CSS control it when it's actually visible/has cards.
+    sidebar.style.width     = '';
+    sidebar.style.minWidth  = '';
+    sidebar.style.margin    = '';
+    sidebar.style.padding   = '';
+    sidebar.style.flex      = '';
+    // display is already decided by updateSidebarVisibility/applyZonesCollapsed
+  }
+}
+
+// Let the sidebar become a real drop target during drag, even if empty.
+function unclampSidebarForDrag() {
+  const sidebar = getSidebar();
+  if (!sidebar) return;
+  // only un-clamp if panels are not collapsed
+  if (!isZonesCollapsed()) {
+    sidebar.style.display  = 'block';
+    // give it a sensible min width so the highlight looks right
+    sidebar.style.minWidth = '280px';
+    // never force a fixed height here; let CSS layout handle it
+    sidebar.style.width    = '';
+    sidebar.style.flex     = ''; // don't lock flex while dragging
+    sidebar.style.margin   = '';
+    sidebar.style.padding  = '';
+  }
+}
+
 // Restore cards after “expand” (toggle off) or after refresh.
 // - If we have a snapshot, use it.
 // - If not, put all cards in the sidebar (your default).
@@ -152,8 +219,10 @@ function removeHeaderIconForCard(card) {
   }
 }
 
+// Apply *user* snapshot on normal load (not expand) to preserve manual placement.
 function applySnapshotIfPresent() {
-  const snap = readZonesSnapshot();
+  let snap = {};
+  try { snap = JSON.parse(localStorage.getItem(USER_SNAPSHOT_KEY) || '{}'); } catch { snap = {}; }
   const keys = Object.keys(snap || {});
   if (!keys.length) return false;
 
@@ -231,21 +300,39 @@ function moveAllSidebarCardsToTop() {
 }
 
 // New: enforce responsive behavior (sidebar disabled on small screens)
+// Add hysteresis to avoid flapping near threshold
 let __lastIsSmall = null;
+let __lastWidth = null;
+const SMALL_ENTER = MEDIUM_MIN - 16;  // enter small below this
+const SMALL_EXIT  = MEDIUM_MIN + 16;  // leave small above this
 
 function enforceResponsiveZones() {
-  const isSmall = isSmallScreen();
+  const w = window.innerWidth;
+  const prevSmall = __lastIsSmall;
+  let nowSmall;
+
+  if (__lastWidth == null) {
+    nowSmall = w < MEDIUM_MIN;
+  } else if (prevSmall === true) {
+    nowSmall = !(w >= SMALL_EXIT);
+  } else if (prevSmall === false) {
+    nowSmall = (w < SMALL_ENTER);
+  } else {
+    nowSmall = w < MEDIUM_MIN;
+  }
+  __lastWidth = w;
+
   const sidebar = getSidebar();
   const topZone = getTopZone();
 
-  if (isSmall && __lastIsSmall !== true) {
+  if (nowSmall && prevSmall !== true) {
     // entering small: remember what was in sidebar, move them up, hide sidebar
     snapshotSidebarCardsForResponsive();
     moveAllSidebarCardsToTop();
     if (sidebar) sidebar.style.display = 'none';
     if (topZone) topZone.style.display = ''; // ensure visible
     __lastIsSmall = true;
-  } else if (!isSmall && __lastIsSmall !== false) {
+  } else if (!nowSmall && prevSmall !== false) {
     // leaving small: restore only what used to be in the sidebar
     const ids = readResponsiveSnapshot();
     const sb = getSidebar();
@@ -309,10 +396,10 @@ function setZonesCollapsed(collapsed) {
 
   if (collapsed) {
     // Remember where cards were, then show them as header icons
-    snapshotZoneLocations();
-    collapseCardsToHeader();     // your existing helper that calls insertCardInHeader(...)
+    snapshotZoneLocations();   // original snapshot used only for collapse/expand
+    collapseCardsToHeader();   // your existing helper that calls insertCardInHeader(...)
   } else {
-    // Expand: bring cards back
+    // Expand: bring cards back (from the collapse snapshot)
     restoreCardsFromSnapshot();
 
     // Ensure zones are visible right away after expand
@@ -324,6 +411,7 @@ function setZonesCollapsed(collapsed) {
 
   ensureZonesToggle();
   updateZonesToggleUI();
+  clampSidebarWhenEmpty();
 }
 
 function applyZonesCollapsed() {
@@ -570,6 +658,7 @@ export function loadSidebarOrder() {
   const orderStr = localStorage.getItem('sidebarOrder');
   const headerOrderStr = localStorage.getItem('headerOrder');
 
+  // Restore user's last manual placement on normal load
   if (applySnapshotIfPresent()) {
     updateTopZoneLayout();
     updateSidebarVisibility();
@@ -577,6 +666,23 @@ export function loadSidebarOrder() {
     ensureZonesToggle();
     return;
   }
+  // If no user snapshot exists and we're not on small screens,
+  // but the cards are currently in the top zone, default them to the sidebar once.
+  if (!hasUserSnapshot() && !isSmallScreen() && hasTopZoneCards() && !hasSidebarCards()) {
+    const sb = getSidebar();
+    if (sb) {
+      ['uploadCard','folderManagementCard'].forEach(id => {
+        const c = document.getElementById(id);
+        if (c && !sb.contains(c)) {
+          sb.appendChild(c);
+          c.style.width = '100%';
+        }
+      });
+      snapshotUserZones();      // persist this as the user's baseline
+      updateSidebarVisibility();
+      updateTopZoneLayout();
+    }
+  }
 
   // Only apply the one-time default if *not* initialized yet
   if (!defaultAlready &&
@@ -692,6 +798,7 @@ function updateSidebarVisibility() {
   localStorage.setItem('layoutDefaultApplied_v1', '1');
 
   ensureZonesToggle();
+  clampSidebarWhenEmpty(); 
 }
 
 // NEW: Save header order to localStorage.
@@ -733,6 +840,7 @@ function updateTopZoneLayout() {
 
   // hide whole top row when empty (kills the gap)
   if (topZone) topZone.style.display = (hasUpload || hasFolder) ? '' : 'none';
+  clampSidebarWhenEmpty(); 
 }
 
 // When a card is being dragged, if the top drop zone is empty, set its min-height.
@@ -799,6 +907,10 @@ function insertCardInSidebar(card, event) {
 
