diff --git a/CLAUDE.md b/CLAUDE.md
index ba9f63cbb..2888dd1c8 100644
--- a/CLAUDE.md
+++ b/CLAUDE.md
@@ -179,12 +179,31 @@ No custom diffing engines unless unavoidable.
 
 ## Keyboard Shortcuts
 
-Implemented using **native command handling**:
-
-* `Cmd + Enter` → Execute query
-* `Cmd + S` → Commit changes
-* `Cmd + R` → Refresh data
-* `Ctrl + Space` → Trigger autocomplete
+All keyboard shortcuts are centralized in `Core/KeyboardShortcuts.swift` following macOS Human Interface Guidelines.
+
+### Key Files
+* `Core/KeyboardShortcuts.swift` - Centralized shortcut definitions and key codes
+* `OpenTableApp.swift` - Menu command handlers using KeyboardShortcuts enum
+
+### Standard macOS Shortcuts (following HIG):
+* `⌘N` → New connection
+* `⌘T` → New tab  
+* `⌘W` → Close tab
+* `⌘S` → Save changes
+* `⌘R` → Refresh data
+* `⌘Z` / `⌘⇧Z` → Undo / Redo
+* `⌘X` / `⌘C` / `⌘V` → Cut / Copy / Paste
+* `⌘A` → Select All
+* `⌘F` → Toggle filters
+* `Escape` → Clear selection
+
+### Application-Specific:
+* `⌘↩` → Execute query
+* `⌘I` → Add row
+* `⌘D` → Duplicate row
+* `⌘B` → Toggle table browser
+* `⌘⇧H` → Toggle history
+* `⌃Space` → Trigger autocomplete
 
 ## Summary Rule
 
diff --git a/OpenTable/ContentView.swift b/OpenTable/ContentView.swift
index ccc7de666..9341c25b7 100644
--- a/OpenTable/ContentView.swift
+++ b/OpenTable/ContentView.swift
@@ -291,8 +291,8 @@ struct ContentView: View {
     
