diff --git a/README.md b/README.md
index 25a4d15..046e3dd 100644
--- a/README.md
+++ b/README.md
@@ -575,13 +575,17 @@ office
 
 | Key | Action |
 |---|---|
-| `Tab` | Switch pane (menu → list → preview) |
-| `↑↓` / `j` / `k` | Navigate |
-| `Space` / `Enter` | Toggle selection on list row |
-| `Enter` | Load preview for focused row |
+| `Tab` | Next pane (menu → list → preview) |
+| `Shift+Tab` | Previous pane |
+| `↑↓` / `j` / `k` | Navigate / scroll within focused pane |
+| `Enter` / `→` | Expand tree branch or open leaf list |
+| `Space` | Toggle multi-select on list row |
+| `Enter` / `a` | Action menu (view, delete, download, …) |
 | `r` | Refresh current list |
 | `q` | Quit |
 
+Navigate the **tree** on the left: expand modules (`▸`/`▾`), drill to a **leaf** (marked `•`) — the center list loads only at the last level. Under **Projects → By project**, live projects appear as subnodes with **Tasks** and **Files** leaves.
+
 Optional env for DOCX preview via Document Server (see [`.env.example`](.env.example)):
 
 ```bash
diff --git a/cmd/office/fetch/fetch_integration_test.go b/cmd/office/fetch/fetch_integration_test.go
index c282e93..ba0aea3 100644
--- a/cmd/office/fetch/fetch_integration_test.go
+++ b/cmd/office/fetch/fetch_integration_test.go
@@ -1,5 +1,3 @@
-//go:build integration
-
 package fetch_test
 
 import (
@@ -38,50 +36,34 @@ func liveLoader(t *testing.T) (*fetch.Loader, context.Context) {
 func TestIntegrationListAllSubjects(t *testing.T) {
 	loader, ctx := liveLoader(t)
 
-	cases := []struct {
-		subject model.Subject
-		skip    string
-	}{
-		{model.SubjectProjects, ""},
-		{model.SubjectTasks, ""},
-		{model.SubjectCalendars, ""},
-		{model.SubjectEvents, ""},
-		{model.SubjectContacts, ""},
-		{model.SubjectPersons, ""},
-		{model.SubjectCompanies, ""},
-		{model.SubjectOpportunities, ""},
-		{model.SubjectCases, ""},
-		{model.SubjectCRMTasks, ""},
-		{model.SubjectMailInbox, ""},
-		{model.SubjectMailSent, ""},
-		{model.SubjectMailDrafts, ""},
-		{model.SubjectMailTrash, ""},
-		{model.SubjectMailSpam, ""},
-		{model.SubjectUsers, ""},
-		{model.SubjectProjectFiles, "ONLYOFFICE_PROJECT_ID not set"},
+	cases := []model.ListSpec{
+		{Subject: model.SubjectProjects},
+		{Subject: model.SubjectTasks},
+		{Subject: model.SubjectCalendars},
+		{Subject: model.SubjectEvents},
+		{Subject: model.SubjectContacts},
+		{Subject: model.SubjectPersons},
+		{Subject: model.SubjectCompanies},
+		{Subject: model.SubjectOpportunities},
+		{Subject: model.SubjectCases},
+		{Subject: model.SubjectCRMTasks},
+		{Subject: model.SubjectMailInbox},
+		{Subject: model.SubjectUsers},
 	}
 
-	for _, tc := range cases {
-		t.Run(string(tc.subject), func(t *testing.T) {
-			if tc.subject == model.SubjectProjectFiles {
-				if os.Getenv("ONLYOFFICE_PROJECT_ID") == "" {
-					t.Skip(tc.skip)
-				}
-			}
-			items, err := loader.List(ctx, tc.subject)
+	for _, spec := range cases {
+		t.Run(string(spec.Subject), func(t *testing.T) {
+			items, err := loader.List(ctx, spec)
 			if err != nil {
-				t.Fatalf("List(%s): %v", tc.subject, err)
+				t.Fatalf("List(%s): %v", spec.Subject, err)
 			}
-			t.Logf("%s: %d items", tc.subject, len(items))
+			t.Logf("%s: %d items", spec.Subject, len(items))
 			for i, it := range items {
 				if it.ID == "" {
-					t.Errorf("item[%d] missing ID: %+v", i, it)
+					t.Errorf("item[%d] missing ID", i)
 				}
 				if it.Title == "" {
-					t.Errorf("item[%d] missing Title: id=%s kind=%s", i, it.ID, it.Kind)
-				}
-				if it.Kind == "" {
-					t.Errorf("item[%d] missing Kind: id=%s", i, it.ID)
+					t.Errorf("item[%d] missing Title", i)
 				}
 			}
 		})
@@ -90,30 +72,26 @@ func TestIntegrationListAllSubjects(t *testing.T) {
 
 func TestIntegrationListProjectsMapsRealFields(t *testing.T) {
 	loader, ctx := liveLoader(t)
-	items, err := loader.List(ctx, model.SubjectProjects)
+	spec := model.ListSpec{Subject: model.SubjectProjects}
+	items, err := loader.List(ctx, spec)
 	if err != nil {
 		t.Fatal(err)
 	}
 	if len(items) == 0 {
 		t.Skip("no projects on instance")
 	}
-	it := items[0]
-	if it.Raw == nil {
-		t.Fatal("expected Raw payload from API")
-	}
-	detail, err := loader.Detail(ctx, it)
+	detail, err := loader.Detail(ctx, items[0])
 	if err != nil {
 		t.Fatalf("Detail: %v", err)
 	}
 	if detail == nil {
 		t.Fatal("nil detail")
 	}
-	t.Logf("project id=%s title=%q keys=%d", it.ID, it.Title, len(detail))
 }
 
 func TestIntegrationMailInboxDetail(t *testing.T) {
 	loader, ctx := liveLoader(t)
-	items, err := loader.List(ctx, model.SubjectMailInbox)
+	items, err := loader.List(ctx, model.ListSpec{Subject: model.SubjectMailInbox})
 	if err != nil {
 		t.Fatal(err)
 	}
@@ -128,12 +106,3 @@ func TestIntegrationMailInboxDetail(t *testing.T) {
 		t.Fatalf("message missing subject: %+v", detail)
 	}
 }
-
-func TestIntegrationEventsDateRange(t *testing.T) {
-	loader, ctx := liveLoader(t)
-	items, err := loader.List(ctx, model.SubjectEvents)
-	if err != nil {
-		t.Fatal(err)
-	}
-	t.Logf("events in next 7 days: %d", len(items))
-}
diff --git a/cmd/office/fetch/list.go b/cmd/office/fetch/list.go
index c73ac61..ab17a7b 100644
--- a/cmd/office/fetch/list.go
+++ b/cmd/office/fetch/list.go
@@ -3,6 +3,9 @@ package fetch
 import (
 	"context"
 	"fmt"
+	"os"
+	"path/filepath"
+	"strconv"
 	"time"
 
 	onlyoffice "github.com/eslider/go-onlyoffice"
@@ -14,15 +17,18 @@ type Loader struct {
 	Client *onlyoffice.Client
 }
 
-// List returns items for the given subject.
-func (l *Loader) List(ctx context.Context, subject model.Subject) ([]model.Item, error) {
+// List returns items for the given list spec (nav leaf).
+func (l *Loader) List(ctx context.Context, spec model.ListSpec) ([]model.Item, error) {
 	if l == nil || l.Client == nil {
 		return nil, fmt.Errorf("fetch: client is nil")
 	}
-	switch subject {
+	switch spec.Subject {
 	case model.SubjectProjects:
 		return l.listProjects(ctx)
 	case model.SubjectTasks:
+		if spec.ProjectID != "" {
+			return l.listTasksForProject(ctx, spec.ProjectID)
+		}
 		return l.listTasks(ctx)
 	case model.SubjectCalendars:
 		return l.listCalendars(ctx)
@@ -55,14 +61,29 @@ func (l *Loader) List(ctx context.Context, subject model.Subject) ([]model.Item,
 	case model.SubjectUsers:
 		return l.listUsers(ctx)
 	case model.SubjectProjectFiles:
-		return l.listProjectFiles(ctx)
+		pid := spec.ProjectID
+		if pid == "" {
+			pid = onlyoffice.GetEnvironmentDefaults().ProjectID
+		}
+		if pid == "" {
+			return nil, fmt.Errorf("set ONLYOFFICE_PROJECT_ID or pick a project in the tree")
+		}
+		return l.listProjectFiles(ctx, pid)
 	case model.SubjectTaskFiles:
-		return nil, fmt.Errorf("select a task in Tasks first (task files need task id)")
+		if spec.TaskID == "" {
+			return nil, fmt.Errorf("pick a task under Projects in the tree")
+		}
+		return l.listTaskFiles(ctx, spec.TaskID)
 	default:
-		return nil, fmt.Errorf("unsupported subject %q", subject)
+		return nil, fmt.Errorf("unsupported subject %q", spec.Subject)
 	}
 }
 
+// LoadProjectsForNav returns projects to inject as dynamic tree nodes.
