diff --git a/imagemodel.cpp b/imagemodel.cpp
index 5c58083..3288ae0 100644
--- a/imagemodel.cpp
+++ b/imagemodel.cpp
@@ -4,6 +4,7 @@
 #include <QDir>
 #include <QImageReader>
 #include <QFileInfo>
+#include <QFileIconProvider>
 
 ImageModel::ImageModel(QObject *parent)
     : QAbstractListModel(parent)
@@ -12,6 +13,9 @@ ImageModel::ImageModel(QObject *parent)
 
     m_placeholder = QPixmap(128, 128);
     m_placeholder.fill(Qt::lightGray);
+
+    QFileIconProvider iconProvider;
+    m_folderIcon = iconProvider.icon(QFileIconProvider::Folder);
 }
 
 ImageModel::~ImageModel()
@@ -29,8 +33,22 @@ void ImageModel::setDirectory(const QString &path)
     beginResetModel();
     m_items.clear();
     m_pendingRows.clear();
+    m_currentDir = path;
 
     QDir dir(path);
+
+    // Add subdirectories first
+    dir.setFilter(QDir::AllDirs | QDir::NoDot);
+    dir.setSorting(QDir::Name);
+    const auto dirs = dir.entryInfoList();
+    QPixmap folderPixmap = m_folderIcon.pixmap(128, 128);
+    for (const QFileInfo &d : dirs)
+    {
+        QString name = d.fileName();  // preserves ".." for the parent entry
+        m_items.append({d.absoluteFilePath(), name, folderPixmap, true, true});
+    }
+
+    // Then add image files
     QStringList filters;
 
     const auto formats = QImageReader::supportedImageFormats();
@@ -39,12 +57,13 @@ void ImageModel::setDirectory(const QString &path)
 
     dir.setNameFilters(filters);
     dir.setFilter(QDir::Files);
+    dir.setSorting(QDir::Name);
 
     const auto files = dir.entryInfoList();
 
     for (const QFileInfo &file : files)
     {
-        m_items.append({file.absoluteFilePath(), m_placeholder, false});
+        m_items.append({file.absoluteFilePath(), file.fileName(), m_placeholder, false, false});
     }
 
     endResetModel();
@@ -60,18 +79,18 @@ void ImageModel::requestThumbnails(int firstRow, int lastRow)
 
     for (int row = firstRow; row <= lastRow; ++row)
     {
-        if (!m_items[row].loaded)
+        if (!m_items[row].loaded && !m_items[row].isFolder)
             queueRow(row);
     }
 
     // Optional: preload nearby rows
     int buffer = 20;
     for (int row = firstRow - buffer; row < firstRow; ++row)
-        if (row >= 0 && !m_items[row].loaded)
+        if (row >= 0 && !m_items[row].loaded && !m_items[row].isFolder)
             queueRow(row);
 
     for (int row = lastRow + 1; row <= lastRow + buffer; ++row)
-        if (row < m_items.size() && !m_items[row].loaded)
+        if (row < m_items.size() && !m_items[row].loaded && !m_items[row].isFolder)
             queueRow(row);
 }
 
@@ -102,6 +121,18 @@ QString ImageModel::filePath(const QModelIndex &index) const
     return m_items[index.row()].path;
 }
 
+bool ImageModel::isFolder(const QModelIndex &index) const
+{
+    if (!index.isValid() || index.row() >= m_items.size())
+        return false;
+    return m_items[index.row()].isFolder;
+}
+
+QString ImageModel::currentDirectory() const
+{
+    return m_currentDir;
+}
+
 int ImageModel::rowCount(const QModelIndex &) const
 {
     return m_items.size();
@@ -118,7 +149,7 @@ QVariant ImageModel::data(const QModelIndex &index, int role) const
         return item.thumbnail;
 
     if (role == Qt::DisplayRole)
-        return QFileInfo(item.path).fileName();
+        return item.displayName;
 
     return {};
 }
diff --git a/imagemodel.h b/imagemodel.h
index c124ae6..7586159 100644
--- a/imagemodel.h
+++ b/imagemodel.h
@@ -6,6 +6,7 @@
 #include <QThreadPool>
 #include <QSet>
 #include <atomic>
+#include <QIcon>
 
 class ThumbnailWorker;
 
