diff --git a/Info-macOS.plist b/Info-macOS.plist
index b720fb9..f53789e 100644
--- a/Info-macOS.plist
+++ b/Info-macOS.plist
@@ -21,11 +21,13 @@
 				<string>phtml</string>
 				<string>csv</string>
 				<string>tsv</string>
+				<string>txt</string>
 				<string>toml</string>
 				<string>ini</string>
 				<string>yaml</string>
 				<string>yml</string>
 				<string>xml</string>
+				<string>plist</string>
 				<string>sql</string>
 				<string>log</string>
 				<string>vim</string>
@@ -40,6 +42,9 @@
 				<string>psm1</string>
 				<string>html</string>
 				<string>htm</string>
+				<string>ee</string>
+				<string>exp</string>
+				<string>tmpl</string>
 				<string>css</string>
 				<string>c</string>
 				<string>cpp</string>
@@ -69,6 +74,13 @@
 				<string>conf</string>
 				<string>nginx</string>
 			</array>
+			<key>LSItemContentTypes</key>
+			<array>
+				<string>public.plain-text</string>
+				<string>public.text</string>
+				<string>public.source-code</string>
+				<string>net.daringfireball.markdown</string>
+			</array>
 			<key>CFBundleTypeName</key>
 			<string>Neon Vision Editor Document</string>
 			<key>CFBundleTypeRole</key>
diff --git a/Neon Vision Editor.xcodeproj/project.pbxproj b/Neon Vision Editor.xcodeproj/project.pbxproj
index 9c586ad..68a5dd5 100644
--- a/Neon Vision Editor.xcodeproj/project.pbxproj	
+++ b/Neon Vision Editor.xcodeproj/project.pbxproj	
@@ -358,7 +358,7 @@
 				CODE_SIGNING_ALLOWED = YES;
 				CODE_SIGN_IDENTITY = "Apple Development";
 				CODE_SIGN_STYLE = Automatic;
-				CURRENT_PROJECT_VERSION = 323;
+				CURRENT_PROJECT_VERSION = 324;
 				DEAD_CODE_STRIPPING = YES;
 				DEVELOPMENT_TEAM = CS727NF72U;
 				ENABLE_APP_SANDBOX = YES;
@@ -439,7 +439,7 @@
 				CODE_SIGNING_ALLOWED = YES;
 				CODE_SIGN_IDENTITY = "Apple Development";
 				CODE_SIGN_STYLE = Automatic;
-				CURRENT_PROJECT_VERSION = 323;
+				CURRENT_PROJECT_VERSION = 324;
 				DEAD_CODE_STRIPPING = YES;
 				DEVELOPMENT_TEAM = CS727NF72U;
 				ENABLE_APP_SANDBOX = YES;
diff --git a/Neon Vision Editor/Core/LanguageDetector.swift b/Neon Vision Editor/Core/LanguageDetector.swift
index 8e38492..f8dba80 100644
--- a/Neon Vision Editor/Core/LanguageDetector.swift	
+++ b/Neon Vision Editor/Core/LanguageDetector.swift	
@@ -22,6 +22,7 @@ public struct LanguageDetector {
         "phtml": "php",
         "csv": "csv",
         "tsv": "csv",
+        "txt": "plain",
         "toml": "toml",
         "ini": "ini",
         "yaml": "yaml",
@@ -126,15 +127,21 @@ public struct LanguageDetector {
         }
 
         // Extension/dotfile hint
+        var extensionHint: String?
         if let byURL = preferredLanguage(for: fileURL) {
+            extensionHint = byURL
             bump(byURL, 300)
         } else if let name {
             let lowerName = name.lowercased()
             if let mapped = dotfileMap[lowerName] {
+                extensionHint = mapped
                 bump(mapped, 300)
             } else {
                 let ext = URL(fileURLWithPath: lowerName).pathExtension.lowercased()
-                if let mapped = extensionMap[ext] { bump(mapped, 300) }
+                if let mapped = extensionMap[ext] {
+                    extensionHint = mapped
+                    bump(mapped, 300)
+                }
             }
         }
 