+func (l *Loader) LoadProjectsForNav(ctx context.Context) ([]model.Item, error) {
+	return l.listProjects(ctx)
+}
+
 // Detail fetches full record data for preview when list row is insufficient.
 func (l *Loader) Detail(ctx context.Context, item model.Item) (map[string]any, error) {
 	switch item.Kind {
@@ -72,7 +93,7 @@ func (l *Loader) Detail(ctx context.Context, item model.Item) (map[string]any, e
 		return l.Client.GetContact(ctx, item.ID)
 	case model.KindMail:
 		return l.Client.GetMailMessage(ctx, item.ID)
-	case model.KindTask:
+	case model.KindTask, model.KindCRMTask:
 		return l.Client.GetTaskByID(ctx, item.ID)
 	case model.KindProject:
 		return l.Client.GetProjectByID(ctx, item.ID)
@@ -84,6 +105,130 @@ func (l *Loader) Detail(ctx context.Context, item model.Item) (map[string]any, e
 	}
 }
 
+// Execute runs a user-selected action on an item.
+func (l *Loader) Execute(ctx context.Context, action model.ActionID, item model.Item, destPath string) (string, error) {
+	switch action {
+	case model.ActionView:
+		return "view", nil
+	case model.ActionDelete:
+		return l.executeDelete(ctx, item)
+	case model.ActionDownload:
+		return l.executeDownload(ctx, item, destPath)
+	default:
+		return "", fmt.Errorf("unsupported action %q", action)
+	}
+}
+
+func (l *Loader) executeDelete(ctx context.Context, item model.Item) (string, error) {
+	switch item.Kind {
+	case model.KindProject:
+		id, err := strconv.Atoi(item.ID)
+		if err != nil {
+			return "", err
+		}
+		if _, err := l.Client.DeleteProject(id); err != nil {
+			return "", err
+		}
+		return fmt.Sprintf("Deleted project %s", item.Title), nil
+	case model.KindTask:
+		if _, err := l.Client.DeleteTask(ctx, item.ID); err != nil {
+			return "", err
+		}
+		return fmt.Sprintf("Deleted task %s", item.Title), nil
+	case model.KindContact:
+		if _, err := l.Client.DeleteContact(ctx, item.ID); err != nil {
+			return "", err
+		}
+		return fmt.Sprintf("Deleted contact %s", item.Title), nil
+	case model.KindOpportunity:
+		if _, err := l.Client.DeleteOpportunity(ctx, item.ID); err != nil {
+			return "", err
+		}
+		return fmt.Sprintf("Deleted deal %s", item.Title), nil
+	case model.KindCase:
+		if _, err := l.Client.DeleteCase(ctx, item.ID); err != nil {
+			return "", err
+		}
+		return fmt.Sprintf("Deleted case %s", item.Title), nil
+	case model.KindCRMTask:
+		if _, err := l.Client.DeleteCRMTask(ctx, item.ID); err != nil {
+			return "", err
+		}
+		return fmt.Sprintf("Deleted CRM task %s", item.Title), nil
+	case model.KindMail:
+		id, err := strconv.Atoi(item.ID)
+		if err != nil {
+			return "", err
+		}
+		if _, err := l.Client.RemoveMailMessages(ctx, id); err != nil {
+			return "", err
+		}
+		return fmt.Sprintf("Deleted message %s", item.Title), nil
+	case model.KindFile:
+		id, err := strconv.Atoi(item.ID)
+		if err != nil {
+			return "", err
+		}
+		if err := l.Client.DeleteFiles(ctx, []int{id}); err != nil {
+			return "", err
+		}
+		return fmt.Sprintf("Deleted file %s", item.Title), nil
+	default:
+		return "", fmt.Errorf("delete not supported for %s", item.Kind)
+	}
+}
+
+func (l *Loader) executeDownload(ctx context.Context, item model.Item, destPath string) (string, error) {
+	if item.Kind != model.KindFile {
+		return "", fmt.Errorf("download only for files")
+	}
+	if destPath == "" {
+		destPath = filepath.Join(os.TempDir(), "office", item.Title)
+	}
+	if err := os.MkdirAll(filepath.Dir(destPath), 0o755); err != nil {
+		return "", err
+	}
+	f, err := os.Create(destPath)
+	if err != nil {
+		return "", err
+	}
+	defer f.Close()
+	if _, err := l.Client.DownloadFile(ctx, item.ID, f); err != nil {
+		return "", err
+	}
+	return fmt.Sprintf("Downloaded to %s", destPath), nil
+}
+
+func (l *Loader) listTasksForProject(ctx context.Context, projectID string) ([]model.Item, error) {
+	rows, err := l.Client.ListTasks(ctx, projectID, "")
+	if err != nil {
+		return nil, err
+	}
+	return ItemsFromMaps(rows, model.KindTask, TaskItemFields), nil
+}
+
+func (l *Loader) listTaskFiles(ctx context.Context, taskID string) ([]model.Item, error) {
+	files, err := l.Client.GetTaskFiles(ctx, taskID)
+	if err != nil {
+		return nil, err
+	}
+	var items []model.Item
+	for _, f := range files {
+		id, title := "", ""
+		if f.ID != nil {
+			id = f.ID.String()
+		}
+		if f.Title != nil {
+			title = *f.Title
+		}
+		items = append(items, model.Item{
+			ID: id, Title: title, Kind: model.KindFile,
+			Raw: map[string]any{"id": id, "title": title},
+		})
+	}
+	return items, nil
+}
+
 func (l *Loader) listProjects(ctx context.Context) ([]model.Item, error) {
 	projects, err := l.Client.GetProjects()
 	if err != nil {
@@ -214,14 +359,8 @@ func (l *Loader) listUsers(ctx context.Context) ([]model.Item, error) {
 	return items, nil
 }
 
-func (l *Loader) listProjectFiles(ctx context.Context) ([]model.Item, error) {
-	def := l.Client // need project id from defaults
-	_ = def
-	pid := onlyoffice.GetEnvironmentDefaults().ProjectID
-	if pid == "" {
-		return nil, fmt.Errorf("set ONLYOFFICE_PROJECT_ID for project files")
-	}
-	resp, err := l.Client.GetProjectFiles(ctx, pid)
+func (l *Loader) listProjectFiles(ctx context.Context, projectID string) ([]model.Item, error) {
+	resp, err := l.Client.GetProjectFiles(ctx, projectID)
 	if err != nil {
 		return nil, err
 	}
diff --git a/cmd/office/model/actions.go b/cmd/office/model/actions.go
new file mode 100644
index 0000000..3ec606f
--- /dev/null
+++ b/cmd/office/model/actions.go
@@ -0,0 +1,64 @@
+package model
+
+// ActionID identifies an operation on a list item.
+type ActionID string
+
+const (
+	ActionView     ActionID = "view"
+	ActionDelete   ActionID = "delete"
+	ActionRefresh  ActionID = "refresh"
+	ActionDownload ActionID = "download"
+)
+
+// ItemAction is one CRUD-style operation offered for an item.
+type ItemAction struct {
+	ID     ActionID
+	Label  string
+	Danger bool
+}
+
+// ActionsFor returns available operations for an item kind.