   // SAVE order & refresh minimal UI, but DO NOT collapse/restore here:
   saveSidebarOrder();
+
+  // NEW: persist user manual placement (used on normal refresh)
+  snapshotUserZones();
+
   updateSidebarVisibility();
   ensureZonesToggle();
   updateZonesToggleUI();
@@ -1081,13 +1193,15 @@ export function initDragAndDrop() {
             showTopZoneWhileDragging();
 
             const sidebar = getSidebar();
-            if (sidebar) {
-              sidebar.classList.add('active');
-              sidebar.style.display = isZonesCollapsed() ? 'none' : 'block';
-              sidebar.classList.add('highlight');
-              sidebar.style.height = '800px';
-              sidebar.style.minWidth = '280px';
-            }
+if (sidebar) {
+  unclampSidebarForDrag();                // <— NEW
+  sidebar.classList.add('active');
+  sidebar.classList.add('highlight');
+  // keep it visible, but don't force a fixed height
+  sidebar.style.removeProperty('height'); // <— no 800px box
+  // ensure it's actually visible if not collapsed
+  if (!isZonesCollapsed()) sidebar.style.display = 'block';
+}
 
             showHeaderDropZone();
             const topZone = getTopZone();
@@ -1169,7 +1283,6 @@ export function initDragAndDrop() {
           const sidebarElem = getSidebar();
           if (sidebarElem) {
             const rect = sidebarElem.getBoundingClientRect();
-            const dropZoneBottom = rect.top + 800; // Virtual drop zone height.
             if (
               e.clientX >= rect.left &&
               e.clientX <= rect.right &&
@@ -1208,6 +1321,9 @@ export function initDragAndDrop() {
                 setTimeout(() => {
                   card.style.removeProperty('width');
                 }, 210);
+
+                // NEW: persist user manual placement
+                snapshotUserZones();
               }
             }
           }
@@ -1224,6 +1340,7 @@ export function initDragAndDrop() {
             ) {
               insertCardInHeader(card, e);
               droppedInHeader = true;
+              // header mode is transient; do not overwrite userZones here
             }
           }
 
@@ -1257,10 +1374,16 @@ export function initDragAndDrop() {
 
           updateTopZoneLayout();
           updateSidebarVisibility();
+          clampSidebarWhenEmpty();
+          if (sidebar) {
+            sidebar.classList.remove('highlight');
+            sidebar.style.height = '';
+            sidebar.style.minWidth = '';
+          }
           hideHeaderDropZone();
 
           cleanupTopZoneAfterDrop();
-          snapshotZoneLocations();
+          snapshotZoneLocations();   // keep original (collapse/expand)
           const tz = getTopZone();
           if (tz) tz.style.minHeight = '';
         }
diff --git a/public/js/folderManager.js b/public/js/folderManager.js
index 8b0d83d..5251715 100644
--- a/public/js/folderManager.js
+++ b/public/js/folderManager.js
@@ -103,6 +103,7 @@ async function applyFolderCapabilities(folder) {
 
   const isRoot   = (folder === 'root');
   setControlEnabled(document.getElementById('createFolderBtn'), !!caps.canCreate);
+  setControlEnabled(document.getElementById('moveFolderBtn'), !!caps.canMoveFolder);
   setControlEnabled(document.getElementById('renameFolderBtn'), !isRoot && !!caps.canRename);
   setControlEnabled(document.getElementById('deleteFolderBtn'), !isRoot && !!caps.canDelete);
   setControlEnabled(document.getElementById('shareFolderBtn'), !isRoot && !!caps.canShareFolder);
@@ -180,6 +181,49 @@ function breadcrumbDropHandler(e) {
     console.error("Invalid drag data on breadcrumb:", err);
     return;
   }
+  /* FOLDER MOVE FALLBACK */
+  if (!dragData) {
+    const plain = (event.dataTransfer && event.dataTransfer.getData("application/x-filerise-folder")) ||
+                  (event.dataTransfer && event.dataTransfer.getData("text/plain")) || "";
+    if (plain) {
+      const sourceFolder = String(plain).trim();
+      if (sourceFolder && sourceFolder !== "root") {
+        if (dropFolder === sourceFolder || (dropFolder + "/").startsWith(sourceFolder + "/")) {
+          showToast("Invalid destination.", 4000);
+          return;
+        }
+        fetchWithCsrf("/api/folder/moveFolder.php", {
+          method: "POST",
+          headers: { "Content-Type": "application/json" },
+          credentials: "include",
+          body: JSON.stringify({ source: sourceFolder, destination: dropFolder })
+        })
+          .then(safeJson)
+          .then(data => {
+            if (data && !data.error) {
+              showToast(`Folder moved to ${dropFolder}!`);
+              if (window.currentFolder && (window.currentFolder === sourceFolder || window.currentFolder.startsWith(sourceFolder + "/"))) {
+                const base = sourceFolder.split("/").pop();
+                const newPath = (dropFolder === "root" ? "" : dropFolder + "/") + base;
+                window.currentFolder = newPath;
+              }
+              return loadFolderTree().then(() => {
+                try { expandTreePath(window.currentFolder || "root"); } catch (_) {}
+                loadFileList(window.currentFolder || "root");
+              });
+            } else {
+              showToast("Error: " + (data && data.error || "Could not move folder"), 5000);
+            }
+          })
+          .catch(err => {
+            console.error("Error moving folder:", err);
+            showToast("Error moving folder", 5000);
+          });
+      }
+    }
+    return;
+  }
+
   const filesToMove = dragData.files ? dragData.files : (dragData.fileName ? [dragData.fileName] : []);
   if (filesToMove.length === 0) return;
 
@@ -262,7 +306,7 @@ function renderFolderTree(tree, parentPath = "", defaultDisplay = "block") {
     } else {
       html += `<span class="folder-indent-placeholder"></span>`;
     }
-    html += `<span class="folder-option" data-folder="${fullPath}">${escapeHTML(folder)}</span>`;
+    html += `<span class="folder-option" draggable="true" data-folder="${fullPath}">${escapeHTML(folder)}</span>`;
     if (hasChildren) {
       html += renderFolderTree(tree[folder], fullPath, displayState);
     }
@@ -312,13 +356,58 @@ function folderDropHandler(event) {
   event.preventDefault();
   event.currentTarget.classList.remove("drop-hover");
   const dropFolder = event.currentTarget.getAttribute("data-folder");
-  let dragData;
+  let dragData = null;
   try {
-    dragData = JSON.parse(event.dataTransfer.getData("application/json"));
-  } catch (e) {
+    const jsonStr = event.dataTransfer.getData("application/json") || "";
+    if (jsonStr) dragData = JSON.parse(jsonStr);
+  } 
+ catch (e) {
     console.error("Invalid drag data", e);
     return;
   }
+  /* FOLDER MOVE FALLBACK */
+  if (!dragData) {
+    const plain = (event.dataTransfer && event.dataTransfer.getData("application/x-filerise-folder")) ||
+                  (event.dataTransfer && event.dataTransfer.getData("text/plain")) || "";
+    if (plain) {
+      const sourceFolder = String(plain).trim();
+      if (sourceFolder && sourceFolder !== "root") {
+        if (dropFolder === sourceFolder || (dropFolder + "/").startsWith(sourceFolder + "/")) {
+          showToast("Invalid destination.", 4000);
+          return;
+        }
+        fetchWithCsrf("/api/folder/moveFolder.php", {
+          method: "POST",
+          headers: { "Content-Type": "application/json" },
+          credentials: "include",
+          body: JSON.stringify({ source: sourceFolder, destination: dropFolder })
+        })
+          .then(safeJson)
+          .then(data => {
+            if (data && !data.error) {
+              showToast(`Folder moved to ${dropFolder}!`);
+              if (window.currentFolder && (window.currentFolder === sourceFolder || window.currentFolder.startsWith(sourceFolder + "/"))) {
+                const base = sourceFolder.split("/").pop();
+                const newPath = (dropFolder === "root" ? "" : dropFolder + "/") + base;
+                window.currentFolder = newPath;
+              }
+              return loadFolderTree().then(() => {
+                try { expandTreePath(window.currentFolder || "root"); } catch (_) {}
+                loadFileList(window.currentFolder || "root");
+              });
+            } else {
+              showToast("Error: " + (data && data.error || "Could not move folder"), 5000);
+            }
+          })
+          .catch(err => {
+            console.error("Error moving folder:", err);
+            showToast("Error moving folder", 5000);
+          });
+      }
+    }
+    return;
+  }
+
   const filesToMove = dragData.files ? dragData.files : (dragData.fileName ? [dragData.fileName] : []);
   if (filesToMove.length === 0) return;
 
