diff --git a/.editorconfig b/.editorconfig
new file mode 100644
index 0000000..c9c9253
--- /dev/null
+++ b/.editorconfig
@@ -0,0 +1,21 @@
+# .gitattributes settles what git stores; this settles what an editor writes.
+# Git has no concept of encoding, so a byte-order mark is content it preserves
+# rather than normalizes - which is how this repository ended up with both forms.
+
+root = true
+
+[*.cs]
+charset = utf-8
+end_of_line = crlf
+insert_final_newline = true
+
+# Windows PowerShell 5.1 treats BOM-less files as the system code page.
+[*.ps1]
+charset = utf-8-bom
+end_of_line = crlf
+insert_final_newline = true
+
+[*.{sh,bash}]
+charset = utf-8
+end_of_line = lf
+insert_final_newline = true
diff --git a/sources/LineEndingNormalizer.Tests/BomlessUtf32RefusalTests.cs b/sources/LineEndingNormalizer.Tests/BomlessUtf32RefusalTests.cs
index 1f5e732..f462a3c 100644
--- a/sources/LineEndingNormalizer.Tests/BomlessUtf32RefusalTests.cs
+++ b/sources/LineEndingNormalizer.Tests/BomlessUtf32RefusalTests.cs
@@ -1,4 +1,4 @@
-using System.Text;
+using System.Text;
 
 namespace LineEndingNormalizer.Tests;
 
diff --git a/sources/LineEndingNormalizer.Tests/LosslessFileWriterTests.cs b/sources/LineEndingNormalizer.Tests/LosslessFileWriterTests.cs
index e11592d..f397f75 100644
--- a/sources/LineEndingNormalizer.Tests/LosslessFileWriterTests.cs
+++ b/sources/LineEndingNormalizer.Tests/LosslessFileWriterTests.cs
@@ -1,4 +1,4 @@
-using System.ComponentModel;
+using System.ComponentModel;
 using System.Text;
 
 namespace LineEndingNormalizer.Tests;
diff --git a/sources/LineEndingNormalizer.Tests/ProgramEndToEndTests.cs b/sources/LineEndingNormalizer.Tests/ProgramEndToEndTests.cs
index 2b67b81..776fb50 100644
--- a/sources/LineEndingNormalizer.Tests/ProgramEndToEndTests.cs
+++ b/sources/LineEndingNormalizer.Tests/ProgramEndToEndTests.cs
@@ -1,4 +1,4 @@
-using System.Text;
+using System.Text;
 
 namespace LineEndingNormalizer.Tests;
 
diff --git a/sources/LineEndingNormalizer/BomlessUnicodeSafety.cs b/sources/LineEndingNormalizer/BomlessUnicodeSafety.cs
index 8e49821..48824b1 100644
--- a/sources/LineEndingNormalizer/BomlessUnicodeSafety.cs
+++ b/sources/LineEndingNormalizer/BomlessUnicodeSafety.cs
@@ -1,4 +1,4 @@
-using System.Buffers;
+using System.Buffers;
 using System.Text;
 
 namespace LineEndingNormalizer;
diff --git a/sources/LineEndingNormalizer/ConversionRefusedException.cs b/sources/LineEndingNormalizer/ConversionRefusedException.cs
index 59ed98a..1f6746b 100644
--- a/sources/LineEndingNormalizer/ConversionRefusedException.cs
+++ b/sources/LineEndingNormalizer/ConversionRefusedException.cs
@@ -1,4 +1,4 @@
-namespace LineEndingNormalizer;
+namespace LineEndingNormalizer;
 