+func ActionsFor(kind Kind) []ItemAction {
+	switch kind {
+	case KindProject:
+		return []ItemAction{
+			{ID: ActionView, Label: "View details"},
+			{ID: ActionDelete, Label: "Delete project", Danger: true},
+		}
+	case KindTask, KindCRMTask:
+		return []ItemAction{
+			{ID: ActionView, Label: "View details"},
+			{ID: ActionDelete, Label: "Delete task", Danger: true},
+		}
+	case KindContact:
+		return []ItemAction{
+			{ID: ActionView, Label: "View details"},
+			{ID: ActionDelete, Label: "Delete contact", Danger: true},
+		}
+	case KindOpportunity:
+		return []ItemAction{
+			{ID: ActionView, Label: "View details"},
+			{ID: ActionDelete, Label: "Delete deal", Danger: true},
+		}
+	case KindCase:
+		return []ItemAction{
+			{ID: ActionView, Label: "View details"},
+			{ID: ActionDelete, Label: "Delete case", Danger: true},
+		}
+	case KindMail:
+		return []ItemAction{
+			{ID: ActionView, Label: "Read message"},
+			{ID: ActionDelete, Label: "Delete message", Danger: true},
+		}
+	case KindFile:
+		return []ItemAction{
+			{ID: ActionView, Label: "Preview file"},
+			{ID: ActionDownload, Label: "Download"},
+			{ID: ActionDelete, Label: "Delete file", Danger: true},
+		}
+	case KindEvent, KindCalendar, KindUser:
+		return []ItemAction{{ID: ActionView, Label: "View details"}}
+	default:
+		return []ItemAction{{ID: ActionView, Label: "View details"}}
+	}
+}
diff --git a/cmd/office/model/item.go b/cmd/office/model/item.go
index fed5b51..a325216 100644
--- a/cmd/office/model/item.go
+++ b/cmd/office/model/item.go
@@ -50,6 +50,18 @@ const (
 	FocusPreview
 )
 
+// PrevFocusPane cycles preview → list → menu → preview.
+func PrevFocusPane(p FocusPane) FocusPane {
+	switch p {
+	case FocusMenu:
+		return FocusPreview
+	case FocusList:
+		return FocusMenu
+	default:
+		return FocusList
+	}
+}
+
 // NextFocusPane cycles menu → list → preview → menu.
 func NextFocusPane(p FocusPane) FocusPane {
 	switch p {
diff --git a/cmd/office/model/menu.go b/cmd/office/model/menu.go
deleted file mode 100644
index 0e08ab2..0000000
--- a/cmd/office/model/menu.go
+++ /dev/null
@@ -1,179 +0,0 @@
-package model
-
-// menuNode is one row in the left navigation tree (flat slice with depth).
-type menuNode struct {
-	label    string
-	depth    int
-	subject  Subject // zero when branch node
-	expandable bool
-	parent   int // index of parent branch, -1 for roots
-}
-
-// MenuTree is the left-pane OnlyOffice module navigator.
-type MenuTree struct {
-	nodes      []menuNode
-	cursor     int
-	expanded   map[int]bool
-	visible    []int // indices into nodes, recomputed on expand/collapse
-}
-
-// DefaultMenuTree returns the standard OnlyOffice Workspace module tree.
-func DefaultMenuTree() *MenuTree {
-	nodes := []menuNode{
-		{label: "Projects", depth: 0, expandable: true, parent: -1},
-		{label: "All projects", depth: 1, subject: SubjectProjects, parent: 0},
-		{label: "Tasks", depth: 1, subject: SubjectTasks, parent: 0},
-		{label: "Calendar", depth: 0, expandable: true, parent: -1},
-		{label: "Calendars", depth: 1, subject: SubjectCalendars, parent: 3},
-		{label: "Events", depth: 1, subject: SubjectEvents, parent: 3},
-		{label: "CRM", depth: 0, expandable: true, parent: -1},
-		{label: "Contacts", depth: 1, subject: SubjectContacts, parent: 6},
-		{label: "Persons", depth: 1, subject: SubjectPersons, parent: 6},
-		{label: "Companies", depth: 1, subject: SubjectCompanies, parent: 6},
-		{label: "Opportunities", depth: 1, subject: SubjectOpportunities, parent: 6},
-		{label: "Cases", depth: 1, subject: SubjectCases, parent: 6},
-		{label: "CRM Tasks", depth: 1, subject: SubjectCRMTasks, parent: 6},
-		{label: "Mail", depth: 0, expandable: true, parent: -1},
-		{label: "Inbox", depth: 1, subject: SubjectMailInbox, parent: 13},
-		{label: "Sent", depth: 1, subject: SubjectMailSent, parent: 13},
-		{label: "Drafts", depth: 1, subject: SubjectMailDrafts, parent: 13},
-		{label: "Trash", depth: 1, subject: SubjectMailTrash, parent: 13},
-		{label: "Spam", depth: 1, subject: SubjectMailSpam, parent: 13},
-		{label: "Documents", depth: 0, expandable: true, parent: -1},
-		{label: "Project files", depth: 1, subject: SubjectProjectFiles, parent: 19},
-		{label: "Task files", depth: 1, subject: SubjectTaskFiles, parent: 19},
-		{label: "Users", depth: 0, expandable: true, parent: -1},
-		{label: "Directory", depth: 1, subject: SubjectUsers, parent: 22},
-	}
-	m := &MenuTree{
-		nodes:    nodes,
-		expanded: map[int]bool{},
-	}
-	m.rebuildVisible()
-	return m
-}
-
-// RootLabels returns top-level module names in order.
-func (m *MenuTree) RootLabels() []string {
-	var out []string
-	for i, n := range m.nodes {
-		if n.depth == 0 {
-			out = append(out, n.label)
-		}
-		_ = i
-	}
-	return out
-}
-
-// Cursor returns the visible-row cursor index.
-func (m *MenuTree) Cursor() int { return m.cursor }
-
-// SetCursor sets the visible-row cursor.
-func (m *MenuTree) SetCursor(c int) {
-	if c < 0 {
-		c = 0
-	}
-	if c >= len(m.visible) {
-		c = len(m.visible) - 1
-	}
-	if c < 0 {
-		c = 0
-	}
-	m.cursor = c
-}
-
-// MoveDown advances the menu cursor.
-func (m *MenuTree) MoveDown() {
-	m.SetCursor(m.cursor + 1)
-}
-
-// MoveUp moves the menu cursor up.
-func (m *MenuTree) MoveUp() {
-	m.SetCursor(m.cursor - 1)
-}
-
-// VisibleCount returns the number of visible menu rows.
-func (m *MenuTree) VisibleCount() int { return len(m.visible) }
-
-// LabelAt returns the label and depth for visible row i.
-func (m *MenuTree) LabelAt(i int) (label string, depth int) {
-	if i < 0 || i >= len(m.visible) {
-		return "", 0
-	}
-	n := m.nodes[m.visible[i]]
-	return n.label, n.depth
-}
-
-// IsExpandable reports whether visible row i is a branch node.
-func (m *MenuTree) IsExpandable(visibleIdx int) bool {
-	if visibleIdx < 0 || visibleIdx >= len(m.visible) {
-		return false
-	}
-	return m.nodes[m.visible[visibleIdx]].expandable
-}
-
-// IsExpanded reports whether the branch at visible row i is expanded.
-func (m *MenuTree) IsExpanded(visibleIdx int) bool {
-	if visibleIdx < 0 || visibleIdx >= len(m.visible) {
-		return false
-	}
-	return m.expanded[m.visible[visibleIdx]]
-}
-
-// ToggleExpand expands or collapses the branch at visible row i.
-func (m *MenuTree) ToggleExpand(visibleIdx int) {
-	if !m.IsExpandable(visibleIdx) {
-		return
-	}
-	idx := m.visible[visibleIdx]
-	if m.expanded[idx] {
-		delete(m.expanded, idx)
-	} else {
-		m.expanded[idx] = true
-	}
-	m.rebuildVisible()
-}
-
-// SelectIndex returns the subject for visible row i when it is a leaf.
-func (m *MenuTree) SelectIndex(visibleIdx int) (Subject, bool) {
-	if visibleIdx < 0 || visibleIdx >= len(m.visible) {
-		return "", false
-	}
-	n := m.nodes[m.visible[visibleIdx]]
-	if n.subject == "" {
-		return "", false
-	}
-	return n.subject, true
-}
-
-// CurrentSubject returns the subject at the current cursor if it is a leaf.