@@ -459,6 +548,14 @@ export async function loadFolderTree(selectedFolder) {
 
     // Attach drag/drop event listeners.
     container.querySelectorAll(".folder-option").forEach(el => {
+      // Provide folder path payload for folder->folder DnD
+      el.addEventListener("dragstart", (ev) => {
+        const src = el.getAttribute("data-folder");
+        try { ev.dataTransfer.setData("application/x-filerise-folder", src); } catch (e) {}
+        try { ev.dataTransfer.setData("text/plain", src); } catch (e) {}
+        ev.dataTransfer.effectAllowed = "move";
+      });
+
       el.addEventListener("dragover", folderDragOverHandler);
       el.addEventListener("dragleave", folderDragLeaveHandler);
       el.addEventListener("drop", folderDropHandler);
@@ -487,6 +584,14 @@ export async function loadFolderTree(selectedFolder) {
 
     // Folder-option click: update selection, breadcrumbs, and file list
     container.querySelectorAll(".folder-option").forEach(el => {
+      // Provide folder path payload for folder->folder DnD
+      el.addEventListener("dragstart", (ev) => {
+        const src = el.getAttribute("data-folder");
+        try { ev.dataTransfer.setData("application/x-filerise-folder", src); } catch (e) {}
+        try { ev.dataTransfer.setData("text/plain", src); } catch (e) {}
+        ev.dataTransfer.effectAllowed = "move";
+      });
+
       el.addEventListener("click", function (e) {
         e.stopPropagation();
         container.querySelectorAll(".folder-option").forEach(item => item.classList.remove("selected"));
@@ -642,6 +747,44 @@ if (submitRename) {
   });
 }
 
+// === Move Folder Modal helper (shared by button + context menu) ===
+function openMoveFolderUI(sourceFolder) {
+  const modal     = document.getElementById('moveFolderModal');
+  const targetSel = document.getElementById('moveFolderTarget');
+
+  // If you right-clicked a different folder than currently selected, use that
+  if (sourceFolder && sourceFolder !== 'root') {
+    window.currentFolder = sourceFolder;
+  }
+
+  // Fill target dropdown
+  if (targetSel) {
+    targetSel.innerHTML = '';
+    fetch('/api/folder/getFolderList.php', { credentials: 'include' })
+      .then(r => r.json())
+      .then(list => {
+        if (Array.isArray(list) && list.length && typeof list[0] === 'object' && list[0].folder) {
+          list = list.map(it => it.folder);
+        }
+        // Root option
+        const rootOpt = document.createElement('option');
+        rootOpt.value = 'root'; rootOpt.textContent = '(Root)';
+        targetSel.appendChild(rootOpt);
+
+        (list || [])
+          .filter(f => f && f !== 'trash' && f !== (window.currentFolder || ''))
+          .forEach(f => {
+            const o = document.createElement('option');
+            o.value = f; o.textContent = f;
+            targetSel.appendChild(o);
+          });
+      })
+      .catch(()=>{ /* no-op */ });
+  }
+
+  if (modal) modal.style.display = 'block';
+}
+
 export function openDeleteFolderModal() {
   const selectedFolder = window.currentFolder || "root";
   if (!selectedFolder || selectedFolder === "root") {
@@ -841,6 +984,10 @@ function folderManagerContextMenuHandler(e) {
         if (input) input.focus();
       }
     },
+    {
+      label: t("move_folder"),
+      action: () => { openMoveFolderUI(folder); }
+    },
     {
       label: t("rename_folder"),
       action: () => { openRenameFolderModal(); }
@@ -923,4 +1070,53 @@ document.addEventListener("DOMContentLoaded", function () {
 });
 
