diff --git a/Makefile b/Makefile
index 989583c..4a02855 100644
--- a/Makefile
+++ b/Makefile
@@ -212,11 +212,11 @@ bench-check:
 
 # 格式化代码（使用 goimports 替代 go fmt）
 fmt:
-	@echo "Formatting code with goimports..."
-	@if command -v goimports >/dev/null 2>&1; then \
-		goimports -w .; \
+	@echo "Formatting code with gofumpt..."
+	@if command -v gofumpt >/dev/null 2>&1; then \
+		gofumpt -w .; \
 	else \
-		echo "goimports not installed. Run: go install golang.org/x/tools/cmd/goimports@latest"; \
+		echo "gofumpt not installed. Run: go install mvdan.cc/gofumpt@latest"; \
 		exit 1; \
 	fi
 
diff --git a/internal/app/app_windows.go b/internal/app/app_windows.go
index 421dd5e..740a924 100644
--- a/internal/app/app_windows.go
+++ b/internal/app/app_windows.go
@@ -91,7 +91,7 @@ func generateConfig(outputPath string) int {
 	if outputPath == "" {
 		fmt.Print(string(yamlData))
 	} else {
-		if err := os.WriteFile(outputPath, yamlData, 0644); err != nil {
+		if err := os.WriteFile(outputPath, yamlData, 0o644); err != nil {
 			fmt.Fprintf(os.Stderr, "写入文件失败: %v\n", err)
 			return 1
 		}
diff --git a/internal/handler/sendfile_other_test.go b/internal/handler/sendfile_other_test.go
index 68a622e..c8a8c9f 100644
--- a/internal/handler/sendfile_other_test.go
+++ b/internal/handler/sendfile_other_test.go
@@ -29,7 +29,7 @@ func TestPlatformSendfile_NonLinux(t *testing.T) {
 	tmpDir := t.TempDir()
 	tmpFile := filepath.Join(tmpDir, "test.txt")
 	content := []byte("test content")
-	if err := os.WriteFile(tmpFile, content, 0644); err != nil {
+	if err := os.WriteFile(tmpFile, content, 0o644); err != nil {
 		t.Fatalf("Failed to create temp file: %v", err)
 	}
 
@@ -51,7 +51,7 @@ func TestCopyFile(t *testing.T) {
 	tmpFile := filepath.Join(tmpDir, "test.txt")
 
 	content := []byte("Hello, World! This is test content for copyFile.")
-	if err := os.WriteFile(tmpFile, content, 0644); err != nil {
+	if err := os.WriteFile(tmpFile, content, 0o644); err != nil {
 		t.Fatalf("Failed to create temp file: %v", err)
 	}
 
@@ -132,7 +132,7 @@ func TestSendFile_SmallFile(t *testing.T) {
 	tmpFile := filepath.Join(tmpDir, "small.txt")
 
 	content := []byte("small file content")
-	if err := os.WriteFile(tmpFile, content, 0644); err != nil {
+	if err := os.WriteFile(tmpFile, content, 0o644); err != nil {
 		t.Fatalf("Failed to create temp file: %v", err)
 	}
 
@@ -161,7 +161,7 @@ func TestSendFile_WithOffset(t *testing.T) {
 	tmpFile := filepath.Join(tmpDir, "test.txt")
 
 	content := []byte("0123456789ABCDEF")
-	if err := os.WriteFile(tmpFile, content, 0644); err != nil {
+	if err := os.WriteFile(tmpFile, content, 0o644); err != nil {
 		t.Fatalf("Failed to create temp file: %v", err)
 	}
 
@@ -190,7 +190,7 @@ func TestSendFile_ZeroLength(t *testing.T) {
 	tmpDir := t.TempDir()
 	tmpFile := filepath.Join(tmpDir, "empty.txt")
 
-	if err := os.WriteFile(tmpFile, []byte{}, 0644); err != nil {
+	if err := os.WriteFile(tmpFile, []byte{}, 0o644); err != nil {
 		t.Fatalf("Failed to create temp file: %v", err)
 	}
 