     private func setupEscapeKeyMonitor() {
         escapeKeyMonitor = NSEvent.addLocalMonitorForEvents(matching: .keyDown) { event in
-            // Escape key code is 53
-            if event.keyCode == 53 {
+            // Escape key - standard macOS cancel/clear shortcut
+            if event.keyCode == KeyCodes.escape {
                 NotificationCenter.default.post(name: .clearSelection, object: nil)
                 // Return nil to consume the event, or return event to let it propagate
                 return nil
diff --git a/OpenTable/Core/KeyboardShortcuts.swift b/OpenTable/Core/KeyboardShortcuts.swift
new file mode 100644
index 000000000..abe5de4fb
--- /dev/null
+++ b/OpenTable/Core/KeyboardShortcuts.swift
@@ -0,0 +1,298 @@
+//
+//  KeyboardShortcuts.swift
+//  OpenTable
+//
+//  Centralized keyboard shortcut definitions following macOS Human Interface Guidelines.
+//  Reference: https://developer.apple.com/design/human-interface-guidelines/keyboards
+//
+//  This file serves as the single source of truth for all keyboard shortcuts in the app.
+//  When adding new shortcuts, check this file first to avoid conflicts.
+//
+
+import SwiftUI
+
+// MARK: - Keyboard Shortcut Definitions
+
+/// Centralized keyboard shortcut definitions following macOS conventions.
+///
+/// ## macOS Standard Shortcuts (System-defined, should not be overridden):
+/// - ⌘Q: Quit application
+/// - ⌘H: Hide application
+/// - ⌘,: Open Settings/Preferences
+/// - ⌘M: Minimize window
+/// - ⌘W: Close window/tab
+/// - ⌘N: New document/connection
+/// - ⌘O: Open document
+/// - ⌘S: Save
+/// - ⌘Z: Undo
+/// - ⌘⇧Z: Redo
+/// - ⌘X: Cut
+/// - ⌘C: Copy
+/// - ⌘V: Paste
+/// - ⌘A: Select All
+/// - ⌘F: Find
+///
+/// ## Application-Specific Shortcuts:
+/// These follow macOS conventions where similar functionality exists.
+enum KeyboardShortcuts {
+    
+    // MARK: - File Menu
+    
+    /// New Connection (⌘N)
+    /// Standard macOS shortcut for creating new items
+    static let newConnection = KeyboardShortcut("n", modifiers: .command)
+    
+    /// New Tab (⌘T)
+    /// Standard macOS shortcut for new tabs (Safari, Terminal, etc.)
+    static let newTab = KeyboardShortcut("t", modifiers: .command)
+    
+    /// Close Tab (⌘W)
+    /// Standard macOS shortcut for closing current tab/window
+    static let closeTab = KeyboardShortcut("w", modifiers: .command)
+    
+    /// Save Changes (⌘S)
+    /// Standard macOS shortcut for saving
+    static let saveChanges = KeyboardShortcut("s", modifiers: .command)
+    
+    /// Refresh (⌘R)
+    /// Standard shortcut for refresh (Safari, Finder, etc.)
+    static let refresh = KeyboardShortcut("r", modifiers: .command)
+    
+    // MARK: - Edit Menu
+    
+    /// Undo (⌘Z)
+    /// Standard macOS undo shortcut
+    static let undo = KeyboardShortcut("z", modifiers: .command)
+    
+    /// Redo (⌘⇧Z)
+    /// Standard macOS redo shortcut
+    static let redo = KeyboardShortcut("z", modifiers: [.command, .shift])
+    
+    /// Cut (⌘X)
+    /// Standard macOS cut shortcut
+    static let cut = KeyboardShortcut("x", modifiers: .command)
+    
+    /// Copy (⌘C)
+    /// Standard macOS copy shortcut
+    static let copy = KeyboardShortcut("c", modifiers: .command)
+    
+    /// Paste (⌘V)
+    /// Standard macOS paste shortcut
+    static let paste = KeyboardShortcut("v", modifiers: .command)
+    
+    /// Select All (⌘A)
+    /// Standard macOS select all shortcut
+    static let selectAll = KeyboardShortcut("a", modifiers: .command)
+    
+    /// Delete (⌘⌫)
+    /// Delete selected items - macOS uses Cmd+Delete for moving to Trash
+    static let delete = KeyboardShortcut(.delete, modifiers: .command)
+    
+    /// Clear Selection (Escape)
+    /// Standard macOS convention for canceling/clearing
+    static let clearSelection = KeyboardShortcut(.escape, modifiers: [])
+    
+    // MARK: - Row Operations (Edit Menu - Custom)
+    
+    /// Add Row (⌘I)
+    /// Insert new row - 'I' for Insert, follows database convention
+    static let addRow = KeyboardShortcut("i", modifiers: .command)
+    
+    /// Duplicate Row (⌘D)
+    /// Duplicate selected item - follows Finder/Keynote convention
+    static let duplicateRow = KeyboardShortcut("d", modifiers: .command)
+    
+    /// Truncate Table (⌥⌫)
+    /// Dangerous operation, uses Option modifier for extra confirmation
+    static let truncateTable = KeyboardShortcut(.delete, modifiers: .option)
+    
+    // MARK: - View Menu
+    
+    /// Toggle Table Browser/Sidebar (⌘B)
+    /// Similar to Safari's bookmarks sidebar toggle
+    static let toggleSidebar = KeyboardShortcut("b", modifiers: .command)
+    
+    /// Toggle Inspector (⌘⌥B)
+    /// Similar to Xcode's inspector toggle
+    static let toggleInspector = KeyboardShortcut("b", modifiers: [.command, .option])
+    
+    /// Toggle Filters (⌘F)
+    /// Standard find/filter shortcut
+    static let toggleFilters = KeyboardShortcut("f", modifiers: .command)
+    
+    /// Toggle History Panel (⌘⇧H)
+    /// History panel toggle - H for History
+    static let toggleHistory = KeyboardShortcut("h", modifiers: [.command, .shift])
+    
+    // MARK: - Query Editor
+    
+    /// Execute Query (⌘↩)
+    /// Standard shortcut for executing/running in many IDEs
+    static let executeQuery = KeyboardShortcut(.return, modifiers: .command)
+    
+    /// Format Query (⌘⇧L)
+    /// Format/beautify the SQL query
+    static let formatQuery = KeyboardShortcut("l", modifiers: [.command, .shift])
+    
+    /// Trigger Autocomplete (⌃Space)
+    /// Standard IDE autocomplete trigger
+    static let triggerAutocomplete = KeyboardShortcut(.space, modifiers: .control)
+    
+    // MARK: - Navigation
+    
+    /// Next Tab (⌘⇧])
+    /// Standard macOS tab navigation (Safari, Terminal)
+    static let nextTab = KeyboardShortcut("]", modifiers: [.command, .shift])
+    
+    /// Previous Tab (⌘⇧[)
+    /// Standard macOS tab navigation (Safari, Terminal)
+    static let previousTab = KeyboardShortcut("[", modifiers: [.command, .shift])
+    
+    // MARK: - Window
+    
+    /// Minimize (⌘M)
+    /// Standard macOS minimize - handled by system