 // Initial context menu delegation bind
-bindFolderManagerContextMenu();
\ No newline at end of file
+bindFolderManagerContextMenu();
+
+document.addEventListener("DOMContentLoaded", () => {
+  const moveBtn   = document.getElementById('moveFolderBtn');
+  const modal     = document.getElementById('moveFolderModal');
+  const targetSel = document.getElementById('moveFolderTarget');
+  const cancelBtn = document.getElementById('cancelMoveFolder');
+  const confirmBtn= document.getElementById('confirmMoveFolder');
+
+  if (moveBtn) {
+    moveBtn.addEventListener('click', () => {
+      const cf = window.currentFolder || 'root';
+      if (!cf || cf === 'root') { showToast('Select a non-root folder to move.'); return; }
+      openMoveFolderUI(cf);
+    });
+  }
+
+  if (cancelBtn) cancelBtn.addEventListener('click', () => { if (modal) modal.style.display = 'none'; });
+
+  if (confirmBtn) confirmBtn.addEventListener('click', async () => {
+    if (!targetSel) return;
+    const destination = targetSel.value;
+    const source      = window.currentFolder;
+
+    if (!destination) { showToast('Pick a destination'); return; }
+    if (destination === source || (destination + '/').startsWith(source + '/')) {
+      showToast('Invalid destination'); return;
+    }
+
+    try {
+      const res = await fetch('/api/folder/moveFolder.php', {
+        method: 'POST', credentials: 'include',
+        headers: { 'Content-Type': 'application/json', 'X-CSRF-Token': window.csrfToken },
+        body: JSON.stringify({ source, destination })
+      });
+      const data = await safeJson(res);
+      if (res.ok && data && !data.error) {
+        showToast('Folder moved');
+        if (modal) modal.style.display='none';
+        await loadFolderTree();
+        const base = source.split('/').pop();
+        const newPath = (destination === 'root' ? '' : destination + '/') + base;
+        window.currentFolder = newPath;
+        loadFileList(window.currentFolder || 'root');
+      } else {
+        showToast('Error: ' + (data && data.error || 'Move failed'));
+      }
+    } catch (e) { console.error(e); showToast('Move failed'); }
+  });
+});
diff --git a/public/js/i18n.js b/public/js/i18n.js
index b1eef29..32335a1 100644
--- a/public/js/i18n.js
+++ b/public/js/i18n.js
@@ -282,7 +282,27 @@ const translations = {
     "bypass_ownership": "Bypass Ownership",
     "error_loading_user_grants": "Error loading user grants",
     "click_to_edit": "Click to edit",
-    "folder_access": "Folder Access"
+    "folder_access": "Folder Access",
+    "move_folder": "Move Folder",
+    "move_folder_message": "Select a destination folder to move this folder to:",
+    "move_folder_title": "Move this folder",
+    "move_folder_success": "Folder moved successfully.",
+    "move_folder_error": "Error moving folder.",
+    "move_folder_invalid": "Invalid source or destination folder.",
+    "move_folder_denied": "You do not have permission to move this folder.",
+    "move_folder_same_dest": "Destination cannot be the source or one of its subfolders.",
+    "move_folder_same_owner": "Source and destination must have the same owner.",
+    "move_folder_confirm": "Are you sure you want to move this folder?",
+    "move_folder_select_dest": "Select a destination folder",
+    "move_folder_select_dest_help": "Choose where this folder should be moved to.",
+    "acl_move_folder_label": "Move Folder (source)",
+    "acl_move_folder_help": "Allows moving this folder to a different parent. Requires Manage or Ownership on the folder.",
+    "acl_move_in_label": "Allow Moves Into This Folder (destination)",
+    "acl_move_in_help": "Allows items or folders from elsewhere to be moved into this folder. Requires Manage on the destination folder.",
+    "acl_move_folder_info": "Moving folders is restricted to folder owners or managers. Destination folders must also allow moves in.",
+    "context_move_folder": "Move Folder...",
+    "context_move_here": "Move Here",
+    "context_move_cancel": "Cancel Move"
   },
   es: {
     "please_log_in_to_continue": "Por favor, inicie sesión para continuar.",
diff --git a/public/js/upload.js b/public/js/upload.js
index 4d4a9af..c1d8a36 100644
--- a/public/js/upload.js
+++ b/public/js/upload.js
@@ -161,91 +161,91 @@ function createFileEntry(file) {
   const removeBtn = document.createElement("button");
   removeBtn.classList.add("remove-file-btn");
   removeBtn.textContent = "×";
-// In your remove button event listener, replace the fetch call with:
-removeBtn.addEventListener("click", function (e) {
-  e.stopPropagation();
-  const uploadIndex = file.uploadIndex;
-  window.selectedFiles = window.selectedFiles.filter(f => f.uploadIndex !== uploadIndex);
-  
-  // Cancel the file upload if possible.
-  if (typeof file.cancel === "function") {
-    file.cancel();
-    console.log("Canceled file upload:", file.fileName);
-  }
-  
-  // Remove file from the resumable queue.
-  if (resumableInstance && typeof resumableInstance.removeFile === "function") {
-    resumableInstance.removeFile(file);
-  }
-  
-  // Call our helper repeatedly to remove the chunk folder.
-  if (file.uniqueIdentifier) {
-    removeChunkFolderRepeatedly(file.uniqueIdentifier, window.csrfToken, 3, 1000);
-  }
-  
-  li.remove();
-  updateFileInfoCount();
-});
+  // In your remove button event listener, replace the fetch call with:
+  removeBtn.addEventListener("click", function (e) {
+    e.stopPropagation();
+    const uploadIndex = file.uploadIndex;
+    window.selectedFiles = window.selectedFiles.filter(f => f.uploadIndex !== uploadIndex);
+
+    // Cancel the file upload if possible.
+    if (typeof file.cancel === "function") {
+      file.cancel();
+      console.log("Canceled file upload:", file.fileName);
+    }
+
+    // Remove file from the resumable queue.
+    if (resumableInstance && typeof resumableInstance.removeFile === "function") {
+      resumableInstance.removeFile(file);
+    }
+
+    // Call our helper repeatedly to remove the chunk folder.
+    if (file.uniqueIdentifier) {
+      removeChunkFolderRepeatedly(file.uniqueIdentifier, window.csrfToken, 3, 1000);
+    }
+
+    li.remove();
+    updateFileInfoCount();
+  });
   li.removeBtn = removeBtn;
   li.appendChild(removeBtn);
 
   // Add pause/resume/restart button if the file supports pause/resume.
-// Conditionally add the pause/resume button only if file.pause is available
-// Pause/Resume button (for resumable file–picker uploads)
-if (typeof file.pause === "function") {
-  const pauseResumeBtn = document.createElement("button");
-  pauseResumeBtn.setAttribute("type", "button"); // not a submit button
-  pauseResumeBtn.classList.add("pause-resume-btn");
-  // Start with pause icon and disable button until upload starts
-  pauseResumeBtn.innerHTML = '<span class="material-icons pauseResumeBtn">pause_circle_outline</span>';
-  pauseResumeBtn.disabled = true; 
-  pauseResumeBtn.addEventListener("click", function (e) {
-    e.stopPropagation();
-    if (file.isError) {
-      // If the file previously failed, try restarting upload.
-      if (typeof file.retry === "function") {
-        file.retry();
-        file.isError = false;
-        pauseResumeBtn.innerHTML = '<span class="material-icons pauseResumeBtn">pause_circle_outline</span>';
-      }
-    } else if (!file.paused) {
-      // Pause the upload (if possible)
-      if (typeof file.pause === "function") {
-        file.pause();
-        file.paused = true;
-        pauseResumeBtn.innerHTML = '<span class="material-icons pauseResumeBtn">play_circle_outline</span>';
-      } else {
-      }
-    } else if (file.paused) {
-      // Resume sequence: first call to resume (or upload() fallback)
-      if (typeof file.resume === "function") {
-        file.resume();
-      } else {
-        resumableInstance.upload();
-      }
-      // After a short delay, pause again then resume
-      setTimeout(() => {
+  // Conditionally add the pause/resume button only if file.pause is available
+  // Pause/Resume button (for resumable file–picker uploads)
+  if (typeof file.pause === "function") {
+    const pauseResumeBtn = document.createElement("button");
+    pauseResumeBtn.setAttribute("type", "button"); // not a submit button
+    pauseResumeBtn.classList.add("pause-resume-btn");
+    // Start with pause icon and disable button until upload starts
+    pauseResumeBtn.innerHTML = '<span class="material-icons pauseResumeBtn">pause_circle_outline</span>';
+    pauseResumeBtn.disabled = true;
+    pauseResumeBtn.addEventListener("click", function (e) {
+      e.stopPropagation();
+      if (file.isError) {
+        // If the file previously failed, try restarting upload.
+        if (typeof file.retry === "function") {
+          file.retry();
+          file.isError = false;
+          pauseResumeBtn.innerHTML = '<span class="material-icons pauseResumeBtn">pause_circle_outline</span>';
+        }
+      } else if (!file.paused) {
+        // Pause the upload (if possible)
         if (typeof file.pause === "function") {
           file.pause();
+          file.paused = true;
+          pauseResumeBtn.innerHTML = '<span class="material-icons pauseResumeBtn">play_circle_outline</span>';
+        } else {
+        }
+      } else if (file.paused) {
+        // Resume sequence: first call to resume (or upload() fallback)
+        if (typeof file.resume === "function") {
+          file.resume();
         } else {
           resumableInstance.upload();
         }
+        // After a short delay, pause again then resume
         setTimeout(() => {
-          if (typeof file.resume === "function") {
-            file.resume();
+          if (typeof file.pause === "function") {
+            file.pause();
           } else {
             resumableInstance.upload();
           }
+          setTimeout(() => {
+            if (typeof file.resume === "function") {
+              file.resume();
+            } else {
+              resumableInstance.upload();
+            }
+          }, 100);
         }, 100);
-      }, 100);
-      file.paused = false;
-      pauseResumeBtn.innerHTML = '<span class="material-icons pauseResumeBtn">pause_circle_outline</span>';
-    } else {
-      console.error("Pause/resume function not available for file", file);
-    }
-  });
-  li.appendChild(pauseResumeBtn);
-}
+        file.paused = false;
+        pauseResumeBtn.innerHTML = '<span class="material-icons pauseResumeBtn">pause_circle_outline</span>';
+      } else {
+        console.error("Pause/resume function not available for file", file);
+      }
+    });
+    li.appendChild(pauseResumeBtn);
+  }
 