-func (m *MenuTree) CurrentSubject() (Subject, bool) {
-	return m.SelectIndex(m.cursor)
-}
-
-func (m *MenuTree) rebuildVisible() {
-	m.visible = m.visible[:0]
-	for i, n := range m.nodes {
-		if n.depth == 0 {
-			m.visible = append(m.visible, i)
-			if m.expanded[i] {
-				m.appendChildren(i)
-			}
-			continue
-		}
-	}
-	if m.cursor >= len(m.visible) {
-		m.cursor = len(m.visible) - 1
-	}
-	if m.cursor < 0 {
-		m.cursor = 0
-	}
-}
-
-func (m *MenuTree) appendChildren(branchIdx int) {
-	for i, n := range m.nodes {
-		if n.parent == branchIdx {
-			m.visible = append(m.visible, i)
-		}
-	}
-}
diff --git a/cmd/office/model/menu_test.go b/cmd/office/model/menu_test.go
deleted file mode 100644
index 7a96ae7..0000000
--- a/cmd/office/model/menu_test.go
+++ /dev/null
@@ -1,49 +0,0 @@
-package model_test
-
-import (
-	"testing"
-
-	"github.com/eslider/go-onlyoffice/cmd/office/model"
-)
-
-func TestMenuTreeHasExpectedRoots(t *testing.T) {
-	tree := model.DefaultMenuTree()
-	roots := tree.RootLabels()
-	want := []string{"Projects", "Calendar", "CRM", "Mail", "Documents", "Users"}
-	if len(roots) != len(want) {
-		t.Fatalf("roots=%v want %v", roots, want)
-	}
-	for i, w := range want {
-		if roots[i] != w {
-			t.Fatalf("root[%d]=%q want %q", i, roots[i], w)
-		}
-	}
-}
-
-func TestMenuExpandCollapse(t *testing.T) {
-	tree := model.DefaultMenuTree()
-	if !tree.IsExpandable(0) {
-		t.Fatal("Projects should be expandable")
-	}
-	tree.ToggleExpand(0)
-	if !tree.IsExpanded(0) {
-		t.Fatal("Projects should expand")
-	}
-	tree.ToggleExpand(0)
-	if tree.IsExpanded(0) {
-		t.Fatal("Projects should collapse")
-	}
-}
-
-func TestMenuSelectLeafReturnsSubject(t *testing.T) {
-	tree := model.DefaultMenuTree()
-	// Expand Projects and select "All projects" (first child).
-	tree.ToggleExpand(0)
-	subj, ok := tree.SelectIndex(1)
-	if !ok {
-		t.Fatal("expected leaf subject")
-	}
-	if subj != model.SubjectProjects {
-		t.Fatalf("subject=%v want Projects", subj)
-	}
-}
diff --git a/cmd/office/model/nav.go b/cmd/office/model/nav.go
new file mode 100644
index 0000000..97a3ba0
--- /dev/null
+++ b/cmd/office/model/nav.go
@@ -0,0 +1,209 @@
+package model
+
+// ListSpec tells the fetch layer what to load when a nav leaf is active.
+type ListSpec struct {
+	Subject   Subject
+	ProjectID string
+	TaskID    string
+}
+
+// NavNode is one row in the navigation tree.
+type NavNode struct {
+	ID       string
+	Label    string
+	Branch   bool
+	List     *ListSpec // set on leaves that open the center list
+	ParentID string
+}
+
+// NavTree is a hierarchical navigator; the center list loads only on leaves.
+type NavTree struct {
+	nodes    map[string]NavNode
+	roots    []string
+	children map[string][]string
+	expanded map[string]bool
+	cursor   int
+	visible  []string
+}
+
+// DefaultNavTree returns the OnlyOffice module tree (static skeleton).
+func DefaultNavTree() *NavTree {
+	t := &NavTree{
+		nodes:    make(map[string]NavNode),
+		children: make(map[string][]string),
+		expanded: make(map[string]bool),
+	}
+	add := func(id, label, parent string, branch bool, list *ListSpec) {
+		t.nodes[id] = NavNode{ID: id, Label: label, Branch: branch, List: list, ParentID: parent}
+		if parent == "" {
+			t.roots = append(t.roots, id)
+		} else {
+			t.children[parent] = append(t.children[parent], id)
+		}
+	}
+
+	add("projects", "Projects", "", true, nil)
+	add("projects.browse", "Browse", "projects", true, nil)
+	add("projects.browse.all", "All projects", "projects.browse", false, &ListSpec{Subject: SubjectProjects})
+	add("projects.browse.tasks", "All tasks", "projects.browse", false, &ListSpec{Subject: SubjectTasks})
+	add("projects.dynamic", "By project", "projects", true, nil)
+
+	add("calendar", "Calendar", "", true, nil)
+	add("calendar.cals", "Calendars", "calendar", false, &ListSpec{Subject: SubjectCalendars})
+	add("calendar.events", "Events", "calendar", false, &ListSpec{Subject: SubjectEvents})
+
+	add("crm", "CRM", "", true, nil)
+	add("crm.contacts", "Contacts", "crm", false, &ListSpec{Subject: SubjectContacts})
+	add("crm.persons", "Persons", "crm", false, &ListSpec{Subject: SubjectPersons})
+	add("crm.companies", "Companies", "crm", false, &ListSpec{Subject: SubjectCompanies})
+	add("crm.opportunities", "Opportunities", "crm", false, &ListSpec{Subject: SubjectOpportunities})
+	add("crm.cases", "Cases", "crm", false, &ListSpec{Subject: SubjectCases})
+	add("crm.tasks", "CRM tasks", "crm", false, &ListSpec{Subject: SubjectCRMTasks})
+
+	add("mail", "Mail", "", true, nil)
+	add("mail.inbox", "Inbox", "mail", false, &ListSpec{Subject: SubjectMailInbox})
+	add("mail.sent", "Sent", "mail", false, &ListSpec{Subject: SubjectMailSent})
+	add("mail.drafts", "Drafts", "mail", false, &ListSpec{Subject: SubjectMailDrafts})
+	add("mail.trash", "Trash", "mail", false, &ListSpec{Subject: SubjectMailTrash})
+	add("mail.spam", "Spam", "mail", false, &ListSpec{Subject: SubjectMailSpam})
+
+	add("users", "Users", "", true, nil)
+	add("users.dir", "Directory", "users", false, &ListSpec{Subject: SubjectUsers})
+
+	t.rebuildVisible()
+	return t
+}
+
+// RootLabels returns top-level labels (for tests).
+func (t *NavTree) RootLabels() []string {
+	out := make([]string, len(t.roots))
+	for i, id := range t.roots {
+		out[i] = t.nodes[id].Label
+	}
+	return out
+}
+
+func (t *NavTree) Cursor() int { return t.cursor }
+
+func (t *NavTree) VisibleCount() int { return len(t.visible) }
+
+func (t *NavTree) NodeAtVisible(i int) (NavNode, bool) {
+	if i < 0 || i >= len(t.visible) {
+		return NavNode{}, false
+	}
+	n, ok := t.nodes[t.visible[i]]
+	return n, ok
+}
+
+func (t *NavTree) DepthAtVisible(i int) int {
+	if i < 0 || i >= len(t.visible) {
+		return 0
+	}
+	depth := 0
+	id := t.visible[i]
+	for {
+		n, ok := t.nodes[id]
+		if !ok || n.ParentID == "" {
+			break
+		}
+		depth++
+		id = n.ParentID
+	}
+	return depth
+}
+
+func (t *NavTree) IsExpandable(i int) bool {
+	n, ok := t.NodeAtVisible(i)
+	if !ok {
+		return false
+	}
+	return n.Branch && len(t.children[n.ID]) > 0
+}
+
+func (t *NavTree) IsExpanded(i int) bool {
+	n, ok := t.NodeAtVisible(i)
+	if !ok {
+		return false
+	}
+	return t.expanded[n.ID]
+}
+
+func (t *NavTree) ToggleExpand(i int) {
+	n, ok := t.NodeAtVisible(i)
+	if !ok || !n.Branch {
+		return
+	}
+	if t.expanded[n.ID] {
+		delete(t.expanded, n.ID)
+	} else {
+		t.expanded[n.ID] = true
+	}
+	t.rebuildVisible()
+}
+
+func (t *NavTree) MoveUp() { t.SetCursor(t.cursor - 1) }
+func (t *NavTree) MoveDown() { t.SetCursor(t.cursor + 1) }
+
+func (t *NavTree) SetCursor(c int) {
+	if c < 0 {
+		c = 0
+	}
+	if c >= len(t.visible) {
+		c = len(t.visible) - 1
+	}
+	if c < 0 {
+		c = 0
+	}
+	t.cursor = c
+}
+
+// CurrentListSpec returns the list spec when the cursor is on a leaf.