+    static let minimize = KeyboardShortcut("m", modifiers: .command)
+    
+    /// Zoom/Full Screen (⌃⌘F)
+    /// Standard macOS full screen toggle
+    static let fullScreen = KeyboardShortcut("f", modifiers: [.control, .command])
+}
+
+// MARK: - Shortcut Documentation
+
+/// Documentation of all keyboard shortcuts for reference.
+/// This can be displayed in a help menu or settings panel.
+struct ShortcutDocumentation {
+    
+    struct ShortcutInfo {
+        let keys: String
+        let description: String
+        let category: String
+    }
+    
+    static let allShortcuts: [ShortcutInfo] = [
+        // File
+        ShortcutInfo(keys: "⌘N", description: "New Connection", category: "File"),
+        ShortcutInfo(keys: "⌘T", description: "New Tab", category: "File"),
+        ShortcutInfo(keys: "⌘W", description: "Close Tab", category: "File"),
+        ShortcutInfo(keys: "⌘S", description: "Save Changes", category: "File"),
+        ShortcutInfo(keys: "⌘R", description: "Refresh", category: "File"),
+        
+        // Edit
+        ShortcutInfo(keys: "⌘Z", description: "Undo", category: "Edit"),
+        ShortcutInfo(keys: "⌘⇧Z", description: "Redo", category: "Edit"),
+        ShortcutInfo(keys: "⌘X", description: "Cut", category: "Edit"),
+        ShortcutInfo(keys: "⌘C", description: "Copy", category: "Edit"),
+        ShortcutInfo(keys: "⌘V", description: "Paste", category: "Edit"),
+        ShortcutInfo(keys: "⌘A", description: "Select All", category: "Edit"),
+        ShortcutInfo(keys: "⌘⌫", description: "Delete", category: "Edit"),
+        ShortcutInfo(keys: "⌘I", description: "Add Row", category: "Edit"),
+        ShortcutInfo(keys: "⌘D", description: "Duplicate Row", category: "Edit"),
+        ShortcutInfo(keys: "⌥⌫", description: "Truncate Table", category: "Edit"),
+        ShortcutInfo(keys: "Escape", description: "Clear Selection", category: "Edit"),
+        
+        // View
+        ShortcutInfo(keys: "⌘B", description: "Toggle Table Browser", category: "View"),
+        ShortcutInfo(keys: "⌘⌥B", description: "Toggle Inspector", category: "View"),
+        ShortcutInfo(keys: "⌘F", description: "Toggle Filters", category: "View"),
+        ShortcutInfo(keys: "⌘⇧H", description: "Toggle History", category: "View"),
+        
+        // Query
+        ShortcutInfo(keys: "⌘↩", description: "Execute Query", category: "Query"),
+        ShortcutInfo(keys: "⌘⇧L", description: "Format Query", category: "Query"),
+        ShortcutInfo(keys: "⌃Space", description: "Trigger Autocomplete", category: "Query"),
+        
+        // Navigation
+        ShortcutInfo(keys: "⌘⇧]", description: "Next Tab", category: "Navigation"),
+        ShortcutInfo(keys: "⌘⇧[", description: "Previous Tab", category: "Navigation"),
+        
+        // Data Grid
+        ShortcutInfo(keys: "↩", description: "Edit Cell", category: "Data Grid"),
+        ShortcutInfo(keys: "Tab", description: "Next Cell", category: "Data Grid"),
+        ShortcutInfo(keys: "⇧Tab", description: "Previous Cell", category: "Data Grid"),
+        ShortcutInfo(keys: "↑↓←→", description: "Navigate Cells", category: "Data Grid"),
+        ShortcutInfo(keys: "⇧↑↓", description: "Extend Selection", category: "Data Grid"),
+    ]
+}
+
+// MARK: - Key Code Constants
+
+/// AppKit key codes for use in NSEvent handling.
+/// These are used in performKeyEquivalent and keyDown handlers.
+enum KeyCodes {
+    // Letters
+    static let a: UInt16 = 0
+    static let b: UInt16 = 11
+    static let c: UInt16 = 8
+    static let d: UInt16 = 2
+    static let e: UInt16 = 14
+    static let f: UInt16 = 3
+    static let g: UInt16 = 5
+    static let h: UInt16 = 4
+    static let i: UInt16 = 34
+    static let j: UInt16 = 38
+    static let k: UInt16 = 40
+    static let l: UInt16 = 37
+    static let m: UInt16 = 46
+    static let n: UInt16 = 45
+    static let o: UInt16 = 31
+    static let p: UInt16 = 35
+    static let q: UInt16 = 12
+    static let r: UInt16 = 15
+    static let s: UInt16 = 1
+    static let t: UInt16 = 17
+    static let u: UInt16 = 32
+    static let v: UInt16 = 9
+    static let w: UInt16 = 13
+    static let x: UInt16 = 7
+    static let y: UInt16 = 16
+    static let z: UInt16 = 6
+    
+    // Numbers
+    static let zero: UInt16 = 29
+    static let one: UInt16 = 18
+    static let two: UInt16 = 19
+    static let three: UInt16 = 20
+    static let four: UInt16 = 21
+    static let five: UInt16 = 23
+    static let six: UInt16 = 22
+    static let seven: UInt16 = 26
+    static let eight: UInt16 = 28
+    static let nine: UInt16 = 25
+    
+    // Special Keys
+    static let returnKey: UInt16 = 36
+    static let tab: UInt16 = 48
+    static let space: UInt16 = 49
+    static let delete: UInt16 = 51  // Backspace
+    static let escape: UInt16 = 53
+    static let forwardDelete: UInt16 = 117
+    
+    // Arrow Keys
+    static let leftArrow: UInt16 = 123
+    static let rightArrow: UInt16 = 124
+    static let downArrow: UInt16 = 125
+    static let upArrow: UInt16 = 126
+    
+    // Function Keys
+    static let f1: UInt16 = 122
+    static let f2: UInt16 = 120
+    static let f3: UInt16 = 99
+    static let f4: UInt16 = 118
+    static let f5: UInt16 = 96
+    static let f6: UInt16 = 97
+    static let f7: UInt16 = 98
+    static let f8: UInt16 = 100
+    static let f9: UInt16 = 101
+    static let f10: UInt16 = 109
+    static let f11: UInt16 = 103
+    static let f12: UInt16 = 111
+    
+    // Brackets
+    static let leftBracket: UInt16 = 33   // [
+    static let rightBracket: UInt16 = 30  // ]
+    
+    // Keypad Enter (different from Return)
+    static let keypadEnter: UInt16 = 76
+}
diff --git a/OpenTable/Extensions/NSViewController+SwiftUI.swift b/OpenTable/Extensions/NSViewController+SwiftUI.swift
index 15bd6aa71..1578ef742 100644
--- a/OpenTable/Extensions/NSViewController+SwiftUI.swift
+++ b/OpenTable/Extensions/NSViewController+SwiftUI.swift
@@ -30,8 +30,8 @@ private class KeyboardHandlingHostingController<Content: View>: NSHostingControl
         // Check for Command modifier
         let commandPressed = event.modifierFlags.contains(.command)
         