   // Preview element
   const preview = document.createElement("div");
@@ -406,20 +406,27 @@ let resumableInstance;
 function initResumableUpload() {
   resumableInstance = new Resumable({
     target: "/api/upload/upload.php",
-    query: { folder: window.currentFolder || "root", upload_token: window.csrfToken },
-    chunkSize: 1.5 * 1024 * 1024, // 1.5 MB chunks
+    chunkSize: 1.5 * 1024 * 1024,
     simultaneousUploads: 3,
     forceChunkSize: true,
     testChunks: false,
-    throttleProgressCallbacks: 1,
     withCredentials: true,
     headers: { 'X-CSRF-Token': window.csrfToken },
-    query: {
+    query: () => ({
       folder: window.currentFolder || "root",
-      upload_token: window.csrfToken   // still as a fallback
-    }
+      upload_token: window.csrfToken
+    })
   });
 
+  // keep query fresh when folder changes (call this from your folder nav code)
+  function updateResumableQuery() {
+    if (!resumableInstance) return;
+    resumableInstance.opts.headers['X-CSRF-Token'] = window.csrfToken;
+    // if you're not using a function for query, do:
+    resumableInstance.opts.query.folder = window.currentFolder || 'root';
+    resumableInstance.opts.query.upload_token = window.csrfToken;
+  }
+
   const fileInput = document.getElementById("file");
   if (fileInput) {
     // Assign Resumable to file input for file picker uploads.
@@ -432,6 +439,7 @@ function initResumableUpload() {
   }
 
   resumableInstance.on("fileAdded", function (file) {
+
     // Initialize custom paused flag
     file.paused = false;
     file.uploadIndex = file.uniqueIdentifier;
@@ -461,16 +469,17 @@ function initResumableUpload() {
     li.dataset.uploadIndex = file.uniqueIdentifier;
     list.appendChild(li);
     updateFileInfoCount();
+    updateResumableQuery();
   });
 
-  resumableInstance.on("fileProgress", function(file) {
+  resumableInstance.on("fileProgress", function (file) {
     const progress = file.progress(); // value between 0 and 1
     const percent = Math.floor(progress * 100);
     const li = document.querySelector(`li.upload-progress-item[data-upload-index="${file.uniqueIdentifier}"]`);
     if (li && li.progressBar) {
       if (percent < 99) {
         li.progressBar.style.width = percent + "%";
-        
+
         // Calculate elapsed time and speed.
         const elapsed = (Date.now() - li.startTime) / 1000;
         let speed = "";
@@ -491,7 +500,7 @@ function initResumableUpload() {
         li.progressBar.style.width = "100%";
         li.progressBar.innerHTML = '<i class="material-icons spinning" style="vertical-align: middle;">autorenew</i>';
       }
-      
+
       // Enable the pause/resume button once progress starts.
       const pauseResumeBtn = li.querySelector(".pause-resume-btn");
       if (pauseResumeBtn) {
@@ -499,8 +508,8 @@ function initResumableUpload() {
       }
     }
   });
-  
-  resumableInstance.on("fileSuccess", function(file, message) {
+
+  resumableInstance.on("fileSuccess", function (file, message) {
     // Try to parse JSON response
     let data;
     try {
@@ -508,18 +517,18 @@ function initResumableUpload() {
     } catch (e) {
       data = null;
     }
-  
+
     // 1) Soft‐fail CSRF? then update token & retry this file
     if (data && data.csrf_expired) {
       // Update global and Resumable headers
       window.csrfToken = data.csrf_token;
       resumableInstance.opts.headers['X-CSRF-Token'] = data.csrf_token;
-      resumableInstance.opts.query.upload_token        = data.csrf_token;
+      resumableInstance.opts.query.upload_token = data.csrf_token;
       // Retry this chunk/file
       file.retry();
-      return; 
+      return;
     }
-  
+
     // 2) Otherwise treat as real success:
     const li = document.querySelector(
       `li.upload-progress-item[data-upload-index="${file.uniqueIdentifier}"]`
@@ -531,13 +540,13 @@ function initResumableUpload() {
       const pauseResumeBtn = li.querySelector(".pause-resume-btn");
       if (pauseResumeBtn) pauseResumeBtn.style.display = "none";
       const removeBtn = li.querySelector(".remove-file-btn");
-      if (removeBtn)   removeBtn.style.display = "none";
+      if (removeBtn) removeBtn.style.display = "none";
       setTimeout(() => li.remove(), 5000);
     }
-  
+
     loadFileList(window.currentFolder);
   });
-  
+
 
 
   resumableInstance.on("fileError", function (file, message) {
@@ -637,7 +646,7 @@ function submitFiles(allFiles) {
       } catch (e) {
         jsonResponse = null;
       }
-    
+
       // ─── Soft-fail CSRF: retry this upload ───────────────────────
       if (jsonResponse && jsonResponse.csrf_expired) {
         console.warn("CSRF expired during upload, retrying chunk", file.uploadIndex);
@@ -650,10 +659,10 @@ function submitFiles(allFiles) {
         xhr.send(formData);
         return;  // skip the "finishedCount++" and error/success logic for now
       }
-    
+
       // ─── Normal success/error handling ────────────────────────────  
       const li = progressElements[file.uploadIndex];
-    
+
       if (xhr.status >= 200 && xhr.status < 300 && (!jsonResponse || !jsonResponse.error)) {
         // real success
         if (li) {
@@ -662,6 +671,7 @@ function submitFiles(allFiles) {
           if (li.removeBtn) li.removeBtn.style.display = "none";
         }
         uploadResults[file.uploadIndex] = true;
+
       } else {
         // real failure
         if (li) {
@@ -681,12 +691,17 @@ function submitFiles(allFiles) {
           }
         }, 5000);
       }
-    
+
       // ─── Only now count this chunk as finished ───────────────────
       finishedCount++;
-      if (finishedCount === allFiles.length) {
-        refreshFileList(allFiles, uploadResults, progressElements);
-      }
+if (finishedCount === allFiles.length) {
+  const succeededCount = uploadResults.filter(Boolean).length;
+  const failedCount = allFiles.length - succeededCount;
+
+  setTimeout(() => {
+    refreshFileList(allFiles, uploadResults, progressElements);
+  }, 250);
+}
     });
 
     xhr.addEventListener("error", function () {
@@ -699,6 +714,9 @@ function submitFiles(allFiles) {
       finishedCount++;
       if (finishedCount === allFiles.length) {
         refreshFileList(allFiles, uploadResults, progressElements);
+        // Immediate summary toast based on actual XHR outcomes
+        const succeededCount = uploadResults.filter(Boolean).length;
+        const failedCount = allFiles.length - succeededCount;
       }
     });
 