@@ -341,7 +348,11 @@ public struct LanguageDetector {
         let second = sorted.dropFirst().first ?? ("plain", 0)
         let confidence = max(0, top.value - second.value)
         let minScore = 10
-        let lang = top.value >= minScore ? top.key : "plain"
+        var lang = top.value >= minScore ? top.key : "plain"
+        // Keep explicit Markdown filenames stable even if body text contains SQL-like terms.
+        if extensionHint == "markdown" {
+            lang = "markdown"
+        }
         return Result(lang: lang, scores: scores, confidence: confidence)
     }
 
diff --git a/Neon Vision Editor/Data/EditorViewModel.swift b/Neon Vision Editor/Data/EditorViewModel.swift
index 4f9507b..d4c3698 100644
--- a/Neon Vision Editor/Data/EditorViewModel.swift	
+++ b/Neon Vision Editor/Data/EditorViewModel.swift	
@@ -383,6 +383,7 @@ class EditorViewModel: ObservableObject {
         "phtml": "php",
         "csv": "csv",
         "tsv": "csv",
+        "txt": "plain",
         "toml": "toml",
         "ini": "ini",
         "yaml": "yaml",
diff --git a/Neon Vision Editor/UI/ContentView.swift b/Neon Vision Editor/UI/ContentView.swift
index 5f25e79..a04c2f8 100644
--- a/Neon Vision Editor/UI/ContentView.swift	
+++ b/Neon Vision Editor/UI/ContentView.swift	
@@ -1686,6 +1686,9 @@ struct ContentView: View {
             persistUnsavedDraftSnapshotIfNeeded()
 #endif
         }
+        .onOpenURL { url in
+            viewModel.openFile(url: url)
+        }
 #if os(iOS)
         .onReceive(NotificationCenter.default.publisher(for: UIApplication.willResignActiveNotification)) { _ in
             persistSessionIfReady()
@@ -2014,32 +2017,141 @@ struct ContentView: View {
         UserDefaults.standard.set(viewModel.selectedTab?.fileURL?.absoluteString, forKey: "LastSessionSelectedFileURL")
 #if os(iOS)
         persistLastSessionSecurityScopedBookmarks(fileURLs: fileURLs, selectedURL: viewModel.selectedTab?.fileURL)
+#elseif os(macOS)
+        persistLastSessionSecurityScopedBookmarksMac(fileURLs: fileURLs, selectedURL: viewModel.selectedTab?.fileURL)
 #endif
     }
 
     private func restoredLastSessionFileURLs() -> [URL] {
-#if os(iOS)
+#if os(macOS)
+        let bookmarked = restoreSessionURLsFromSecurityScopedBookmarksMac()
+        if !bookmarked.isEmpty {
+            return bookmarked
+        }
+#elseif os(iOS)
         let bookmarked = restoreSessionURLsFromSecurityScopedBookmarks()
         if !bookmarked.isEmpty {
             return bookmarked
         }
 #endif
-        let paths = UserDefaults.standard.stringArray(forKey: "LastSessionFileURLs") ?? []
-        return paths.compactMap(URL.init(string:))
+        let stored = UserDefaults.standard.stringArray(forKey: "LastSessionFileURLs") ?? []
+        var urls: [URL] = []
+        var seen: Set<String> = []
+        for raw in stored {
+            guard let parsed = restoredSessionURL(from: raw) else { continue }
+            let standardized = parsed.standardizedFileURL
+            // Only restore files that still exist; avoids empty placeholder tabs on launch.
+            guard FileManager.default.fileExists(atPath: standardized.path) else { continue }
+            let key = standardized.absoluteString
+            if seen.insert(key).inserted {
+                urls.append(standardized)
+            }
+        }
+        return urls
     }
 
     private func restoredLastSessionSelectedFileURL() -> URL? {
-#if os(iOS)
+#if os(macOS)
+        if let bookmarked = restoreSelectedURLFromSecurityScopedBookmarkMac() {
+            return bookmarked
+        }
+#elseif os(iOS)
         if let bookmarked = restoreSelectedURLFromSecurityScopedBookmark() {
             return bookmarked
         }
 #endif
-        guard let selectedPath = UserDefaults.standard.string(forKey: "LastSessionSelectedFileURL") else {
+        guard let selectedPath = UserDefaults.standard.string(forKey: "LastSessionSelectedFileURL"),
+              let selectedURL = restoredSessionURL(from: selectedPath) else {
             return nil
         }
-        return URL(string: selectedPath)
+        let standardized = selectedURL.standardizedFileURL
+        return FileManager.default.fileExists(atPath: standardized.path) ? standardized : nil
     }
 