-        // Handle Cmd+Return (Save)
-        if commandPressed && (event.keyCode == 36 || event.keyCode == 76) {
+        // Handle Cmd+Return (Save) - standard macOS convention
+        if commandPressed && (event.keyCode == KeyCodes.returnKey || event.keyCode == KeyCodes.keypadEnter) {
             onSave?()
             return true
         }
@@ -41,13 +41,13 @@ private class KeyboardHandlingHostingController<Content: View>: NSHostingControl
     }
     
     override func cancelOperation(_ sender: Any?) {
-        // Handle Escape key
+        // Handle Escape key - standard macOS cancel convention
         onCancel?()
     }
     
     override func keyDown(with event: NSEvent) {
         // Check for Escape key without modifiers
-        if event.keyCode == 53 && event.modifierFlags.intersection(.deviceIndependentFlagsMask).isEmpty {
+        if event.keyCode == KeyCodes.escape && event.modifierFlags.intersection(.deviceIndependentFlagsMask).isEmpty {
             onCancel?()
             return
         }
diff --git a/OpenTable/OpenTableApp.swift b/OpenTable/OpenTableApp.swift
index c9d53dea0..7bfc67255 100644
--- a/OpenTable/OpenTableApp.swift
+++ b/OpenTable/OpenTableApp.swift
@@ -2,6 +2,10 @@
 //  OpenTableApp.swift
 //  OpenTable
 //
+//  Main application entry point with menu commands.
+//  Keyboard shortcuts follow macOS Human Interface Guidelines.
+//  See KeyboardShortcuts.swift for centralized shortcut definitions.
+//
 //  Created by Ngo Quoc Dat on 16/12/25.
 //
 
@@ -17,6 +21,7 @@ final class AppState: ObservableObject {
     @Published var hasRowSelection: Bool = false  // True when rows are selected in data grid
     @Published var hasTableSelection: Bool = false  // True when tables are selected in sidebar
     @Published var isHistoryPanelVisible: Bool = false  // Global history panel visibility
+    @Published var isQueryTabActive: Bool = false  // True when current tab is a query tab
 }
 
 // MARK: - App
@@ -54,19 +59,19 @@ struct OpenTableApp: App {
         .windowStyle(.automatic)
         .defaultSize(width: 1200, height: 800)
         .commands {
-            // File menu
+            // MARK: - File Menu
             CommandGroup(replacing: .newItem) {
                 Button("New Connection...") {
                     NotificationCenter.default.post(name: .newConnection, object: nil)
                 }
-                .keyboardShortcut("n", modifiers: .command)
+                .keyboardShortcut(KeyboardShortcuts.newConnection)
             }
 
             CommandGroup(after: .newItem) {
                 Button("New Tab") {
                     NotificationCenter.default.post(name: .newTab, object: nil)
                 }
-                .keyboardShortcut("t", modifiers: .command)
+                .keyboardShortcut(KeyboardShortcuts.newTab)
                 .disabled(!appState.isConnected)
 
                 Divider()
@@ -74,7 +79,7 @@ struct OpenTableApp: App {
                 Button("Save Changes") {
                     NotificationCenter.default.post(name: .saveChanges, object: nil)
                 }
-                .keyboardShortcut("s", modifiers: .command)
+                .keyboardShortcut(KeyboardShortcuts.saveChanges)
                 .disabled(!appState.isConnected)
 
                 Button("Close Tab") {
@@ -89,36 +94,36 @@ struct OpenTableApp: App {
                         keyWindow?.close()
                     }
                 }
-                .keyboardShortcut("w", modifiers: .command)
+                .keyboardShortcut(KeyboardShortcuts.closeTab)
 
                 Divider()
 
                 Button("Refresh") {
                     NotificationCenter.default.post(name: .refreshData, object: nil)
                 }
-                .keyboardShortcut("r", modifiers: .command)
+                .keyboardShortcut(KeyboardShortcuts.refresh)
                 .disabled(!appState.isConnected)
             }
             