@@ -725,17 +743,30 @@ function submitFiles(allFiles) {
     loadFileList(folderToUse)
       .then(serverFiles => {
         initFileActions();
-        serverFiles = (serverFiles || []).map(item => item.name.trim().toLowerCase());
+        // Be tolerant to API shapes: string or object with name/fileName/filename
+        serverFiles = (serverFiles || [])
+          .map(item => {
+            if (typeof item === 'string') return item;
+            const n = item?.name ?? item?.fileName ?? item?.filename ?? '';
+            return String(n);
+          })
+          .map(s => s.trim().toLowerCase())
+          .filter(Boolean);
         let overallSuccess = true;
+        let succeeded = 0;
         allFiles.forEach(file => {
           const clientFileName = file.name.trim().toLowerCase();
           const li = progressElements[file.uploadIndex];
-          if (!uploadResults[file.uploadIndex] || !serverFiles.includes(clientFileName)) {
+          const hadRelative = !!(file.webkitRelativePath || file.customRelativePath);
+          if (!uploadResults[file.uploadIndex] || (!hadRelative && !serverFiles.includes(clientFileName))) {
             if (li) {
               li.progressBar.innerText = "Error";
             }
             overallSuccess = false;
+            
           } else if (li) {
+            succeeded++;
+            
             // Schedule removal of successful file entry after 5 seconds.
             setTimeout(() => {
               li.remove();
@@ -757,9 +788,12 @@ function submitFiles(allFiles) {
             }, 5000);
           }
         });
-        
+
         if (!overallSuccess) {
-          showToast("Some files failed to upload. Please check the list.");
+          const failed = allFiles.length - succeeded;
+          showToast(`${failed} file(s) failed, ${succeeded} succeeded. Please check the list.`);
+        } else {
+          showToast(`${succeeded} file succeeded. Please check the list.`);
         }
       })
       .catch(error => {
@@ -768,6 +802,7 @@ function submitFiles(allFiles) {
       })
       .finally(() => {
         loadFolderTree(window.currentFolder);
+        
       });
   }
 }
diff --git a/src/controllers/FileController.php b/src/controllers/FileController.php
index 49bdaf5..3d2b284 100644
--- a/src/controllers/FileController.php
+++ b/src/controllers/FileController.php
@@ -501,7 +501,7 @@ public function deleteFiles()
             $userPermissions = $this->loadPerms($username);
     
             // Need granular rename (or ancestor-owner)
-            if (!(ACL::canRename($username, $userPermissions, $folder) || $this->ownsFolderOrAncestor($folder, $username, $userPermissions))) {
+            if (!(ACL::canRename($username, $userPermissions, $folder))) {
                 $this->_jsonOut(["error"=>"Forbidden: no rename rights"], 403); return;
             }
     