@@ -19,6 +20,8 @@ public:
 
     void setDirectory(const QString &path);
     QString filePath(const QModelIndex &index) const;
+    bool isFolder(const QModelIndex &index) const;
+    QString currentDirectory() const;
 
     void requestThumbnails(int firstRow, int lastRow);
 
@@ -31,8 +34,10 @@ private:
     struct Item
     {
         QString path;
+        QString displayName;
         QPixmap thumbnail;
         bool loaded = false;
+        bool isFolder = false;
     };
 
     void queueRow(int row);
@@ -43,4 +48,6 @@ private:
 
     QSet<int> m_pendingRows;
     std::atomic_bool m_cancelFlag{false};
+    QIcon m_folderIcon;
+    QString m_currentDir;
 };
diff --git a/mainwindow.cpp b/mainwindow.cpp
index 0dc9252..aa686c6 100644
--- a/mainwindow.cpp
+++ b/mainwindow.cpp
@@ -125,7 +125,19 @@ void MainWindow::setupConnections()
             this, [this](const QModelIndex &current) { showPreview(current); });
 
     connect(m_listView, &QListView::doubleClicked, this,
-            [this](const QModelIndex &index) { enterSingleImageMode(index); });
+            [this](const QModelIndex &index) {
+                if (m_imageModel->isFolder(index)) {
+                    QString path = m_imageModel->filePath(index);
+                    m_imageModel->setDirectory(path);
+                    // Update tree view selection to match
+                    QModelIndex dirIdx = m_dirModel->index(path);
+                    if (dirIdx.isValid())
+                        m_treeView->setCurrentIndex(dirIdx);
+                    QTimer::singleShot(0, this, &MainWindow::loadVisibleThumbnails);
+                } else {
+                    enterSingleImageMode(index);
+                }
+            });
 
     connect(m_imageView, &ImageViewWidget::closeRequested,
             this, &MainWindow::leaveSingleImageMode);
@@ -133,6 +145,8 @@ void MainWindow::setupConnections()
     connect(m_imageView, &ImageViewWidget::nextRequested, this, [this]() {
         QModelIndex cur = m_listView->currentIndex();
         int next = cur.isValid() ? cur.row() + 1 : 0;
+        while (next < m_imageModel->rowCount() && m_imageModel->isFolder(m_imageModel->index(next)))
+            ++next;
         if (next < m_imageModel->rowCount())
         {
             QModelIndex idx = m_imageModel->index(next);
@@ -144,6 +158,8 @@ void MainWindow::setupConnections()
     connect(m_imageView, &ImageViewWidget::previousRequested, this, [this]() {
         QModelIndex cur = m_listView->currentIndex();
         int prev = cur.isValid() ? cur.row() - 1 : 0;
+        while (prev >= 0 && m_imageModel->isFolder(m_imageModel->index(prev)))
+            --prev;
         if (prev >= 0)
         {
             QModelIndex idx = m_imageModel->index(prev);
@@ -245,7 +261,16 @@ void MainWindow::keyPressEvent(QKeyEvent *event)
         QModelIndex current = m_listView->currentIndex();
         if (current.isValid())
         {
-            enterSingleImageMode(current);
+            if (m_imageModel->isFolder(current)) {
+                QString path = m_imageModel->filePath(current);
+                m_imageModel->setDirectory(path);
+                QModelIndex dirIdx = m_dirModel->index(path);
+                if (dirIdx.isValid())
+                    m_treeView->setCurrentIndex(dirIdx);
+                QTimer::singleShot(0, this, &MainWindow::loadVisibleThumbnails);
+            } else {
+                enterSingleImageMode(current);
+            }
             event->accept();
             return;
         }