-            // Edit menu - Undo/Redo (replace the standard undo/redo)
+            // MARK: - Edit Menu - Undo/Redo
             CommandGroup(replacing: .undoRedo) {
                 Button("Undo") {
                     NotificationCenter.default.post(name: .undoChange, object: nil)
                 }
-                .keyboardShortcut("z", modifiers: .command)
+                .keyboardShortcut(KeyboardShortcuts.undo)
                 
                 Button("Redo") {
                     NotificationCenter.default.post(name: .redoChange, object: nil)
                 }
-                .keyboardShortcut("z", modifiers: [.command, .shift])
+                .keyboardShortcut(KeyboardShortcuts.redo)
             }
             
-            // Edit menu - replace pasteboard to add our Delete with shortcut
+            // MARK: - Edit Menu - Pasteboard
             CommandGroup(replacing: .pasteboard) {
                 Button("Cut") {
                     NSApp.sendAction(#selector(NSText.cut(_:)), to: nil, from: nil)
                 }
-                .keyboardShortcut("x", modifiers: .command)
+                .keyboardShortcut(KeyboardShortcuts.cut)
                 
                 Button("Copy") {
                     if appState.hasRowSelection {
@@ -129,12 +134,12 @@ struct OpenTableApp: App {
                         NSApp.sendAction(#selector(NSText.copy(_:)), to: nil, from: nil)
                     }
                 }
-                .keyboardShortcut("c", modifiers: .command)
+                .keyboardShortcut(KeyboardShortcuts.copy)
                 
                 Button("Paste") {
                     NSApp.sendAction(#selector(NSText.paste(_:)), to: nil, from: nil)
                 }
-                .keyboardShortcut("v", modifiers: .command)
+                .keyboardShortcut(KeyboardShortcuts.paste)
                 
                 Button("Delete") {
                     // Check if first responder is the history panel's table view
@@ -153,7 +158,7 @@ struct OpenTableApp: App {
                     // For data grid and other views, use notification for batched undo
                     NotificationCenter.default.post(name: .deleteSelectedRows, object: nil)
                 }
-                .keyboardShortcut(.delete, modifiers: .command)
+                .keyboardShortcut(KeyboardShortcuts.delete)
                 .disabled(!appState.isCurrentTabEditable && !appState.hasTableSelection)
                 
                 Divider()
@@ -161,28 +166,28 @@ struct OpenTableApp: App {
                 Button("Select All") {
                     NSApp.sendAction(#selector(NSText.selectAll(_:)), to: nil, from: nil)
                 }
-                .keyboardShortcut("a", modifiers: .command)
+                .keyboardShortcut(KeyboardShortcuts.selectAll)
                 
                 Button("Clear Selection") {
                     NotificationCenter.default.post(name: .clearSelection, object: nil)
                 }
-                .keyboardShortcut(.escape, modifiers: [])
+                .keyboardShortcut(KeyboardShortcuts.clearSelection)
             }
             
-            // Edit menu - row operations (after pasteboard)
+            // MARK: - Edit Menu - Row Operations
             CommandGroup(after: .pasteboard) {
                 Divider()
                 
                 Button("Add Row") {
                     NotificationCenter.default.post(name: .addNewRow, object: nil)
                 }
-                .keyboardShortcut("i", modifiers: .command)
+                .keyboardShortcut(KeyboardShortcuts.addRow)
                 .disabled(!appState.isCurrentTabEditable)
 
                 Button("Duplicate Row") {
                     NotificationCenter.default.post(name: .duplicateRow, object: nil)
                 }
-                .keyboardShortcut("d", modifiers: .command)
+                .keyboardShortcut(KeyboardShortcuts.duplicateRow)
                 .disabled(!appState.isCurrentTabEditable)
 
                 Divider()
@@ -191,22 +196,22 @@ struct OpenTableApp: App {
                 Button("Truncate Table") {
                     NotificationCenter.default.post(name: .truncateTables, object: nil)
                 }
-                .keyboardShortcut(.delete, modifiers: .option)
+                .keyboardShortcut(KeyboardShortcuts.truncateTable)
                 .disabled(!appState.hasTableSelection)
             }
 
-            // View menu
+            // MARK: - View Menu
             CommandGroup(after: .sidebar) {
                 Button("Toggle Table Browser") {
                     NotificationCenter.default.post(name: .toggleTableBrowser, object: nil)
                 }
-                .keyboardShortcut("b", modifiers: .command)
+                .keyboardShortcut(KeyboardShortcuts.toggleSidebar)
                 .disabled(!appState.isConnected)
 
                 Button("Toggle Inspector") {
                     NotificationCenter.default.post(name: .toggleRightSidebar, object: nil)
                 }
-                .keyboardShortcut("b", modifiers: [.command, .option])
+                .keyboardShortcut(KeyboardShortcuts.toggleInspector)
                 .disabled(!appState.isConnected)
 
                 Divider()
@@ -214,13 +219,35 @@ struct OpenTableApp: App {
                 Button("Toggle Filters") {
                     NotificationCenter.default.post(name: .toggleFilterPanel, object: nil)
                 }
-                .keyboardShortcut("f", modifiers: .command)
+                .keyboardShortcut(KeyboardShortcuts.toggleFilters)
                 .disabled(!appState.isConnected)
                 