diff --git a/src/controllers/FolderController.php b/src/controllers/FolderController.php
index 6624322..e6ae309 100644
--- a/src/controllers/FolderController.php
+++ b/src/controllers/FolderController.php
@@ -695,4 +695,79 @@ for ($i = $startPage; $i <= $endPage; $i++): ?>
             echo json_encode(['success' => false, 'error' => 'Not found']);
         }
     }
-}
\ No newline at end of file
+
+    /* -------------------- API: Move Folder -------------------- */
+    public function moveFolder(): void
+    {
+        header('Content-Type: application/json; charset=utf-8');
+        self::requireAuth();
+        if (($_SERVER['REQUEST_METHOD'] ?? 'GET') !== 'POST') { http_response_code(405); echo json_encode(['error'=>'Method not allowed']); return; }
+        // CSRF: accept header or form field
+        $hdr = $_SERVER['HTTP_X_CSRF_TOKEN'] ?? '';
+        $tok = $_SESSION['csrf_token'] ?? '';
+        if (!$hdr || !$tok || !hash_equals((string)$tok, (string)$hdr)) { http_response_code(403); echo json_encode(['error'=>'Invalid CSRF token']); return; }
+
+        $raw = file_get_contents('php://input');
+        $input = json_decode($raw ?: "{}", true);
+        $source = trim((string)($input['source'] ?? ''));
+        $destination = trim((string)($input['destination'] ?? ''));
+
+        if ($source === '' || strcasecmp($source,'root')===0) { http_response_code(400); echo json_encode(['error'=>'Invalid source folder']); return; }
+        if ($destination === '') $destination = 'root';
+
+        // basic segment validation
+        foreach ([$source,$destination] as $f) {
+            if ($f==='root') continue;
+            $parts = array_filter(explode('/', trim($f, "/\\ ")), fn($p)=>$p!=='');
+            foreach ($parts as $seg) {
+                if (!preg_match(REGEX_FOLDER_NAME, $seg)) { http_response_code(400); echo json_encode(['error'=>'Invalid folder segment']); return; }
+            }
+        }
+
+        $srcNorm = trim($source, "/\\ ");
+        $dstNorm = $destination==='root' ? '' : trim($destination, "/\\ ");
+
+        // prevent move into self/descendant
+        if ($dstNorm !== '' && (strcasecmp($dstNorm,$srcNorm)===0 || strpos($dstNorm.'/', $srcNorm.'/')===0)) {
+            http_response_code(400); echo json_encode(['error'=>'Destination cannot be the source or its descendant']); return;
+        }
+
+        $username = $_SESSION['username'] ?? '';
+        $perms = $this->loadPerms($username);
+
+        // enforce scopes (source manage-ish, dest write-ish)
+        if ($msg = self::enforceFolderScope($source, $username, $perms, 'manage')) { http_response_code(403); echo json_encode(['error'=>$msg]); return; }
+        if ($msg = self::enforceFolderScope($destination, $username, $perms, 'write')) { http_response_code(403); echo json_encode(['error'=>$msg]); return; }
+
+        // Check capabilities using ACL helpers
+        $canManageSource = ACL::canManage($username, $perms, $source) || ACL::isOwner($username, $perms, $source);
+        $canMoveIntoDest = ACL::canMove($username, $perms, $destination) || ($destination==='root' ? self::isAdmin($perms) : ACL::isOwner($username, $perms, $destination));
+        if (!$canManageSource) { http_response_code(403); echo json_encode(['error'=>'Forbidden: manage rights required on source']); return; }
+        if (!$canMoveIntoDest) { http_response_code(403); echo json_encode(['error'=>'Forbidden: move rights required on destination']); return; }
+
+        // Non-admin: enforce same owner between source and destination tree (if any)
+        $isAdmin = self::isAdmin($perms);
+        if (!$isAdmin) {
+            try {
+                $ownerSrc = FolderModel::getOwnerFor($source) ?? '';
+                $ownerDst = $destination==='root' ? '' : (FolderModel::getOwnerFor($destination) ?? '');
+                if ($ownerSrc !== $ownerDst) {
+                    http_response_code(403); echo json_encode(['error'=>'Source and destination must have the same owner']); return;
+                }
+            } catch (\Throwable $e) { /* ignore – fall through */ }
+        }
+
+        // Compute final target "destination/basename(source)"
+        $baseName = basename(str_replace('\\','/', $srcNorm));
+        $target   = $destination==='root' ? $baseName : rtrim($destination, "/\\ ") . '/' . $baseName;
+
+        try {
+            $result = FolderModel::renameFolder($source, $target);
+            echo json_encode($result, JSON_UNESCAPED_UNICODE | JSON_UNESCAPED_SLASHES);
+        } catch (\Throwable $e) {
+            error_log('moveFolder error: '.$e->getMessage());
+            http_response_code(500);
+            echo json_encode(['error'=>'Internal error moving folder']);
+        }
+    }
+}
diff --git a/src/lib/ACL.php b/src/lib/ACL.php
index 0100756..f9032da 100644
--- a/src/lib/ACL.php
+++ b/src/lib/ACL.php
@@ -40,6 +40,48 @@ class ACL
         unset($rec);
         return $changed ? self::save($acl) : true;
     }
+    public static function ownsFolderOrAncestor(string $user, array $perms, string $folder): bool
+{
+    $folder = self::normalizeFolder($folder);
+    if (self::isAdmin($perms)) return true;
+    if (self::hasGrant($user, $folder, 'owners')) return true;
+
+    $folder = trim($folder, "/\\ ");
+    if ($folder === '' || $folder === 'root') return false;
+
+    $parts = explode('/', $folder);
+    while (count($parts) > 1) {
+        array_pop($parts);
+        $parent = implode('/', $parts);
+        if (self::hasGrant($user, $parent, 'owners')) return true;
+    }
+    return false;
+}
+
+    /** Re-key explicit ACL entries for an entire subtree: old/... → new/... */
+public static function renameTree(string $oldFolder, string $newFolder): void
+{
+    $old = self::normalizeFolder($oldFolder);
+    $new = self::normalizeFolder($newFolder);
+    if ($old === '' || $old === 'root') return; // nothing to re-key for root
+
+    $acl = self::$cache ?? self::loadFresh();
+    if (!isset($acl['folders']) || !is_array($acl['folders'])) return;
+
+    $rebased = [];
+    foreach ($acl['folders'] as $k => $rec) {
+        if ($k === $old || strpos($k, $old . '/') === 0) {
+            $suffix = substr($k, strlen($old));
+            $suffix = ltrim((string)$suffix, '/');
+            $newKey = $new . ($suffix !== '' ? '/' . $suffix : '');
+            $rebased[$newKey] = $rec;
+        } else {
+            $rebased[$k] = $rec;
+        }
+    }
+    $acl['folders'] = $rebased;
+    self::save($acl);
+}
 
     private static function loadFresh(): array {
         $path = self::path();
@@ -323,10 +365,10 @@ class ACL
                 $sf  = !empty($caps['shareFile'])   || !empty($caps['share_file']);
                 $sfo = !empty($caps['shareFolder']) || !empty($caps['share_folder']);
 
-                if ($m) { $v = true; $w = true; $u = $c = $ed = $rn = $cp = $mv = $dl = $ex = $sf = $sfo = true; }
+                if ($m) { $v = true; $w = true; $u = $c = $ed = $rn = $cp = $dl = $ex = $sf = $sfo = true; }
                 if ($u && !$v && !$vo) $vo = true;
                 //if ($s && !$v) $v = true;
-                if ($w) { $c = $u = $ed = $rn = $cp = $mv = $dl = $ex = true; }
+                if ($w) { $c = $u = $ed = $rn = $cp = $dl = $ex = true; }
 
                 if ($m)  $rec['owners'][]       = $user;
                 if ($v)  $rec['read'][]         = $user;
@@ -419,9 +461,13 @@ public static function canCopy(string $user, array $perms, string $folder): bool
 public static function canMove(string $user, array $perms, string $folder): bool {
     $folder = self::normalizeFolder($folder);
     if (self::isAdmin($perms)) return true;
-    return self::hasGrant($user, $folder, 'owners')
-        || self::hasGrant($user, $folder, 'move')
-        || self::hasGrant($user, $folder, 'write');
+    return self::ownsFolderOrAncestor($user, $perms, $folder);
+}
+
+public static function canMoveFolder(string $user, array $perms, string $folder): bool {
+    $folder = self::normalizeFolder($folder);
+    if (self::isAdmin($perms)) return true;
+    return self::ownsFolderOrAncestor($user, $perms, $folder);
 }
 
 public static function canDelete(string $user, array $perms, string $folder): bool {
diff --git a/src/models/FolderModel.php b/src/models/FolderModel.php
index 386a8b3..7b05820 100644
--- a/src/models/FolderModel.php
+++ b/src/models/FolderModel.php
@@ -326,6 +326,8 @@ class FolderModel
 
         // Update ownership mapping for the entire subtree.
         self::renameOwnersForTree($oldRel, $newRel);
+        // Re-key explicit ACLs for the moved subtree
+        ACL::renameTree($oldRel, $newRel);
 
         return ["success" => true];
     }
diff --git a/src/models/UploadModel.php b/src/models/UploadModel.php
index 358ea70..5f99907 100644
--- a/src/models/UploadModel.php
+++ b/src/models/UploadModel.php
@@ -4,6 +4,19 @@
 require_once PROJECT_ROOT . '/config/config.php';
 
 class UploadModel {
+
+    private static function sanitizeFolder(string $folder): string {
+                $folder = trim($folder);
+                if ($folder === '' || strtolower($folder) === 'root') return '';
+                // no traversal
+                if (strpos($folder, '..') !== false) return '';
+                // only safe chars + forward slashes
+                if (!preg_match('/^[A-Za-z0-9_\-\/]+$/', $folder)) return '';
+                // normalize: strip leading slashes
+                return ltrim($folder, '/');
+            }
+
+
     /**
      * Handles file uploads – supports both chunked uploads and full (non-chunked) uploads.
      *
@@ -38,15 +51,19 @@ class UploadModel {
                 return ["error" => "Invalid file name: $resumableFilename"];
             }
             
