diff --git a/frontend/src/DesktopWorkspace.jsx b/frontend/src/DesktopWorkspace.jsx
index 776bcf6..0ad4b2f 100644
--- a/frontend/src/DesktopWorkspace.jsx
+++ b/frontend/src/DesktopWorkspace.jsx
@@ -581,6 +581,8 @@ const DesktopWorkspace = ({
   activeTagIds = [],
   selectedDocumentIds = [],
   onClearSelection = null,
+  detailPanelOpen = false,
+  onCloseDetailPanel = null,
   helpOpen = false,
   onHelpClose = null,
   tenantId = null,
@@ -1849,6 +1851,8 @@ const recalcVisibleDocIds = useCallback(() => {
       markLayoutDirty,
       selectedDocumentIds,
       onClearSelection,
+      detailPanelOpen,
+      onCloseDetailPanel,
     }),
     [
       activeTagSet,
@@ -1897,6 +1901,8 @@ const recalcVisibleDocIds = useCallback(() => {
       onClearSelection,
       onDocumentStackSelect,
       markLayoutDirty,
+      detailPanelOpen,
+      onCloseDetailPanel,
     ],
   );
 
@@ -1945,6 +1951,8 @@ const DesktopWorkspaceView = () => {
     onDocumentStackSelect,
     selectedDocumentIds,
     onClearSelection,
+    detailPanelOpen,
+    onCloseDetailPanel,
     documentLookup,
   } = useDesktopContext();
 
@@ -2151,11 +2159,8 @@ const DesktopWorkspaceView = () => {
       }
 
       const key = event.key;
-      if (!(key === ' ' || key === 'Space' || key === 'Spacebar')) {
-        return;
-      }
-
-      if (!selectedDocumentIds || selectedDocumentIds.length === 0) {
+      const spacePressed = key === ' ' || key === 'Space' || key === 'Spacebar';
+      if (!spacePressed) {
         return;
       }
 
@@ -2173,13 +2178,27 @@ const DesktopWorkspaceView = () => {
         }
       }
 
-      event.preventDefault();
-      onClearSelection();
+      const hasSelection = Array.isArray(selectedDocumentIds) && selectedDocumentIds.length > 0;
+      if (hasSelection) {
+        event.preventDefault();
+        onClearSelection();
+        return;
+      }
+
+      if (detailPanelOpen && typeof onCloseDetailPanel === 'function') {
+        event.preventDefault();
+        onCloseDetailPanel();
+      }
     };
 
     window.addEventListener('keydown', handleKeyDown, true);
     return () => window.removeEventListener('keydown', handleKeyDown, true);
-  }, [onClearSelection, selectedDocumentIds]);
+  }, [
+    onClearSelection,
+    selectedDocumentIds,
+    detailPanelOpen,
+    onCloseDetailPanel,
+  ]);
 
   return (
     <>
@@ -2284,32 +2303,39 @@ const DesktopWorkspaceView = () => {
                       (event.metaKey || event.ctrlKey) && !event.shiftKey && !event.altKey;
 
                     let stackDocIds = null;
-                    if (
-                      metaOrCtrlOnly
-                      && selectedDocumentIds.length === 0
-                      && typeof onDocumentStackSelect === 'function'
-                    ) {
+                    let appliedStackSelection = false;
+
+                    if (metaOrCtrlOnly) {
                       const hits = resolveStackDocIds(event, doc.id);
                       if (Array.isArray(hits) && hits.length > 0) {
                         stackDocIds = hits;
-                        onDocumentStackSelect(hits, event);
+                        const hasStack = hits.length > 1;
+                        if (hasStack && alreadySelected && typeof onDocumentStackSelect === 'function') {
+                          onDocumentStackSelect(hits, event);
+                          appliedStackSelection = true;
+                        }
                       }
                     }
 