                 Button("Toggle History") {
                     NotificationCenter.default.post(name: .toggleHistoryPanel, object: nil)
                 }
-                .keyboardShortcut("h", modifiers: [.command, .shift])
+                .keyboardShortcut(KeyboardShortcuts.toggleHistory)
+                .disabled(!appState.isConnected)
+            }
+            
+            // MARK: - Query Menu (Custom)
+            CommandMenu("Query") {
+                Button("Execute Query") {
+                    NotificationCenter.default.post(name: .executeQuery, object: nil)
+                }
+                .keyboardShortcut(KeyboardShortcuts.executeQuery)
+                .disabled(!appState.isConnected)
+                
+                Button("Format Query") {
+                    NotificationCenter.default.post(name: .formatQuery, object: nil)
+                }
+                .keyboardShortcut(KeyboardShortcuts.formatQuery)
+                .disabled(!appState.isConnected)
+                
+                Divider()
+                
+                Button("Clear Query") {
+                    NotificationCenter.default.post(name: .clearQuery, object: nil)
+                }
                 .disabled(!appState.isConnected)
             }
         }
diff --git a/OpenTable/Views/Editor/EditorTextView.swift b/OpenTable/Views/Editor/EditorTextView.swift
index a5ec6327e..7cca0a25e 100644
--- a/OpenTable/Views/Editor/EditorTextView.swift
+++ b/OpenTable/Views/Editor/EditorTextView.swift
@@ -194,14 +194,14 @@ final class EditorTextView: NSTextView {
             return
         }
         
-        // Cmd+Enter to execute query
-        if event.modifierFlags.contains(.command) && event.keyCode == 36 {
+        // Cmd+Enter to execute query (⌘↩)
+        if event.modifierFlags.contains(.command) && event.keyCode == KeyCodes.returnKey {
             onExecute?()
             return
         }
         
-        // Ctrl+Space to trigger manual completion
-        if event.modifierFlags.contains(.control) && event.keyCode == 49 {
+        // Ctrl+Space to trigger manual completion (⌃Space)
+        if event.modifierFlags.contains(.control) && event.keyCode == KeyCodes.space {
             onManualCompletion?()
             return
         }
@@ -234,7 +234,7 @@ final class EditorTextView: NSTextView {
         }
         
         // Handle backspace to delete matching pairs
-        if event.keyCode == 51 { // Backspace
+        if event.keyCode == KeyCodes.delete {
             if shouldDeletePair() {
                 deletePair()
                 return
diff --git a/OpenTable/Views/Editor/HistoryListViewController.swift b/OpenTable/Views/Editor/HistoryListViewController.swift
index 9d44a70be..33b156e01 100644
--- a/OpenTable/Views/Editor/HistoryListViewController.swift
+++ b/OpenTable/Views/Editor/HistoryListViewController.swift
@@ -1238,7 +1238,7 @@ private class HistoryTableView: NSTableView, NSMenuItemValidation {
         let modifiers = event.modifierFlags.intersection(.deviceIndependentFlagsMask)
         
         // Return/Enter key - open in new tab
-        if (event.keyCode == 36 || event.keyCode == 76) && modifiers.isEmpty {
+        if (event.keyCode == KeyCodes.returnKey || event.keyCode == KeyCodes.keypadEnter) && modifiers.isEmpty {
             if selectedRow >= 0 {
                 keyboardDelegate?.handleReturnKey()
                 return
@@ -1246,7 +1246,7 @@ private class HistoryTableView: NSTableView, NSMenuItemValidation {
         }
         
         // Space key - toggle preview
-        if event.keyCode == 49 && modifiers.isEmpty {
+        if event.keyCode == KeyCodes.space && modifiers.isEmpty {
             if selectedRow >= 0 {
                 keyboardDelegate?.handleSpaceKey()
                 return
@@ -1254,19 +1254,19 @@ private class HistoryTableView: NSTableView, NSMenuItemValidation {
         }
         
         // Cmd+E - edit bookmark
-        if event.keyCode == 14 && modifiers == .command {
+        if event.keyCode == KeyCodes.e && modifiers == .command {
             keyboardDelegate?.handleEditBookmark()
             return
         }
         
         // Escape key - clear search or selection
-        if event.keyCode == 53 && modifiers.isEmpty {
+        if event.keyCode == KeyCodes.escape && modifiers.isEmpty {
             keyboardDelegate?.handleEscapeKey()
             return
         }
         
         // Delete key (bare, not Cmd+Delete which goes through menu)
-        if event.keyCode == 51 && modifiers.isEmpty {
+        if event.keyCode == KeyCodes.delete && modifiers.isEmpty {
             if selectedRow >= 0 {
                 keyboardDelegate?.handleDeleteKey()
                 return
diff --git a/OpenTable/Views/Editor/QueryEditorView.swift b/OpenTable/Views/Editor/QueryEditorView.swift
index d27647de1..89b85246e 100644
--- a/OpenTable/Views/Editor/QueryEditorView.swift
+++ b/OpenTable/Views/Editor/QueryEditorView.swift
@@ -45,15 +45,14 @@ struct QueryEditorView: View {
                 Image(systemName: "trash")
             }
             .buttonStyle(.borderless)
-            .help("Clear Query (⌘+Delete)")
-            .keyboardShortcut(.delete, modifiers: .command)
+            .help("Clear Query")
             