@@ -228,7 +228,7 @@ func TestCopyFile_Error(t *testing.T) {
 	tmpFile := filepath.Join(tmpDir, "test.txt")
 
 	content := []byte("test content")
-	if err := os.WriteFile(tmpFile, content, 0644); err != nil {
+	if err := os.WriteFile(tmpFile, content, 0o644); err != nil {
 		t.Fatalf("Failed to create temp file: %v", err)
 	}
 
diff --git a/internal/handler/static_bench_test.go b/internal/handler/static_bench_test.go
index 8c3a601..e9af0f8 100644
--- a/internal/handler/static_bench_test.go
+++ b/internal/handler/static_bench_test.go
@@ -31,10 +31,10 @@ func setupStaticTestDir() (string, func()) {
 
 	for path, content := range testFiles {
 		fullPath := filepath.Join(dir, path)
-		if err := os.MkdirAll(filepath.Dir(fullPath), 0755); err != nil {
+		if err := os.MkdirAll(filepath.Dir(fullPath), 0o755); err != nil {
 			panic(err)
 		}
-		if err := os.WriteFile(fullPath, content, 0644); err != nil {
+		if err := os.WriteFile(fullPath, content, 0o644); err != nil {
 			panic(err)
 		}
 	}
diff --git a/internal/handler/static_test.go b/internal/handler/static_test.go
index cde3d6e..247cd3e 100644
--- a/internal/handler/static_test.go
+++ b/internal/handler/static_test.go
@@ -53,7 +53,7 @@ func TestStaticHandlerHandle(t *testing.T) {
 			setup: func(t *testing.T, root string) {
 				t.Helper()
 				content := "hello world"
-				if err := os.WriteFile(filepath.Join(root, "test.txt"), []byte(content), 0644); err != nil {
+				if err := os.WriteFile(filepath.Join(root, "test.txt"), []byte(content), 0o644); err != nil {
 					t.Fatalf("创建测试文件失败: %v", err)
 				}
 			},
@@ -66,11 +66,11 @@ func TestStaticHandlerHandle(t *testing.T) {
 			setup: func(t *testing.T, root string) {
 				t.Helper()
 				subDir := filepath.Join(root, "sub", "dir")
-				if err := os.MkdirAll(subDir, 0755); err != nil {
+				if err := os.MkdirAll(subDir, 0o755); err != nil {
 					t.Fatalf("创建子目录失败: %v", err)
 				}
 				content := "nested file content"
-				if err := os.WriteFile(filepath.Join(subDir, "nested.txt"), []byte(content), 0644); err != nil {
+				if err := os.WriteFile(filepath.Join(subDir, "nested.txt"), []byte(content), 0o644); err != nil {
 					t.Fatalf("创建嵌套文件失败: %v", err)
 				}
 			},
@@ -83,11 +83,11 @@ func TestStaticHandlerHandle(t *testing.T) {
 			setup: func(t *testing.T, root string) {
 				t.Helper()
 				dir := filepath.Join(root, "withindex")
-				if err := os.MkdirAll(dir, 0755); err != nil {
+				if err := os.MkdirAll(dir, 0o755); err != nil {
 					t.Fatalf("创建目录失败: %v", err)
 				}
 				content := "index page"
-				if err := os.WriteFile(filepath.Join(dir, "index.html"), []byte(content), 0644); err != nil {
+				if err := os.WriteFile(filepath.Join(dir, "index.html"), []byte(content), 0o644); err != nil {
 					t.Fatalf("创建索引文件失败: %v", err)
 				}
 			},
@@ -100,7 +100,7 @@ func TestStaticHandlerHandle(t *testing.T) {
 			setup: func(t *testing.T, root string) {
 				t.Helper()
 				dir := filepath.Join(root, "noindex")
-				if err := os.MkdirAll(dir, 0755); err != nil {
+				if err := os.MkdirAll(dir, 0o755); err != nil {
 					t.Fatalf("创建目录失败: %v", err)
 				}
 			},
@@ -133,7 +133,7 @@ func TestStaticHandlerHandle(t *testing.T) {
 			setup: func(t *testing.T, root string) {
 				t.Helper()
 				content := "root index"
-				if err := os.WriteFile(filepath.Join(root, "index.html"), []byte(content), 0644); err != nil {
+				if err := os.WriteFile(filepath.Join(root, "index.html"), []byte(content), 0o644); err != nil {
 					t.Fatalf("创建根索引文件失败: %v", err)
 				}
 			},
@@ -256,7 +256,7 @@ func TestStaticHandlerHandle_PathTraversalSecurity(t *testing.T) {
 			setup: func(t *testing.T, root string) {
 				t.Helper()
 				// 创建目标文件供测试
-				if err := os.WriteFile(filepath.Join(root, "bar.txt"), []byte("bar"), 0644); err != nil {
+				if err := os.WriteFile(filepath.Join(root, "bar.txt"), []byte("bar"), 0o644); err != nil {
 					t.Fatalf("创建文件失败: %v", err)
 				}
 			},
@@ -288,15 +288,15 @@ func TestStaticHandlerHandle_IndexFallback(t *testing.T) {
 	t.Run("优先 index.html", func(t *testing.T) {
 		tmpDir := t.TempDir()
 		dir := filepath.Join(tmpDir, "testdir")
-		if err := os.MkdirAll(dir, 0755); err != nil {
+		if err := os.MkdirAll(dir, 0o755); err != nil {
 			t.Fatalf("创建目录失败: %v", err)
 		}
 
