feat(window): multi-window support with a native Window menu

README.md

@@ -32,10 +32,11 @@ A native macOS Markdown viewer built with [Tauri v2](https://v2.tauri.app/). Bro
 - **Relative link navigation** — Click `.md` links to navigate between documents
 - **Dark mode** — Follows macOS system appearance, toggleable manually
 - **Session persistence** — Remembers your last opened folder across launches
+- **Multiple windows** — Open a second folder side by side in its own window (Cmd+N for an empty window, Shift+Cmd+N to pick a folder). Each window keeps its own document, outline and search
 - **Open single files** — Open `.md` files directly via CLI, Finder "Open With", or drag & drop
 - **PDF export** — Export the current document as PDF with native rendering
 - **CLI support** — Open a folder or file directly: `mdv ~/docs` or `mdv ~/docs/README.md`
-- **Native menu** — Cmd+O to open a folder, standard macOS app menu
+- **Native menu** — Cmd+O to open a file, Shift+Cmd+O for a folder, standard macOS app menu
 
 ### Markdown Rendering
 

docs/guide/features.md

@@ -8,6 +8,39 @@ Open any folder and navigate its directory tree via the sidebar. The sidebar sho
 
 A breadcrumb bar at the top shows your current location and lets you navigate back to parent directories.
 
+## Multiple Windows
+
+Two folders can be read side by side, each in its own window:
+
+- **File › New Window** (`Cmd+N`) opens an empty window on the welcome screen.
+- **File › Open Folder in New Window…** (`Shift+Cmd+N`) picks a folder and opens
+  it in a new window, leaving the current window untouched.
+
+The **Window** menu lists every open window and switches to the one you pick
+(the active one is checked). Each window is named after the document it shows —
+or its folder when no document is open yet — so the list stays readable.
+
+It also carries the usual macOS window commands:
+
+- **Minimize**, **Zoom**, **Enter Full Screen**
+- **Fill** — the window takes the whole screen minus menu bar and Dock
+- **Center** — keeps the size, centers the window on its screen
+- **Move & Resize** — halves (Left, Right, Top, Bottom), quarters, and **Return
+  to Previous Size**, which undoes a run of arrangements in one step
+- **Bring All to Front** — raises every window, keeping the active one in front
+
+These act on the frontmost window and use the screen it currently sits on. They
+have no keyboard shortcuts on purpose: macOS already binds Control-Option-arrows
+to its own window tiling, which keeps working alongside them.
+
+Windows are fully independent — document, outline, search state and scroll
+position are per window. Menu commands and their shortcuts (Find, Print, Export
+as PDF, Open Recent, Toggle Dark Mode…) act on the frontmost window only.
+The recent-files list is shared (the native "Open Recent" submenu is app-wide).
+Preferences (theme, fonts, language) are stored once for the app and applied
+when a window opens, so changing them updates the window you changed them in and
+every window opened afterwards.
+
 ## Markdown Rendering
 
 Full GitHub-Flavored Markdown (GFM) support including:

docs/reference/keyboard-shortcuts.md

@@ -4,9 +4,19 @@
 
 | Shortcut | Action |
 |---|---|
-| **Cmd+O** | Open folder |
+| **Cmd+O** | Open file |
+| **Shift+Cmd+O** | Open folder |
+| **Cmd+N** | New window (welcome screen) |
+| **Shift+Cmd+N** | Open a folder in a new window |
+| **Cmd+M** | Minimize the current window |
+| **Cmd+W** | Close the current window |
 | **Cmd+Q** | Quit application |
 
+Windows are independent: each one keeps its own document, outline, search and
+scroll position. Menu commands (Find, Print, Export as PDF, Open Recent…) always
+apply to the frontmost window. The **Window** menu lists the open windows and
+switches to the one you select.
+
 ## Overlays
 
 | Shortcut | Action |

src-tauri/Cargo.toml

@@ -32,6 +32,7 @@ font-kit = "0.14"
 
 [target.'cfg(target_os = "macos")'.dependencies]
 objc2 = "0.6"
+objc2-app-kit = { version = "0.3", features = ["NSScreen"] }
 objc2-foundation = { version = "0.3", features = ["NSData", "NSError", "NSString"] }
 objc2-web-kit = { version = "0.3", features = ["WKWebView", "WKPDFConfiguration", "block2", "objc2-app-kit"] }
 block2 = "0.6"

src-tauri/capabilities/default.json

@@ -2,7 +2,7 @@
   "$schema": "../gen/schemas/desktop-schema.json",
   "identifier": "default",
   "description": "Default permissions for the app",
-  "windows": ["main"],
+  "windows": ["main", "viewer-*"],
   "permissions": [
     "core:default",
     "core:window:allow-start-dragging",