             // Format button
             Button(action: formatQuery) {
                 Image(systemName: "text.alignleft")
             }
             .buttonStyle(.borderless)
-            .help("Format Query")
+            .help("Format Query (⌘⇧L)")
             
             Divider()
                 .frame(height: 16)
@@ -67,7 +66,7 @@ struct QueryEditorView: View {
             }
             .buttonStyle(.borderedProminent)
             .controlSize(.small)
-            .keyboardShortcut(.return, modifiers: .command)
+            .keyboardShortcut(KeyboardShortcuts.executeQuery)
         }
         .padding(.horizontal, 12)
         .padding(.vertical, 8)
diff --git a/OpenTable/Views/Editor/QueryTabBar.swift b/OpenTable/Views/Editor/QueryTabBar.swift
index 3f260317f..a3351944f 100644
--- a/OpenTable/Views/Editor/QueryTabBar.swift
+++ b/OpenTable/Views/Editor/QueryTabBar.swift
@@ -41,8 +41,8 @@ struct QueryTabBar: View {
                     .frame(width: 28, height: 28)
             }
             .buttonStyle(.borderless)
-            .help("New Query Tab (⌘+T)")
-            .keyboardShortcut("t", modifiers: .command)
+            .help("New Query Tab (⌘T)")
+            .keyboardShortcut(KeyboardShortcuts.newTab)
             .padding(.trailing, 8)
         }
         .frame(height: 32)
diff --git a/OpenTable/Views/Editor/SQLCompletionWindowController.swift b/OpenTable/Views/Editor/SQLCompletionWindowController.swift
index 0a5285a92..bdfa85629 100644
--- a/OpenTable/Views/Editor/SQLCompletionWindowController.swift
+++ b/OpenTable/Views/Editor/SQLCompletionWindowController.swift
@@ -168,23 +168,23 @@ final class SQLCompletionWindowController: NSObject {
         guard isVisible else { return false }
         
         switch event.keyCode {
-        case 125: // Down arrow
+        case KeyCodes.downArrow: // Down arrow
             selectNext()
             return true
             
-        case 126: // Up arrow
+        case KeyCodes.upArrow: // Up arrow
             selectPrevious()
             return true
             
-        case 36: // Return
+        case KeyCodes.returnKey: // Return
             confirmSelection()
             return true
             
-        case 53: // Escape
+        case KeyCodes.escape: // Escape
             dismiss()
             return true
             
-        case 48: // Tab
+        case KeyCodes.tab: // Tab
             confirmSelection()
             return true
             
diff --git a/OpenTable/Views/Results/DataGridView.swift b/OpenTable/Views/Results/DataGridView.swift
index df7e9417d..3e7ec08ba 100644
--- a/OpenTable/Views/Results/DataGridView.swift
+++ b/OpenTable/Views/Results/DataGridView.swift
@@ -1441,8 +1441,8 @@ final class KeyHandlingTableView: NSTableView, NSMenuItemValidation {
     
     /// Override to catch Delete/Backspace before menu items can intercept
     override func performKeyEquivalent(with event: NSEvent) -> Bool {
-        // Delete (keyCode 51) or Forward Delete (keyCode 117)
-        if event.keyCode == 51 || event.keyCode == 117 {
+        // Delete (Backspace) or Forward Delete
+        if event.keyCode == KeyCodes.delete || event.keyCode == KeyCodes.forwardDelete {
             let selectedIndices = Set(selectedRowIndexes.map { $0 })
             if !selectedIndices.isEmpty && coordinator?.isEditable == true {
                 // Mark rows for deletion
@@ -1457,21 +1457,21 @@ final class KeyHandlingTableView: NSTableView, NSMenuItemValidation {
 
     override func keyDown(with event: NSEvent) {
         // Note: Cmd+N is captured by app menu (New Connection)
-        // Use File > Add Row (Cmd+I) for adding rows
+        // Use Edit > Add Row (Cmd+I) for adding rows
 
         let row = selectedRow
         let isShiftHeld = event.modifierFlags.contains(.shift)
 
         switch event.keyCode {
-        case 126: // Up arrow - move to previous row (Shift extends selection)
+        case KeyCodes.upArrow: // Up arrow - move to previous row (Shift extends selection)
             handleUpArrow(currentRow: row, isShiftHeld: isShiftHeld)
             return
 
-        case 125: // Down arrow - move to next row (Shift extends selection)
+        case KeyCodes.downArrow: // Down arrow - move to next row (Shift extends selection)
             handleDownArrow(currentRow: row, isShiftHeld: isShiftHeld)
             return
 
-        case 123: // Left arrow - move to previous column
+        case KeyCodes.leftArrow: // Left arrow - move to previous column
             if focusedColumn > 1 { // Skip row number column (index 0)
                 focusedColumn -= 1
                 if row >= 0 {
@@ -1486,7 +1486,7 @@ final class KeyHandlingTableView: NSTableView, NSMenuItemValidation {
             }
             return
 