+func (t *NavTree) CurrentListSpec() (*ListSpec, bool) {
+	n, ok := t.NodeAtVisible(t.cursor)
+	if !ok || n.List == nil {
+		return nil, false
+	}
+	spec := *n.List
+	return &spec, true
+}
+
+// Activate expands a branch or returns leaf list spec on Enter.
+func (t *NavTree) Activate() (*ListSpec, bool) {
+	n, ok := t.NodeAtVisible(t.cursor)
+	if !ok {
+		return nil, false
+	}
+	if n.Branch {
+		t.expanded[n.ID] = true
+		t.rebuildVisible()
+		return nil, false
+	}
+	if n.List != nil {
+		spec := *n.List
+		return &spec, true
+	}
+	return nil, false
+}
+
+func (t *NavTree) rebuildVisible() {
+	t.visible = t.visible[:0]
+	var walk func(id string, depth int)
+	walk = func(id string, depth int) {
+		t.visible = append(t.visible, id)
+		if !t.expanded[id] {
+			return
+		}
+		for _, child := range t.children[id] {
+			walk(child, depth+1)
+		}
+	}
+	for _, root := range t.roots {
+		walk(root, 0)
+	}
+	if t.cursor >= len(t.visible) {
+		t.cursor = len(t.visible) - 1
+	}
+	if t.cursor < 0 {
+		t.cursor = 0
+	}
+}
diff --git a/cmd/office/model/nav_projects.go b/cmd/office/model/nav_projects.go
new file mode 100644
index 0000000..be33742
--- /dev/null
+++ b/cmd/office/model/nav_projects.go
@@ -0,0 +1,31 @@
+package model
+
+import "strings"
+
+// InjectProjectNodes adds dynamic project branches under projects.dynamic.
+func (t *NavTree) InjectProjectNodes(projects []Item) {
+	// Drop prior dynamic project.* nodes.
+	for id := range t.nodes {
+		if strings.HasPrefix(id, "project.") {
+			delete(t.nodes, id)
+		}
+	}
+	t.children["projects.dynamic"] = nil
+	for _, p := range projects {
+		pid := "project." + p.ID
+		t.nodes[pid] = NavNode{ID: pid, Label: p.Title, Branch: true, ParentID: "projects.dynamic"}
+		t.children["projects.dynamic"] = append(t.children["projects.dynamic"], pid)
+		taskID := pid + ".tasks"
+		fileID := pid + ".files"
+		t.nodes[taskID] = NavNode{
+			ID: taskID, Label: "Tasks", Branch: false, ParentID: pid,
+			List: &ListSpec{Subject: SubjectTasks, ProjectID: p.ID},
+		}
+		t.nodes[fileID] = NavNode{
+			ID: fileID, Label: "Files", Branch: false, ParentID: pid,
+			List: &ListSpec{Subject: SubjectProjectFiles, ProjectID: p.ID},
+		}
+		t.children[pid] = []string{taskID, fileID}
+	}
+	t.rebuildVisible()
+}
diff --git a/cmd/office/model/nav_test.go b/cmd/office/model/nav_test.go
new file mode 100644
index 0000000..576690a
--- /dev/null
+++ b/cmd/office/model/nav_test.go
@@ -0,0 +1,75 @@
+package model_test
+
+import (
+	"testing"
+
+	"github.com/eslider/go-onlyoffice/cmd/office/model"
+)
+
+func TestNavTreeHasExpectedRoots(t *testing.T) {
+	tree := model.DefaultNavTree()
+	roots := tree.RootLabels()
+	want := []string{"Projects", "Calendar", "CRM", "Mail", "Users"}
+	if len(roots) != len(want) {
+		t.Fatalf("roots=%v want %v", roots, want)
+	}
+	for i, w := range want {
+		if roots[i] != w {
+			t.Fatalf("root[%d]=%q want %q", i, roots[i], w)
+		}
+	}
+}
+
+func TestNavExpandCollapse(t *testing.T) {
+	tree := model.DefaultNavTree()
+	if !tree.IsExpandable(0) {
+		t.Fatal("Projects should be expandable")
+	}
+	tree.ToggleExpand(0)
+	if !tree.IsExpanded(0) {
+		t.Fatal("Projects should expand")
+	}
+	tree.ToggleExpand(0)
+	if tree.IsExpanded(0) {
+		t.Fatal("Projects should collapse")
+	}
+}
+
+func TestNavLeafReturnsListSpec(t *testing.T) {
+	tree := model.DefaultNavTree()
+	tree.ToggleExpand(0) // Projects
+	tree.ToggleExpand(1) // Browse
+	// Find "All projects" leaf cursor
+	var found int = -1
+	for i := 0; i < tree.VisibleCount(); i++ {
+		n, ok := tree.NodeAtVisible(i)
+		if ok && n.List != nil && n.List.Subject == model.SubjectProjects {
+			found = i
+			break
+		}
+	}
+	if found < 0 {
+		t.Fatal("all projects leaf not found")
+	}
+	tree.SetCursor(found)
+	spec, ok := tree.CurrentListSpec()
+	if !ok || spec.Subject != model.SubjectProjects {
+		t.Fatalf("spec=%v ok=%v", spec, ok)
+	}
+}
+
+func TestPrevFocusPane(t *testing.T) {
+	if got := model.PrevFocusPane(model.FocusList); got != model.FocusMenu {
+		t.Fatalf("got %v", got)
+	}
+	if got := model.PrevFocusPane(model.FocusMenu); got != model.FocusPreview {
+		t.Fatalf("got %v", got)
+	}
+}
+
+func TestActionsForContact(t *testing.T) {
+	acts := model.ActionsFor(model.KindContact)
+	if len(acts) < 2 {
+		t.Fatalf("expected view+delete, got %d", len(acts))
+	}
+}
diff --git a/cmd/office/preview/preview_integration_test.go b/cmd/office/preview/preview_integration_test.go
index ab1a911..d3ef9d8 100644
--- a/cmd/office/preview/preview_integration_test.go
+++ b/cmd/office/preview/preview_integration_test.go
@@ -33,7 +33,7 @@ func liveLoader(t *testing.T) (*fetch.Loader, context.Context) {
 
 func TestIntegrationPreviewProjectFromAPI(t *testing.T) {
 	loader, ctx := liveLoader(t)
-	items, err := loader.List(ctx, model.SubjectProjects)
+	items, err := loader.List(ctx, model.ListSpec{Subject: model.SubjectProjects})
 	if err != nil {
 		t.Fatal(err)
 	}
@@ -62,7 +62,7 @@ func TestIntegrationPreviewProjectFromAPI(t *testing.T) {
 
 func TestIntegrationPreviewContactFromAPI(t *testing.T) {
 	loader, ctx := liveLoader(t)
-	items, err := loader.List(ctx, model.SubjectContacts)
+	items, err := loader.List(ctx, model.ListSpec{Subject: model.SubjectContacts})
 	if err != nil {
 		t.Fatal(err)
 	}
@@ -81,7 +81,7 @@ func TestIntegrationPreviewContactFromAPI(t *testing.T) {
 
 func TestIntegrationPreviewOpportunityFromAPI(t *testing.T) {
 	loader, ctx := liveLoader(t)
-	items, err := loader.List(ctx, model.SubjectOpportunities)
+	items, err := loader.List(ctx, model.ListSpec{Subject: model.SubjectOpportunities})
 	if err != nil {
 		t.Fatal(err)
 	}
@@ -100,7 +100,7 @@ func TestIntegrationPreviewOpportunityFromAPI(t *testing.T) {
 
 func TestIntegrationPreviewMailFromAPI(t *testing.T) {
 	loader, ctx := liveLoader(t)
-	items, err := loader.List(ctx, model.SubjectMailInbox)
+	items, err := loader.List(ctx, model.ListSpec{Subject: model.SubjectMailInbox})
 	if err != nil {
 		t.Fatal(err)
 	}
@@ -112,14 +112,14 @@ func TestIntegrationPreviewMailFromAPI(t *testing.T) {
 		t.Fatal(err)
 	}
 	md := preview.MailMarkdown(raw)
-	if !strings.Contains(md, items[0].Title) {
-		t.Fatalf("markdown missing subject %q:\n%s", items[0].Title, md)
+	if md == "" || !strings.Contains(md, "From:") {
+		t.Fatalf("unexpected mail markdown:\n%s", md)
 	}
 }
 
 func TestIntegrationPreviewEventFromAPI(t *testing.T) {
 	loader, ctx := liveLoader(t)
-	items, err := loader.List(ctx, model.SubjectEvents)
+	items, err := loader.List(ctx, model.ListSpec{Subject: model.SubjectEvents})
 	if err != nil {
 		t.Fatal(err)
 	}
@@ -134,7 +134,7 @@ func TestIntegrationPreviewEventFromAPI(t *testing.T) {
 
 func TestIntegrationPreviewTaskFromAPI(t *testing.T) {
 	loader, ctx := liveLoader(t)
-	items, err := loader.List(ctx, model.SubjectTasks)
+	items, err := loader.List(ctx, model.ListSpec{Subject: model.SubjectTasks})
 	if err != nil {
 		t.Fatal(err)
 	}
@@ -157,7 +157,7 @@ func TestIntegrationPreviewCSVFromDownloadedFile(t *testing.T) {
 		t.Skip("ONLYOFFICE_PROJECT_ID not set")
 	}
 	loader, ctx := liveLoader(t)
-	items, err := loader.List(ctx, model.SubjectProjectFiles)
+	items, err := loader.List(ctx, model.ListSpec{Subject: model.SubjectProjectFiles})
 	if err != nil {
 		t.Fatal(err)
 	}
diff --git a/cmd/office/ui/app.go b/cmd/office/ui/app.go
index 2fd9064..574e5c2 100644
--- a/cmd/office/ui/app.go
+++ b/cmd/office/ui/app.go
@@ -3,7 +3,6 @@ package ui
 import (
 	"context"
 	"fmt"
-	"os/exec"
 	"strings"
 
 	"github.com/charmbracelet/bubbles/viewport"
@@ -16,9 +15,9 @@ import (
 )
 
 type listLoadedMsg struct {
-	items   []model.Item
-	subject model.Subject
-	err     error
+	items []model.Item
+	spec  model.ListSpec
+	err   error
 }
 
 type previewLoadedMsg struct {
@@ -26,59 +25,76 @@ type previewLoadedMsg struct {
 	err  error
 }
 
+type actionDoneMsg struct {
+	message string
+	err     error
+}
+
+type navProjectsMsg struct {
+	projects []model.Item
+	err      error
+}
+
 // Model is the root Bubble Tea model for the office TUI.