+    private func restoredSessionURL(from raw: String) -> URL? {
+        // Support both absolute URL strings ("file:///...") and legacy plain paths.
+        if let url = URL(string: raw), url.isFileURL {
+            return url
+        }
+        if raw.hasPrefix("/") {
+            return URL(fileURLWithPath: raw)
+        }
+        return nil
+    }
+
+#if os(macOS)
+    private var macLastSessionBookmarksKey: String { "MacLastSessionFileBookmarks" }
+    private var macLastSessionSelectedBookmarkKey: String { "MacLastSessionSelectedFileBookmark" }
+
+    private func persistLastSessionSecurityScopedBookmarksMac(fileURLs: [URL], selectedURL: URL?) {
+        let bookmarkData = fileURLs.compactMap { makeSecurityScopedBookmarkDataMac(for: $0) }
+        UserDefaults.standard.set(bookmarkData, forKey: macLastSessionBookmarksKey)
+        if let selectedURL, let selectedData = makeSecurityScopedBookmarkDataMac(for: selectedURL) {
+            UserDefaults.standard.set(selectedData, forKey: macLastSessionSelectedBookmarkKey)
+        } else {
+            UserDefaults.standard.removeObject(forKey: macLastSessionSelectedBookmarkKey)
+        }
+    }
+
+    private func restoreSessionURLsFromSecurityScopedBookmarksMac() -> [URL] {
+        guard let saved = UserDefaults.standard.array(forKey: macLastSessionBookmarksKey) as? [Data], !saved.isEmpty else {
+            return []
+        }
+        var urls: [URL] = []
+        var seen: Set<String> = []
+        for data in saved {
+            guard let url = resolveSecurityScopedBookmarkMac(data) else { continue }
+            let standardized = url.standardizedFileURL
+            guard FileManager.default.fileExists(atPath: standardized.path) else { continue }
+            let key = standardized.absoluteString
+            if seen.insert(key).inserted {
+                urls.append(standardized)
+            }
+        }
+        return urls
+    }
+
+    private func restoreSelectedURLFromSecurityScopedBookmarkMac() -> URL? {
+        guard let data = UserDefaults.standard.data(forKey: macLastSessionSelectedBookmarkKey),
+              let resolved = resolveSecurityScopedBookmarkMac(data) else {
+            return nil
+        }
+        let standardized = resolved.standardizedFileURL
+        return FileManager.default.fileExists(atPath: standardized.path) ? standardized : nil
+    }
+
+    private func makeSecurityScopedBookmarkDataMac(for url: URL) -> Data? {
+        let didStartScopedAccess = url.startAccessingSecurityScopedResource()
+        defer {
+            if didStartScopedAccess {
+                url.stopAccessingSecurityScopedResource()
+            }
+        }
+        do {
+            return try url.bookmarkData(
+                options: [.withSecurityScope],
+                includingResourceValuesForKeys: nil,
+                relativeTo: nil
+            )
+        } catch {
+            return nil
+        }
+    }
+
+    private func resolveSecurityScopedBookmarkMac(_ data: Data) -> URL? {
+        var isStale = false
+        guard let resolved = try? URL(
+            resolvingBookmarkData: data,
+            options: [.withSecurityScope, .withoutUI],
+            relativeTo: nil,
+            bookmarkDataIsStale: &isStale
+        ) else {
+            return nil
+        }
+        return resolved
+    }
+#endif
+
 #if os(iOS)
     private var unsavedDraftSnapshotKey: String { "IOSUnsavedDraftSnapshotV1" }
     private var lastSessionBookmarksKey: String { "LastSessionFileBookmarks" }
diff --git a/Neon Vision EditorTests/LanguageDetectorTests.swift b/Neon Vision EditorTests/LanguageDetectorTests.swift
index 51b5490..0763336 100644
--- a/Neon Vision EditorTests/LanguageDetectorTests.swift	
+++ b/Neon Vision EditorTests/LanguageDetectorTests.swift	
@@ -23,6 +23,7 @@ final class LanguageDetectorTests: XCTestCase {
             ("main.yml", "yaml"),
             ("main.toml", "toml"),
             ("main.csv", "csv"),
+            ("main.txt", "plain"),
             ("main.ini", "ini"),
             ("main.md", "markdown"),
             ("main.proto", "proto"),
@@ -104,4 +105,16 @@ final class LanguageDetectorTests: XCTestCase {
         let result = LanguageDetector.shared.detect(text: "", name: nil, fileURL: nil)
         XCTAssertEqual(result.lang, "plain")
     }
+
+    func testMarkdownExtensionNotOverriddenBySQLHeuristics() {
+        let text = """
+        # History vision
+
+        Concrete API plan:
+        SELECT endpoint, method FROM api_catalog WHERE active = 1;
+        """
+        let url = URL(fileURLWithPath: "/tmp/History vision Concrete API plan.md")
+        let result = LanguageDetector.shared.detect(text: text, name: url.lastPathComponent, fileURL: url)
+        XCTAssertEqual(result.lang, "markdown")
+    }
 }