-        case 124: // Right arrow - move to next column
+        case KeyCodes.rightArrow: // Right arrow - move to next column
             if focusedColumn >= 1 && focusedColumn < numberOfColumns - 1 {
                 focusedColumn += 1
                 if row >= 0 {
@@ -1501,19 +1501,19 @@ final class KeyHandlingTableView: NSTableView, NSMenuItemValidation {
             }
             return
 
-        case 36: // Enter/Return - edit focused cell
+        case KeyCodes.returnKey: // Enter/Return - edit focused cell
             if row >= 0 && focusedColumn >= 1 && coordinator?.isEditable == true {
                 editColumn(focusedColumn, row: row, with: nil, select: true)
             }
             return
 
-        case 53: // Escape - clear focus and selection
+        case KeyCodes.escape: // Escape - clear focus and selection
             focusedRow = -1
             focusedColumn = -1
             NotificationCenter.default.post(name: .clearSelection, object: nil)
             return
 
-        case 51, 117: // Delete or Backspace key
+        case KeyCodes.delete, KeyCodes.forwardDelete: // Delete or Backspace key
             // Post notification to trigger batched deletion in MainContentView
             // This enables undoing all deletions at once
             if !selectedRowIndexes.isEmpty {
@@ -1521,7 +1521,7 @@ final class KeyHandlingTableView: NSTableView, NSMenuItemValidation {
                 return
             }
 
-        case 48: // Tab - move to next cell
+        case KeyCodes.tab: // Tab - move to next cell
             if row >= 0 && focusedColumn >= 1 {
                 var nextColumn = focusedColumn + 1
                 var nextRow = row
diff --git a/OpenTable/Views/Sidebar/SidebarView.swift b/OpenTable/Views/Sidebar/SidebarView.swift
index 55e7b8ef0..8d88b3823 100644
--- a/OpenTable/Views/Sidebar/SidebarView.swift
+++ b/OpenTable/Views/Sidebar/SidebarView.swift
@@ -240,19 +240,19 @@ struct SidebarView: View {
             NSPasteboard.general.clearContents()
             NSPasteboard.general.setString(names.joined(separator: ","), forType: .string)
         }
-        .keyboardShortcut("c", modifiers: .command)
+        .keyboardShortcut(KeyboardShortcuts.copy)
 
         Divider()
 
         Button("Truncate") {
             batchToggleTruncate()
         }
-        .keyboardShortcut(.delete, modifiers: .option)
+        .keyboardShortcut(KeyboardShortcuts.truncateTable)
 
         Button("Delete", role: .destructive) {
             batchToggleDelete()
         }
-        .keyboardShortcut(.delete, modifiers: .command)
+        .keyboardShortcut(KeyboardShortcuts.delete)
     }
     
     /// Batch toggle truncate for all selected tables
diff --git a/README.md b/README.md
index 090a4c8fb..6f43b3f57 100644
--- a/README.md
+++ b/README.md
@@ -66,16 +66,55 @@ A native macOS database client built with SwiftUI. A fast, lightweight alternati
 
 ## Keyboard Shortcuts
 
+All keyboard shortcuts follow macOS Human Interface Guidelines for consistency with native apps.
+
+### File Menu
+| Shortcut | Action |
+|----------|--------|
+| `⌘N` | New connection |
+| `⌘T` | New tab |
+| `⌘W` | Close tab |
+| `⌘S` | Save/commit changes |
+| `⌘R` | Refresh data |
+
+### Edit Menu
+| Shortcut | Action |
+|----------|--------|
+| `⌘Z` | Undo |
+| `⌘⇧Z` | Redo |
+| `⌘X` | Cut |
+| `⌘C` | Copy |
+| `⌘V` | Paste |
+| `⌘A` | Select All |
+| `⌘⌫` | Delete |
+| `⌘I` | Add row |
+| `⌘D` | Duplicate row |
+| `⌥⌫` | Truncate table |
+| `Escape` | Clear selection |
+
+### View Menu
+| Shortcut | Action |
+|----------|--------|
+| `⌘B` | Toggle table browser |
+| `⌘⌥B` | Toggle inspector |
+| `⌘F` | Toggle filters |
+| `⌘⇧H` | Toggle history |
+
+### Query Menu
+| Shortcut | Action |
+|----------|--------|
+| `⌘↩` | Execute query |
+| `⌘⇧L` | Format query |
+| `⌃Space` | Trigger autocomplete |
+
+### Data Grid Navigation
 | Shortcut | Action |
 |----------|--------|
-| `Cmd+Enter` | Execute query |
-| `Cmd+S` | Save/commit changes |
-| `Cmd+R` | Refresh data |
-| `Cmd+W` | Close tab |
-| `Cmd+N` | New connection |
-| `Cmd+E` | Export to CSV |
-| `Cmd+Shift+E` | Export to JSON |
-| `Ctrl+Space` | Trigger autocomplete |
+| `↩` | Edit cell |
+| `Tab` | Next cell |
+| `⇧Tab` | Previous cell |
+| `↑↓←→` | Navigate cells |
+| `⇧↑↓` | Extend selection |
 
 ## Requirements