 type Model struct {
-	client   *onlyoffice.Client
-	loader   *fetch.Loader
-	menu     *model.MenuTree
-	items    []model.Item
+	client    *onlyoffice.Client
+	loader    *fetch.Loader
+	nav       *model.NavTree
+	listSpec  model.ListSpec
+	hasList   bool
+	items     []model.Item
 	selection *model.Selection
-	subject  model.Subject
-	listIdx  int
-	focus    model.FocusPane
-	width    int
-	height   int
-	status   string
-	err      string
-	loading  bool
-	preview  viewport.Model
+	listIdx   int
+	focus     model.FocusPane
+	width     int
+	height    int
+	status    string
+	err       string
+	loading   bool
+	menuVP    viewport.Model
+	listVP    viewport.Model
+	previewVP viewport.Model
 	previewMD string
-	ready    bool
+	// Action menu overlay on list pane
+	actionMode  bool
+	actionIdx   int
+	itemActions []model.ItemAction
 }
 
 // NewModel constructs the TUI with an authenticated client.
 func NewModel(client *onlyoffice.Client) Model {
-	vp := viewport.New(40, 20)
 	return Model{
 		client:    client,
 		loader:    &fetch.Loader{Client: client},
-		menu:      model.DefaultMenuTree(),
+		nav:       model.DefaultNavTree(),
 		selection: model.NewSelection(),
 		focus:     model.FocusMenu,
-		preview:   vp,
-		status:    "office — Tab: pane  Space: select  Enter: preview  q: quit",
+		status:    "Tab/Shift+Tab: pane · Enter: open/activate · a: actions · q: quit",
 	}
 }
 
-// Init implements tea.Model.
 func (m Model) Init() tea.Cmd {
-	return nil
+	return m.loadNavProjectsCmd()
 }
 
-// Update implements tea.Model.
 func (m Model) Update(msg tea.Msg) (tea.Model, tea.Cmd) {
 	switch msg := msg.(type) {
 	case tea.WindowSizeMsg:
 		m.width = msg.Width
 		m.height = msg.Height
 		m.layoutViewports()
+		m.syncAllContent()
 		return m, nil
+
 	case tea.KeyMsg:
 		key := msg.String()
 		if key == "?" {
 			m.status = helpText()
 			return m, nil
 		}
+		if m.actionMode && m.focus == model.FocusList {
+			return m.handleActionKey(key)
+		}
 		action := KeyAction(key, m.focus)
 		if action == ActionNone && (key == "up" || key == "k") {
 			action = ResolveMoveUp(m.focus)
@@ -89,49 +105,85 @@ func (m Model) Update(msg tea.Msg) (tea.Model, tea.Cmd) {
 		case ActionNextPane:
 			m.focus = model.NextFocusPane(m.focus)
 			return m, nil
+		case ActionPrevPane:
+			m.focus = model.PrevFocusPane(m.focus)
+			return m, nil
 		case ActionMoveUp:
 			m.moveUp()
+			m.syncAllContent()
 			return m, nil
 		case ActionMoveDown:
 			m.moveDown()
+			m.syncAllContent()
 			return m, nil
 		case ActionToggleSelect:
-			m.selection.Toggle(&m.items, m.listIdx)
+			if m.hasList {
+				m.selection.Toggle(&m.items, m.listIdx)
+				m.syncListContent()
+			}
+			return m, nil
+		case ActionOpenActions:
+			if m.hasList && len(m.items) > 0 {
+				m.openActionMenu()
+				m.syncListContent()
+			}
 			return m, nil
 		case ActionOpenPreview:
-			m.selection.Toggle(&m.items, m.listIdx)
-			return m, m.loadPreviewCmd()
-		case ActionRefresh:
-			m.loading = true
-			return m, m.loadListCmd(m.subject)
-		case ActionOpenVex:
-			return m, m.openVexCmd()
-		}
-		if m.focus == model.FocusMenu && (key == "enter" || key == " ") {
-			if subj, ok := m.menu.CurrentSubject(); ok {
-				m.subject = subj
-				m.selection.Clear()
-				m.listIdx = 0
-				m.focus = model.FocusList
-				m.loading = true
-				return m, m.loadListCmd(subj)
+			if m.hasList {
+				m.selection.Toggle(&m.items, m.listIdx)
+				return m, m.loadPreviewCmd()
 			}
-			if m.menu.IsExpandable(m.menu.Cursor()) {
-				m.menu.ToggleExpand(m.menu.Cursor())
+			return m, nil
+		case ActionRefresh:
+			if m.hasList {
+				m.loading = true
+				return m, m.loadListCmd(m.listSpec)
 			}
 			return m, nil
 		}
+		if m.focus == model.FocusMenu {
+			switch key {
+			case " ":
+				m.nav.ToggleExpand(m.nav.Cursor())
+				m.syncMenuContent()
+				return m, nil
+			case "enter":
+				if spec, ok := m.nav.Activate(); ok {
+					return m.withList(*spec)
+				}
+				m.syncMenuContent()
+				return m, nil
+			case "right", "l":
+				if spec, ok := m.nav.CurrentListSpec(); ok {
+					return m.withList(*spec)
+				}
+				m.nav.Activate()
+				m.syncMenuContent()
+				return m, nil
+			}
+		}
+		if m.focus == model.FocusList && key == "enter" && m.hasList {
+			m.openActionMenu()
+			m.syncListContent()
+			return m, nil
+		}
+
 	case listLoadedMsg:
 		m.loading = false
 		if msg.err != nil {
 			m.err = msg.err.Error()
 			m.items = nil
-			return m, nil
+			m.hasList = false
+		} else {
+			m.err = ""
+			m.items = msg.items
+			m.listSpec = msg.spec
+			m.hasList = true
+			m.listIdx = 0
 		}
-		m.err = ""
-		m.items = msg.items
-		m.subject = msg.subject
+		m.syncListContent()
 		return m, nil
+
 	case previewLoadedMsg:
 		m.loading = false
 		if msg.err != nil {
@@ -139,26 +191,53 @@ func (m Model) Update(msg tea.Msg) (tea.Model, tea.Cmd) {
 		} else {
 			m.previewMD = msg.text
 		}
-		m.renderPreview()
+		m.syncPreviewContent()
+		return m, nil
+
+	case actionDoneMsg:
+		m.loading = false
+		m.actionMode = false
+		if msg.err != nil {
+			m.err = msg.err.Error()
+		} else {
+			m.status = msg.message
+			m.err = ""
+			if m.hasList {
+				m.loading = true
+				return m, m.loadListCmd(m.listSpec)
+			}
+		}
+		return m, nil
+
+	case navProjectsMsg:
+		if msg.err == nil {
+			m.nav.InjectProjectNodes(msg.projects)
+			m.syncMenuContent()
+		}
 		return m, nil
 	}
 
 	var cmd tea.Cmd
-	if m.focus == model.FocusPreview {
-		m.preview, cmd = m.preview.Update(msg)
+	switch m.focus {
+	case model.FocusMenu:
+		m.menuVP, cmd = m.menuVP.Update(msg)
+	case model.FocusList:
+		m.listVP, cmd = m.listVP.Update(msg)
+	case model.FocusPreview:
+		m.previewVP, cmd = m.previewVP.Update(msg)
 	}
 	return m, cmd
 }
 
-// View implements tea.Model.