-            $folder = isset($post['folder']) ? trim($post['folder']) : 'root';
-            if ($folder !== 'root' && !preg_match(REGEX_FOLDER_NAME, $folder)) {
-                return ["error" => "Invalid folder name"];
-            }
+            $folderRaw = $post['folder'] ?? 'root';
+            $folderSan = self::sanitizeFolder((string)$folderRaw);
+
+            
+            if (empty($files['file']) || !isset($files['file']['name'])) {
+                        return ["error" => "No files received"];
+                    }
             
             $baseUploadDir = UPLOAD_DIR;
-            if ($folder !== 'root') {
-                $baseUploadDir = rtrim(UPLOAD_DIR, '/\\') . DIRECTORY_SEPARATOR . $folder . DIRECTORY_SEPARATOR;
-            }
+            if ($folderSan !== '') {
+                                $baseUploadDir = rtrim(UPLOAD_DIR, '/\\') . DIRECTORY_SEPARATOR
+                                               . str_replace('/', DIRECTORY_SEPARATOR, $folderSan) . DIRECTORY_SEPARATOR;
+                            }
             if (!is_dir($baseUploadDir) && !mkdir($baseUploadDir, 0775, true)) {
                 return ["error" => "Failed to create upload directory"];
             }
@@ -56,12 +73,14 @@ class UploadModel {
                 return ["error" => "Failed to create temporary chunk directory"];
             }
             
-            if (!isset($files["file"]) || $files["file"]["error"] !== UPLOAD_ERR_OK) {
+            $chunkErr = $files['file']['error'] ?? UPLOAD_ERR_NO_FILE;
+            if ($chunkErr !== UPLOAD_ERR_OK) {
                 return ["error" => "Upload error on chunk $chunkNumber"];
             }
             
             $chunkFile = $tempDir . $chunkNumber;
-            if (!move_uploaded_file($files["file"]["tmp_name"], $chunkFile)) {
+            $tmpName = $files['file']['tmp_name'] ?? null;
+            if (!$tmpName || !move_uploaded_file($tmpName, $chunkFile)) {
                 return ["error" => "Failed to move uploaded chunk $chunkNumber"];
             }
             
@@ -100,8 +119,7 @@ class UploadModel {
             fclose($out);
             
             // Update metadata.
-            $relativeFolder = $folder;
-            $metadataKey = ($relativeFolder === '' || strtolower($relativeFolder) === 'root') ? "root" : $relativeFolder;
+            $metadataKey = ($folderSan === '') ? "root" : $folderSan;
             $metadataFileName = str_replace(['/', '\\', ' '], '-', $metadataKey) . '_metadata.json';
             $metadataFile = META_DIR . $metadataFileName;
             $uploadedDate = date(DATE_TIME_FORMAT);
@@ -134,16 +152,16 @@ class UploadModel {
             
             return ["success" => "File uploaded successfully"];
         } else {
-            // Handle full upload (non-chunked).
-            $folder = isset($post['folder']) ? trim($post['folder']) : 'root';
-            if ($folder !== 'root' && !preg_match(REGEX_FOLDER_NAME, $folder)) {
-                return ["error" => "Invalid folder name"];
+                        // Handle full upload (non-chunked)
+                        $folderRaw = $post['folder'] ?? 'root';
+                        $folderSan = self::sanitizeFolder((string)$folderRaw);
             }
             
             $baseUploadDir = UPLOAD_DIR;
-            if ($folder !== 'root') {
-                $baseUploadDir = rtrim(UPLOAD_DIR, '/\\') . DIRECTORY_SEPARATOR . $folder . DIRECTORY_SEPARATOR;
-            }
+            if ($folderSan !== '') {
+                                $baseUploadDir = rtrim(UPLOAD_DIR, '/\\') . DIRECTORY_SEPARATOR
+                                               . str_replace('/', DIRECTORY_SEPARATOR, $folderSan) . DIRECTORY_SEPARATOR;
+                            }
             if (!is_dir($baseUploadDir) && !mkdir($baseUploadDir, 0775, true)) {
                 return ["error" => "Failed to create upload directory"];
             }
@@ -153,6 +171,10 @@ class UploadModel {
             $metadataChanged = [];
             
             foreach ($files["file"]["name"] as $index => $fileName) {
+                // Basic PHP upload error check per file
+                if (($files['file']['error'][$index] ?? UPLOAD_ERR_OK) !== UPLOAD_ERR_OK) {
+                        return ["error" => "Error uploading file"];
+                    }
                 $safeFileName = trim(urldecode(basename($fileName)));
                 if (!preg_match($safeFileNamePattern, $safeFileName)) {
                     return ["error" => "Invalid file name: " . $fileName];
@@ -161,21 +183,22 @@ class UploadModel {
                 if (isset($post['relativePath'])) {
                     $relativePath = is_array($post['relativePath']) ? $post['relativePath'][$index] ?? '' : $post['relativePath'];
                 }
-                $uploadDir = $baseUploadDir;
+                $uploadDir = rtrim($baseUploadDir, '/\\') . DIRECTORY_SEPARATOR;
                 if (!empty($relativePath)) {
                     $subDir = dirname($relativePath);
                     if ($subDir !== '.' && $subDir !== '') {
-                        $uploadDir = rtrim(UPLOAD_DIR, '/\\') . DIRECTORY_SEPARATOR . str_replace('/', DIRECTORY_SEPARATOR, $subDir) . DIRECTORY_SEPARATOR;
+                      // IMPORTANT: build the subfolder under the *current* base folder
+                        $uploadDir = rtrim($baseUploadDir, '/\\') . DIRECTORY_SEPARATOR .
+                                     str_replace('/', DIRECTORY_SEPARATOR, $subDir) . DIRECTORY_SEPARATOR;
                     }
                     $safeFileName = basename($relativePath);
                 }
-                if (!is_dir($uploadDir) && !mkdir($uploadDir, 0775, true)) {
-                    return ["error" => "Failed to create subfolder"];
+                if (!is_dir($uploadDir) && !@mkdir($uploadDir, 0775, true)) {
+                    return ["error" => "Failed to create subfolder: " . $uploadDir];
                 }
                 $targetPath = $uploadDir . $safeFileName;
                 if (move_uploaded_file($files["file"]["tmp_name"][$index], $targetPath)) {
-                    $folderPath = $folder;
-                    $metadataKey = ($folderPath === '' || strtolower($folderPath) === 'root') ? "root" : $folderPath;
+                                        $metadataKey = ($folderSan === '') ? "root" : $folderSan;
                     $metadataFileName = str_replace(['/', '\\', ' '], '-', $metadataKey) . '_metadata.json';
                     $metadataFile = META_DIR . $metadataFileName;
                     if (!isset($metadataCollection[$metadataKey])) {
@@ -208,7 +231,7 @@ class UploadModel {
             }
             return ["success" => "Files uploaded successfully"];
         }
-    }
+    
 
         /**
      * Recursively removes a directory and its contents.