 		// 创建两个索引文件
-		if err := os.WriteFile(filepath.Join(dir, "index.html"), []byte("html content"), 0644); err != nil {
+		if err := os.WriteFile(filepath.Join(dir, "index.html"), []byte("html content"), 0o644); err != nil {
 			t.Fatalf("创建 index.html 失败: %v", err)
 		}
-		if err := os.WriteFile(filepath.Join(dir, "index.htm"), []byte("htm content"), 0644); err != nil {
+		if err := os.WriteFile(filepath.Join(dir, "index.htm"), []byte("htm content"), 0o644); err != nil {
 			t.Fatalf("创建 index.htm 失败: %v", err)
 		}
 
@@ -318,12 +318,12 @@ func TestStaticHandlerHandle_IndexFallback(t *testing.T) {
 	t.Run("无 index.html 时使用 index.htm", func(t *testing.T) {
 		tmpDir := t.TempDir()
 		dir := filepath.Join(tmpDir, "testdir")
-		if err := os.MkdirAll(dir, 0755); err != nil {
+		if err := os.MkdirAll(dir, 0o755); err != nil {
 			t.Fatalf("创建目录失败: %v", err)
 		}
 
 		// 仅创建 index.htm
-		if err := os.WriteFile(filepath.Join(dir, "index.htm"), []byte("htm content"), 0644); err != nil {
+		if err := os.WriteFile(filepath.Join(dir, "index.htm"), []byte("htm content"), 0o644); err != nil {
 			t.Fatalf("创建 index.htm 失败: %v", err)
 		}
 
@@ -344,12 +344,12 @@ func TestStaticHandlerHandle_IndexFallback(t *testing.T) {
 	t.Run("无索引文件时返回 403", func(t *testing.T) {
 		tmpDir := t.TempDir()
 		dir := filepath.Join(tmpDir, "testdir")
-		if err := os.MkdirAll(dir, 0755); err != nil {
+		if err := os.MkdirAll(dir, 0o755); err != nil {
 			t.Fatalf("创建目录失败: %v", err)
 		}
 
 		// 创建一个非索引文件
-		if err := os.WriteFile(filepath.Join(dir, "other.txt"), []byte("other content"), 0644); err != nil {
+		if err := os.WriteFile(filepath.Join(dir, "other.txt"), []byte("other content"), 0o644); err != nil {
 			t.Fatalf("创建 other.txt 失败: %v", err)
 		}
 
@@ -365,12 +365,12 @@ func TestStaticHandlerHandle_IndexFallback(t *testing.T) {
 	t.Run("目录不带斜杠结尾", func(t *testing.T) {
 		tmpDir := t.TempDir()
 		dir := filepath.Join(tmpDir, "testdir")
-		if err := os.MkdirAll(dir, 0755); err != nil {
+		if err := os.MkdirAll(dir, 0o755); err != nil {
 			t.Fatalf("创建目录失败: %v", err)
 		}
 