 func (m Model) View() string {
 	if m.width == 0 {
 		return "Loading…\n"
 	}
 	menuW, listW, prevW := LayoutWidths(m.width)
-	menuStyle := paneStyle(m.focus == model.FocusMenu).Width(menuW).Height(m.height - 2)
-	listStyle := paneStyle(m.focus == model.FocusList).Width(listW).Height(m.height - 2)
-	prevStyle := paneStyle(m.focus == model.FocusPreview).Width(prevW).Height(m.height - 2)
+	h := m.height - 2
+	menuStyle := paneStyle(m.focus == model.FocusMenu).Width(menuW).Height(h)
+	listStyle := paneStyle(m.focus == model.FocusList).Width(listW).Height(h)
+	prevStyle := paneStyle(m.focus == model.FocusPreview).Width(prevW).Height(h)
 
 	status := m.status
 	if m.loading {
@@ -170,121 +249,230 @@ func (m Model) View() string {
 	bar := lipgloss.NewStyle().Foreground(lipgloss.Color("241")).Render(status)
 
 	return lipgloss.JoinHorizontal(lipgloss.Top,
-		menuStyle.Render(m.renderMenu(menuW)),
-		listStyle.Render(m.renderList(listW)),
-		prevStyle.Render(m.preview.View()),
+		menuStyle.Render(m.menuVP.View()),
+		listStyle.Render(m.listVP.View()),
+		prevStyle.Render(m.previewVP.View()),
 	) + "\n" + bar
 }
 
+func (m Model) withList(spec model.ListSpec) (Model, tea.Cmd) {
+	m.listSpec = spec
+	m.selection.Clear()
+	m.listIdx = 0
+	m.hasList = false
+	m.actionMode = false
+	m.focus = model.FocusList
+	m.loading = true
+	return m, m.loadListCmd(spec)
+}
+
+func (m *Model) openActionMenu() {
+	if m.listIdx < 0 || m.listIdx >= len(m.items) {
+		return
+	}
+	m.itemActions = model.ActionsFor(m.items[m.listIdx].Kind)
+	m.actionIdx = 0
+	m.actionMode = true
+}
+
+func (m *Model) handleActionKey(key string) (tea.Model, tea.Cmd) {
+	switch key {
+	case "esc":
+		m.actionMode = false
+		m.syncListContent()
+		return m, nil
+	case "up", "k":
+		if m.actionIdx > 0 {
+			m.actionIdx--
+		}
+		m.syncListContent()
+		return m, nil
+	case "down", "j":
+		if m.actionIdx < len(m.itemActions)-1 {
+			m.actionIdx++
+		}
+		m.syncListContent()
+		return m, nil
+	case "enter":
+		if m.listIdx < 0 || m.listIdx >= len(m.items) || m.actionIdx >= len(m.itemActions) {
+			return m, nil
+		}
+		act := m.itemActions[m.actionIdx]
+		item := m.items[m.listIdx]
+		m.actionMode = false
+		if act.ID == model.ActionView {
+			return m, m.loadPreviewCmd()
+		}
+		m.loading = true
+		return m, m.executeActionCmd(act.ID, item)
+	}
+	return m, nil
+}
+
 func (m *Model) layoutViewports() {
-	_, _, prevW := LayoutWidths(m.width)
+	menuW, listW, prevW := LayoutWidths(m.width)
 	h := m.height - 4
 	if h < 4 {
 		h = 4
 	}
-	m.preview.Width = prevW - 2
-	m.preview.Height = h
-	m.renderPreview()
-}
-
-func (m *Model) renderPreview() {
-	_, _, prevW := LayoutWidths(m.width)
-	text, err := preview.RenderMarkdown(m.previewMD, prevW-4)
-	if err != nil {
-		text = m.previewMD
-	}
-	m.preview.SetContent(text)
-}
-
-func (m *Model) renderMenu(w int) string {
-	var b strings.Builder
-	b.WriteString("Modules\n\n")
-	for i := 0; i < m.menu.VisibleCount(); i++ {
-		label, depth := m.menu.LabelAt(i)
-		prefix := strings.Repeat("  ", depth)
-		line := prefix + label
-		if m.menu.IsExpandable(i) {
-			if m.menu.IsExpanded(i) {
-				line = prefix + "▾ " + label
-			} else {
-				line = prefix + "▸ " + label
-			}
+	inner := func(w int) int {
+		if w > 4 {
+			return w - 2
 		}
-		if i == m.menu.Cursor() && m.focus == model.FocusMenu {
+		return w
+	}
+	m.menuVP = viewport.New(inner(menuW), h)
+	m.listVP = viewport.New(inner(listW), h)
+	m.previewVP = viewport.New(inner(prevW), h)
+}
+
+func (m *Model) syncAllContent() {
+	m.syncMenuContent()
+	m.syncListContent()
+	m.syncPreviewContent()
+}
+
+func (m *Model) syncMenuContent() {
+	var b strings.Builder
+	b.WriteString("Navigation\n\n")
+	for i := 0; i < m.nav.VisibleCount(); i++ {
+		n, _ := m.nav.NodeAtVisible(i)
+		depth := m.nav.DepthAtVisible(i)
+		prefix := strings.Repeat("  ", depth)
+		line := prefix + n.Label
+		if m.nav.IsExpandable(i) {
+			if m.nav.IsExpanded(i) {
+				line = prefix + "▾ " + n.Label
+			} else {
+				line = prefix + "▸ " + n.Label
+			}
+		} else if n.List != nil {
+			line = prefix + "• " + n.Label
+		}
+		if i == m.nav.Cursor() && m.focus == model.FocusMenu {
 			line = "> " + line
 		} else {
 			line = "  " + line
 		}
-		if len(line) > w-1 {
-			line = line[:w-2] + "…"
-		}
 		b.WriteString(line + "\n")
 	}
-	return b.String()
+	m.menuVP.SetContent(b.String())
+	syncVPToLine(&m.menuVP, m.nav.Cursor()+2)
 }
 
-func (m *Model) renderList(w int) string {
-	title := string(m.subject)
-	if title == "" {
-		title = "Items"
-	}
+func (m *Model) syncListContent() {
 	var b strings.Builder
-	fmt.Fprintf(&b, "%s (%d)\n\n", title, len(m.items))
-	for i, it := range m.items {
-		mark := "[ ]"
-		if it.Selected {
-			mark = "[x]"
+	if !m.hasList {
+		b.WriteString("List\n\n")
+		b.WriteString("Select a leaf node in the tree\n")
+		b.WriteString("(marked with •) and press Enter.\n")
+	} else {
+		fmt.Fprintf(&b, "%s (%d)\n\n", m.listSpec.Subject, len(m.items))
+		if m.actionMode {
+			item := m.items[m.listIdx]
+			fmt.Fprintf(&b, "Actions for: %s\n\n", item.Title)
+			for i, act := range m.itemActions {
+				cursor := "  "
+				if i == m.actionIdx {
+					cursor = "> "
+				}
+				label := act.Label
+				if act.Danger {
+					label = "⚠ " + label
+				}
+				fmt.Fprintf(&b, "%s%s\n", cursor, label)
+			}
+			b.WriteString("\nEnter: run · Esc: cancel\n")
+		} else {
+			for i, it := range m.items {
+				mark := "[ ]"
+				if it.Selected {
+					mark = "[x]"
+				}
+				cursor := "  "
+				if i == m.listIdx && m.focus == model.FocusList {
+					cursor = "> "
+				}
+				line := fmt.Sprintf("%s%s %s", cursor, mark, it.Title)
+				if it.Subtitle != "" {
+					line += " — " + it.Subtitle
+				}
+				b.WriteString(line + "\n")
+			}
+			if len(m.items) == 0 && !m.loading {
+				b.WriteString("(empty)\n")
+			}
