diff --git a/Neon Vision Editor.xcodeproj/project.pbxproj b/Neon Vision Editor.xcodeproj/project.pbxproj
index 6e9b422..668914e 100644
--- a/Neon Vision Editor.xcodeproj/project.pbxproj	
+++ b/Neon Vision Editor.xcodeproj/project.pbxproj	
@@ -361,7 +361,7 @@
 				CODE_SIGNING_ALLOWED = YES;
 				CODE_SIGN_IDENTITY = "Apple Development";
 				CODE_SIGN_STYLE = Automatic;
-				CURRENT_PROJECT_VERSION = 400;
+				CURRENT_PROJECT_VERSION = 401;
 				DEAD_CODE_STRIPPING = YES;
 				DEVELOPMENT_TEAM = CS727NF72U;
 				ENABLE_APP_SANDBOX = YES;
@@ -444,7 +444,7 @@
 				CODE_SIGNING_ALLOWED = YES;
 				CODE_SIGN_IDENTITY = "Apple Development";
 				CODE_SIGN_STYLE = Automatic;
-				CURRENT_PROJECT_VERSION = 400;
+				CURRENT_PROJECT_VERSION = 401;
 				DEAD_CODE_STRIPPING = YES;
 				DEVELOPMENT_TEAM = CS727NF72U;
 				ENABLE_APP_SANDBOX = YES;
diff --git a/Neon Vision Editor/Data/EditorViewModel.swift b/Neon Vision Editor/Data/EditorViewModel.swift
index 83efbca..80d0c61 100644
--- a/Neon Vision Editor/Data/EditorViewModel.swift	
+++ b/Neon Vision Editor/Data/EditorViewModel.swift	
@@ -82,6 +82,10 @@ private enum EditorLoadHelper {
         defer { input.close() }
 
         var aggregate = Data()
+        if let expectedSize = try? url.resourceValues(forKeys: [.fileSizeKey]).fileSize,
+           expectedSize > 0 {
+            aggregate.reserveCapacity(expectedSize)
+        }
         var buffer = [UInt8](repeating: 0, count: streamChunkBytes)
 
         while true {
@@ -1145,7 +1149,13 @@ class EditorViewModel {
 
             let data: Data
             if isLargeCandidate {
-                data = try EditorLoadHelper.streamFileData(from: url)
+                // Prefer memory-mapped IO for very large files to reduce peak memory churn.
+                // Fall back to streaming if mapping is unavailable for the provider.
+                if let mapped = try? Data(contentsOf: url, options: [.mappedIfSafe]) {
+                    data = mapped
+                } else {
+                    data = try EditorLoadHelper.streamFileData(from: url)
+                }
             } else {
                 data = try Data(contentsOf: url, options: [.mappedIfSafe])
             }
diff --git a/Neon Vision Editor/UI/ContentView.swift b/Neon Vision Editor/UI/ContentView.swift
index 24ed0d7..0a12e02 100644
--- a/Neon Vision Editor/UI/ContentView.swift	
+++ b/Neon Vision Editor/UI/ContentView.swift	
@@ -1441,12 +1441,22 @@ struct ContentView: View {
         let exceedsLineThreshold: Bool = {
             if exceedsByteThreshold { return true }
             var lineBreaks = 0
+            var currentLineLength = 0
+            let csvLongLineThreshold = 16_000
             for codeUnit in text.utf16 {
                 if codeUnit == 10 { // '\n'
                     lineBreaks += 1
+                    currentLineLength = 0
                     if lineBreaks >= lineThreshold {
                         return true
                     }
+                    continue
+                }
+                if isCSVLike {
+                    currentLineLength += 1
+                    if currentLineLength >= csvLongLineThreshold {
+                        return true
+                    }
                 }
             }
             return false