 /// <summary>
 /// Identifies a file that LEN deliberately left unchanged because conversion
diff --git a/sources/LineEndingNormalizer/FilePatternMatcher.cs b/sources/LineEndingNormalizer/FilePatternMatcher.cs
index 0416d13..46b241b 100644
--- a/sources/LineEndingNormalizer/FilePatternMatcher.cs
+++ b/sources/LineEndingNormalizer/FilePatternMatcher.cs
@@ -1,4 +1,4 @@
-using System.Text.RegularExpressions;
+using System.Text.RegularExpressions;
 
 namespace LineEndingNormalizer;
 
diff --git a/sources/LineEndingNormalizer/LineEnding.cs b/sources/LineEndingNormalizer/LineEnding.cs
index 3ba0e77..fcb8b69 100644
--- a/sources/LineEndingNormalizer/LineEnding.cs
+++ b/sources/LineEndingNormalizer/LineEnding.cs
@@ -1,4 +1,4 @@
-namespace LineEndingNormalizer;
+namespace LineEndingNormalizer;
 
 /// <summary>
 /// Supported output line-ending styles.
diff --git a/sources/LineEndingNormalizer/LosslessFileWriter.cs b/sources/LineEndingNormalizer/LosslessFileWriter.cs
index adb90a6..3ac5d66 100644
--- a/sources/LineEndingNormalizer/LosslessFileWriter.cs
+++ b/sources/LineEndingNormalizer/LosslessFileWriter.cs
@@ -1,4 +1,4 @@
-using System.Buffers;
+using System.Buffers;
 using System.ComponentModel;
 using System.IO.Hashing;
 using System.Runtime.InteropServices;
diff --git a/sources/LineEndingNormalizer/NewLineNormalizer.cs b/sources/LineEndingNormalizer/NewLineNormalizer.cs
index f32b72a..7dd14f7 100644
--- a/sources/LineEndingNormalizer/NewLineNormalizer.cs
+++ b/sources/LineEndingNormalizer/NewLineNormalizer.cs
@@ -1,4 +1,4 @@
-namespace LineEndingNormalizer;
+namespace LineEndingNormalizer;
 
 /// <summary>
 /// Detects encodings and normalizes line endings while preserving
diff --git a/sources/LineEndingNormalizer/Options.cs b/sources/LineEndingNormalizer/Options.cs
index 6c38a9c..c680652 100644
--- a/sources/LineEndingNormalizer/Options.cs
+++ b/sources/LineEndingNormalizer/Options.cs
@@ -1,4 +1,4 @@
-namespace LineEndingNormalizer;
+namespace LineEndingNormalizer;
 
 /// <summary>
 /// Command-line options.
diff --git a/sources/LineEndingNormalizer/Program.cs b/sources/LineEndingNormalizer/Program.cs
index fbec55f..464dfb5 100644
--- a/sources/LineEndingNormalizer/Program.cs
+++ b/sources/LineEndingNormalizer/Program.cs
@@ -1,4 +1,4 @@
-using System.ComponentModel;
+using System.ComponentModel;
 using System.Diagnostics.CodeAnalysis;
 using System.Text;
 using System.Text.RegularExpressions;
diff --git a/sources/LineEndingNormalizer/TextEncoding.cs b/sources/LineEndingNormalizer/TextEncoding.cs
index 47f1090..8b50b4c 100644
--- a/sources/LineEndingNormalizer/TextEncoding.cs
+++ b/sources/LineEndingNormalizer/TextEncoding.cs
@@ -1,4 +1,4 @@
-using System.Text;
+using System.Text;
 using System.Buffers;
 using UtfUnknown;
 
diff --git a/sources/LineEndingNormalizer/TextValidation.cs b/sources/LineEndingNormalizer/TextValidation.cs
index 4b9a090..99516e9 100644
--- a/sources/LineEndingNormalizer/TextValidation.cs
+++ b/sources/LineEndingNormalizer/TextValidation.cs
@@ -1,4 +1,4 @@
-using System.Buffers;
+using System.Buffers;
 using System.Globalization;
 using System.Text;
 
diff --git a/sources/LineEndingNormalizer/UnicodeDetector.cs b/sources/LineEndingNormalizer/UnicodeDetector.cs
index 4ca50b0..26b9ce8 100644
--- a/sources/LineEndingNormalizer/UnicodeDetector.cs
+++ b/sources/LineEndingNormalizer/UnicodeDetector.cs
@@ -1,4 +1,4 @@
-using System;
+using System;
 using System.Text;
 
 namespace LineEndingNormalizer;