-                    const stackHandled = Array.isArray(stackDocIds) && stackDocIds.length > 0;
-
-                    if (
-                      !stackHandled
-                      && typeof onDocumentPointerSelect === 'function'
-                      && (!alreadySelected
-                        || event.metaKey
-                        || event.ctrlKey
+                    const shouldInvokePointerSelect =
+                      typeof onDocumentPointerSelect === 'function'
+                      && (
+                        !metaOrCtrlOnly
+                        || !alreadySelected
                         || event.shiftKey
-                        || event.altKey)
-                    ) {
+                        || event.altKey
+                        || !stackDocIds
+                        || stackDocIds.length <= 1
+                      );
+
+                    if (shouldInvokePointerSelect) {
                       onDocumentPointerSelect(doc.id, event);
                     }
-                    handlePointerDown(event, doc.id, { stackDocIds });
+
+                    handlePointerDown(event, doc.id, {
+                      stackDocIds,
+                      stackSelectionApplied: appliedStackSelection,
+                    });
                   }}
                   onPointerMove={handlePointerMove}
                   onPointerUp={handlePointerUp}
diff --git a/frontend/src/app/AppLayout.jsx b/frontend/src/app/AppLayout.jsx
index 01cf362..a571aa2 100644
--- a/frontend/src/app/AppLayout.jsx
+++ b/frontend/src/app/AppLayout.jsx
@@ -4885,6 +4885,8 @@ const AppLayout = () => {
       tenantId: currentTenantId,
       selectedDocumentIds,
       onClearSelection: clearDocumentSelection,
+      detailPanelOpen,
+      onCloseDetailPanel: handleDetailPanelClose,
       resolveThumbnailUrl: resolveThumbnailUrlForDoc,
       onAssignTagToDocument: handleDocumentTagAttach,
       onRemoveTagFromDocument: handleTagRemove,
@@ -4911,6 +4913,8 @@ const AppLayout = () => {
       deskHelpOpen,
       selectedDocumentIds,
       clearDocumentSelection,
+      detailPanelOpen,
+      handleDetailPanelClose,
       resolveThumbnailUrlForDoc,
       handleDocumentTagAttach,
       handleTagRemove,
diff --git a/frontend/src/desktop/useDocumentDrag.js b/frontend/src/desktop/useDocumentDrag.js
index a2d6369..2c2b18f 100644
--- a/frontend/src/desktop/useDocumentDrag.js
+++ b/frontend/src/desktop/useDocumentDrag.js
@@ -32,6 +32,7 @@ const useDocumentDrag = () => {
     containerRef,
     onDocumentOpen,
     onInspectDocument,
+    onDocumentStackSelect,
     selectedDocumentIds,
     markLayoutDirty,
   } = useDesktopContext();
@@ -286,6 +287,7 @@ const useDocumentDrag = () => {
             .map((value) => (value != null ? String(value) : null))
             .filter(Boolean)
         : null;
+      const stackSelectionAppliedInitial = Boolean(options?.stackSelectionApplied);
 
       let selectionIds = Array.isArray(selectedDocumentIds)
         ? selectedDocumentIds.map((id) => String(id))
@@ -416,6 +418,8 @@ const useDocumentDrag = () => {
             ? performance.now()
             : Date.now();
 
+      const hasStackSource = Array.isArray(stackDocIdsOption) && stackDocIdsOption.length > 1;
+
       dragStateRef.current = {
         docId,
         docKey,
@@ -444,9 +448,11 @@ const useDocumentDrag = () => {
         containerRectTop: containerTop,
         isGroup: isGroupDrag,
         groupDocIds,
-      groupItems,
-      groupElevated: !isGroupDrag,
-    };
+        groupItems,
+        groupElevated: !isGroupDrag,
+        stackDocIds: hasStackSource ? stackDocIdsOption : null,
+        stackSelectionApplied: stackSelectionAppliedInitial || !hasStackSource,
+      };
 
     setDraggingId(docId);
 
@@ -524,6 +530,17 @@ const useDocumentDrag = () => {
           return;
         }
         state.moved = true;
+        if (
+          state.isGroup
+          && !state.stackSelectionApplied
+          && Array.isArray(state.stackDocIds)
+          && state.stackDocIds.length > 1
+        ) {
+          if (typeof onDocumentStackSelect === 'function') {
+            onDocumentStackSelect(state.stackDocIds);
+          }
+          state.stackSelectionApplied = true;
+        }
         if (!state.groupElevated) {
           const layout = layoutRef.current;
           const sortedGroup = state.groupDocIds
@@ -811,6 +828,7 @@ const useDocumentDrag = () => {
       applyTransform,
       recalcVisibleDocIds,
       debugDrag,
+      onDocumentStackSelect,
     ],
   );
 
diff --git a/frontend/src/detail/PreviewZoomOverlay.jsx b/frontend/src/detail/PreviewZoomOverlay.jsx
index 4388437..e48c0d6 100644
--- a/frontend/src/detail/PreviewZoomOverlay.jsx
+++ b/frontend/src/detail/PreviewZoomOverlay.jsx
@@ -173,13 +173,33 @@ const PreviewZoomOverlay = ({
       return;
     }
 
-    if (event.key === 'Escape') {
+    const key = event.key;
+
+    if (key === ' ' || key === 'Space' || key === 'Spacebar') {
+      const target = event.target;
+      if (target instanceof HTMLElement) {
+        const tag = target.tagName ? target.tagName.toLowerCase() : '';
+        if (
+          target.isContentEditable
+          || tag === 'input'
+          || tag === 'textarea'
+          || tag === 'select'
+        ) {
+          return;
+        }
+      }
       event.preventDefault();
       onClose();
       return;
     }
 
-    if (event.key === 'ArrowLeft') {
+    if (key === 'Escape') {
+      event.preventDefault();
+      onClose();
+      return;
+    }
+
+    if (key === 'ArrowLeft') {
       if (activeDisplay?.canGoPrev && activeDisplay?.goPrev) {
         event.preventDefault();
         activeDisplay.goPrev();
@@ -187,7 +207,7 @@ const PreviewZoomOverlay = ({
       return;
     }
 
-    if (event.key === 'ArrowRight') {
+    if (key === 'ArrowRight') {
       if (activeDisplay?.canGoNext && activeDisplay?.goNext) {
         event.preventDefault();
         activeDisplay.goNext();