 		// 创建索引文件
-		if err := os.WriteFile(filepath.Join(dir, "index.html"), []byte("index"), 0644); err != nil {
+		if err := os.WriteFile(filepath.Join(dir, "index.html"), []byte("index"), 0o644); err != nil {
 			t.Fatalf("创建 index.html 失败: %v", err)
 		}
 
@@ -447,7 +447,7 @@ func TestStaticHandler_SetGzipStatic(t *testing.T) {
 func TestStaticHandler_Handle_HeadRequest(t *testing.T) {
 	tmpDir := t.TempDir()
 	content := "head request test"
-	if err := os.WriteFile(filepath.Join(tmpDir, "test.txt"), []byte(content), 0644); err != nil {
+	if err := os.WriteFile(filepath.Join(tmpDir, "test.txt"), []byte(content), 0o644); err != nil {
 		t.Fatalf("创建测试文件失败: %v", err)
 	}
 
@@ -474,7 +474,7 @@ func TestStaticHandler_Handle_HeadRequest(t *testing.T) {
 func TestStaticHandler_Handle_WithCache(t *testing.T) {
 	tmpDir := t.TempDir()
 	content := "cached content test"
-	if err := os.WriteFile(filepath.Join(tmpDir, "test.txt"), []byte(content), 0644); err != nil {
+	if err := os.WriteFile(filepath.Join(tmpDir, "test.txt"), []byte(content), 0o644); err != nil {
 		t.Fatalf("创建测试文件失败: %v", err)
 	}
 
@@ -498,13 +498,13 @@ func TestStaticHandler_Handle_Precompressed(t *testing.T) {
 
 	// 创建原始文件和 gzip 压缩版本
 	content := "test content for gzip"
-	if err := os.WriteFile(filepath.Join(tmpDir, "test.txt"), []byte(content), 0644); err != nil {
+	if err := os.WriteFile(filepath.Join(tmpDir, "test.txt"), []byte(content), 0o644); err != nil {
 		t.Fatalf("创建测试文件失败: %v", err)
 	}
 
 	// 创建 .gz 文件（模拟预压缩）
 	gzContent := []byte("gzipped content")
-	if err := os.WriteFile(filepath.Join(tmpDir, "test.txt.gz"), gzContent, 0644); err != nil {
+	if err := os.WriteFile(filepath.Join(tmpDir, "test.txt.gz"), gzContent, 0o644); err != nil {
 		t.Fatalf("创建 gzip 文件失败: %v", err)
 	}
 
@@ -534,7 +534,7 @@ func TestStaticHandler_Handle_LargeFile(t *testing.T) {
 	}
 
 	tmpFile := filepath.Join(tmpDir, "large.bin")
-	if err := os.WriteFile(tmpFile, largeContent, 0644); err != nil {
+	if err := os.WriteFile(tmpFile, largeContent, 0o644); err != nil {
 		t.Fatalf("创建大文件失败: %v", err)
 	}
 
@@ -558,7 +558,7 @@ func TestStaticHandler_Handle_Symlink(t *testing.T) {
 	// 创建目标文件
 	targetContent := "symlink target"
 	targetFile := filepath.Join(tmpDir, "target.txt")
-	if err := os.WriteFile(targetFile, []byte(targetContent), 0644); err != nil {
+	if err := os.WriteFile(targetFile, []byte(targetContent), 0o644); err != nil {
 		t.Fatalf("创建目标文件失败: %v", err)
 	}
 