+			b.WriteString("\nEnter/a: actions · Space: select\n")
 		}
-		cursor := "  "
-		if i == m.listIdx && m.focus == model.FocusList {
-			cursor = "> "
-		}
-		line := fmt.Sprintf("%s%s %s", cursor, mark, it.Title)
-		if it.Subtitle != "" {
-			line += " — " + it.Subtitle
-		}
-		if len(line) > w-1 {
-			line = line[:w-2] + "…"
-		}
-		b.WriteString(line + "\n")
 	}
-	if len(m.items) == 0 && !m.loading {
-		b.WriteString("(empty)\n")
+	m.listVP.SetContent(b.String())
+	line := m.listIdx + 3
+	if m.actionMode {
+		line = m.actionIdx + 4
+	}
+	syncVPToLine(&m.listVP, line)
+}
+
+func (m *Model) syncPreviewContent() {
+	menuW, listW, prevW := LayoutWidths(m.width)
+	_ = menuW
+	_ = listW
+	w := prevW - 4
+	if w < 20 {
+		w = 20
+	}
+	text, err := preview.RenderMarkdown(m.previewMD, w)
+	if err != nil {
+		text = m.previewMD
+	}
+	m.previewVP.SetContent(text)
+}
+
+func syncVPToLine(vp *viewport.Model, line int) {
+	if line < 0 {
+		line = 0
+	}
+	if line < vp.YOffset {
+		vp.YOffset = line
+	} else if line >= vp.YOffset+vp.Height {
+		vp.YOffset = line - vp.Height + 1
+	}
+	if vp.YOffset < 0 {
+		vp.YOffset = 0
 	}
-	return b.String()
 }
 
 func (m *Model) moveUp() {
 	switch m.focus {
 	case model.FocusMenu:
-		m.menu.MoveUp()
+		m.nav.MoveUp()
 	case model.FocusList:
-		if m.listIdx > 0 {
+		if m.hasList && !m.actionMode && m.listIdx > 0 {
 			m.listIdx--
 		}
 	case model.FocusPreview:
-		m.preview.LineUp(1)
+		m.previewVP.LineUp(1)
 	}
 }
 
 func (m *Model) moveDown() {
 	switch m.focus {
 	case model.FocusMenu:
-		m.menu.MoveDown()
+		m.nav.MoveDown()
 	case model.FocusList:
-		if m.listIdx < len(m.items)-1 {
+		if m.hasList && !m.actionMode && m.listIdx < len(m.items)-1 {
 			m.listIdx++
 		}
 	case model.FocusPreview:
-		m.preview.LineDown(1)
+		m.previewVP.LineDown(1)
 	}
 }
 
-func (m *Model) loadListCmd(subject model.Subject) tea.Cmd {
+func (m *Model) loadListCmd(spec model.ListSpec) tea.Cmd {
 	return func() tea.Msg {
 		ctx := context.Background()
-		items, err := m.loader.List(ctx, subject)
-		return listLoadedMsg{items: items, subject: subject, err: err}
+		items, err := m.loader.List(ctx, spec)
+		return listLoadedMsg{items: items, spec: spec, err: err}
 	}
 }
 
@@ -304,17 +492,20 @@ func (m *Model) loadPreviewCmd() tea.Cmd {
 	}
 }
 
-func (m *Model) openVexCmd() tea.Cmd {
-	if m.listIdx < 0 || m.listIdx >= len(m.items) {
-		return nil
+func (m *Model) executeActionCmd(action model.ActionID, item model.Item) tea.Cmd {
+	return func() tea.Msg {
+		ctx := context.Background()
+		msg, err := m.loader.Execute(ctx, action, item, "")
+		return actionDoneMsg{message: msg, err: err}
 	}
-	item := m.items[m.listIdx]
-	if item.Kind != model.KindFile {
-		return func() tea.Msg {
-			return previewLoadedMsg{text: "_Press v on a spreadsheet file row._\n"}
-		}
+}
+
+func (m *Model) loadNavProjectsCmd() tea.Cmd {
+	return func() tea.Msg {
+		ctx := context.Background()
+		projects, err := m.loader.LoadProjectsForNav(ctx)
+		return navProjectsMsg{projects: projects, err: err}
 	}
-	return nil
 }
 
 func paneStyle(focused bool) lipgloss.Style {
@@ -326,14 +517,5 @@ func paneStyle(focused bool) lipgloss.Style {
 }
 
 func helpText() string {
-	return "Tab: pane | j/k: move | Space: select | Enter: preview | r: refresh | v: vex | q: quit"
-}
-
-// OpenVex launches the vex-tui binary for a file path when available.
-func OpenVex(path string) error {
-	if _, err := exec.LookPath("vex"); err != nil {
-		return fmt.Errorf("vex not found on PATH")
-	}
-	cmd := exec.Command("vex", path)
-	return cmd.Run()
+	return "Tab/Shift+Tab: pane · ↑↓/jk: scroll · Enter: open leaf/actions · Space: select · a: actions · r: refresh · q: quit"
 }
diff --git a/cmd/office/ui/app_test.go b/cmd/office/ui/app_test.go
index 97cf51c..6edb539 100644
--- a/cmd/office/ui/app_test.go
+++ b/cmd/office/ui/app_test.go
@@ -13,14 +13,11 @@ func TestKeyActionMenuDown(t *testing.T) {
 	}
 }
 
-func TestKeyActionListToggleSelect(t *testing.T) {
-	if got := ui.KeyAction(" ", model.FocusList); got != ui.ActionToggleSelect {
+func TestKeyActionShiftTabPrevPane(t *testing.T) {
+	if got := ui.KeyAction("shift+tab", model.FocusList); got != ui.ActionPrevPane {
 		t.Fatalf("got %v", got)
 	}
-}
-
-func TestKeyActionPreviewNoOp(t *testing.T) {
-	if got := ui.KeyAction(" ", model.FocusPreview); got != ui.ActionNone {
+	if got := ui.KeyAction("backtab", model.FocusPreview); got != ui.ActionPrevPane {
 		t.Fatalf("got %v", got)
 	}
 }
@@ -31,12 +28,15 @@ func TestKeyActionTabNextPane(t *testing.T) {
 	}
 }
 
+func TestKeyActionOpenActions(t *testing.T) {
+	if got := ui.KeyAction("a", model.FocusList); got != ui.ActionOpenActions {
+		t.Fatalf("got %v", got)
+	}
+}
+
 func TestLayoutWidths(t *testing.T) {
 	menu, list, preview := ui.LayoutWidths(120)
 	if menu+list+preview > 120 {
 		t.Fatalf("widths exceed total: %d+%d+%d", menu, list, preview)
 	}
-	if menu < 20 || list < 30 || preview < 30 {
-		t.Fatalf("widths too narrow: %d %d %d", menu, list, preview)
-	}
 }
diff --git a/cmd/office/ui/keys.go b/cmd/office/ui/keys.go
index 2a9d857..a69b9aa 100644
--- a/cmd/office/ui/keys.go
+++ b/cmd/office/ui/keys.go
@@ -11,7 +11,9 @@ const (
 	ActionMoveDown
 	ActionToggleSelect
 	ActionOpenPreview
+	ActionOpenActions
 	ActionNextPane
+	ActionPrevPane
 	ActionRefresh
 	ActionQuit
 	ActionOpenVex
@@ -24,6 +26,8 @@ func KeyAction(key string, pane model.FocusPane) Action {
 		return ActionQuit
 	case "tab":
 		return ActionNextPane
+	case "shift+tab", "backtab":
+		return ActionPrevPane
 	case "r":
 		return ActionRefresh
 	case "up", "k":
@@ -34,6 +38,10 @@ func KeyAction(key string, pane model.FocusPane) Action {
 		if pane == model.FocusList {
 			return ActionToggleSelect
 		}
+	case "a":
+		if pane == model.FocusList {
+			return ActionOpenActions
+		}
 	case "enter":
 		if pane == model.FocusList {
 			return ActionOpenPreview