@@ -724,7 +724,7 @@ func TestStaticHandler_handleTryFiles(t *testing.T) {
 		{
 			name: "$uri 找到文件",
 			setup: func(t *testing.T, root string) {
-				if err := os.WriteFile(filepath.Join(root, "app.js"), []byte("app content"), 0644); err != nil {
+				if err := os.WriteFile(filepath.Join(root, "app.js"), []byte("app content"), 0o644); err != nil {
 					t.Fatalf("创建文件失败: %v", err)
 				}
 			},
@@ -737,10 +737,10 @@ func TestStaticHandler_handleTryFiles(t *testing.T) {
 			name: "$uri 未找到回退到 $uri/",
 			setup: func(t *testing.T, root string) {
 				dir := filepath.Join(root, "assets")
-				if err := os.MkdirAll(dir, 0755); err != nil {
+				if err := os.MkdirAll(dir, 0o755); err != nil {
 					t.Fatalf("创建目录失败: %v", err)
 				}
-				if err := os.WriteFile(filepath.Join(dir, "index.html"), []byte("assets index"), 0644); err != nil {
+				if err := os.WriteFile(filepath.Join(dir, "index.html"), []byte("assets index"), 0o644); err != nil {
 					t.Fatalf("创建索引文件失败: %v", err)
 				}
 			},
@@ -752,7 +752,7 @@ func TestStaticHandler_handleTryFiles(t *testing.T) {
 		{
 			name: "回退到 fallback 文件",
 			setup: func(t *testing.T, root string) {
-				if err := os.WriteFile(filepath.Join(root, "index.html"), []byte("spa fallback"), 0644); err != nil {
+				if err := os.WriteFile(filepath.Join(root, "index.html"), []byte("spa fallback"), 0o644); err != nil {
 					t.Fatalf("创建 fallback 文件失败: %v", err)
 				}
 			},
@@ -774,7 +774,7 @@ func TestStaticHandler_handleTryFiles(t *testing.T) {
 		{
 			name: "嵌套目录回退",
 			setup: func(t *testing.T, root string) {
-				if err := os.WriteFile(filepath.Join(root, "app.html"), []byte("app shell"), 0644); err != nil {
+				if err := os.WriteFile(filepath.Join(root, "app.html"), []byte("app shell"), 0o644); err != nil {
 					t.Fatalf("创建 fallback 文件失败: %v", err)
 				}
 			},
@@ -787,10 +787,10 @@ func TestStaticHandler_handleTryFiles(t *testing.T) {
 			name: "路径前缀剥离",
 			setup: func(t *testing.T, root string) {
 				apiDir := filepath.Join(root, "api")
-				if err := os.MkdirAll(apiDir, 0755); err != nil {
+				if err := os.MkdirAll(apiDir, 0o755); err != nil {
 					t.Fatalf("创建目录失败: %v", err)
 				}
-				if err := os.WriteFile(filepath.Join(apiDir, "data.json"), []byte("json data"), 0644); err != nil {
+				if err := os.WriteFile(filepath.Join(apiDir, "data.json"), []byte("json data"), 0o644); err != nil {
 					t.Fatalf("创建文件失败: %v", err)
 				}
 			},
@@ -802,7 +802,7 @@ func TestStaticHandler_handleTryFiles(t *testing.T) {
 		{
 			name: "空 try_files 数组",
 			setup: func(t *testing.T, root string) {
-				if err := os.WriteFile(filepath.Join(root, "test.txt"), []byte("test"), 0644); err != nil {
+				if err := os.WriteFile(filepath.Join(root, "test.txt"), []byte("test"), 0o644); err != nil {
 					t.Fatalf("创建文件失败: %v", err)
 				}
 			},
@@ -853,7 +853,7 @@ func TestStaticHandler_handleInternalRedirect(t *testing.T) {
 		{
 			name: "tryFilesPass false 直接服务文件",
 			setup: func(t *testing.T, root string) {
-				if err := os.WriteFile(filepath.Join(root, "index.html"), []byte("index content"), 0644); err != nil {
+				if err := os.WriteFile(filepath.Join(root, "index.html"), []byte("index content"), 0o644); err != nil {
 					t.Fatalf("创建文件失败: %v", err)
 				}
 			},
@@ -866,7 +866,7 @@ func TestStaticHandler_handleInternalRedirect(t *testing.T) {
 		{
 			name: "tryFilesPass true 触发重定向",
 			setup: func(t *testing.T, root string) {
-				if err := os.WriteFile(filepath.Join(root, "fallback.txt"), []byte("fallback content"), 0644); err != nil {
+				if err := os.WriteFile(filepath.Join(root, "fallback.txt"), []byte("fallback content"), 0o644); err != nil {
 					t.Fatalf("创建文件失败: %v", err)
 				}
 			},
@@ -891,11 +891,11 @@ func TestStaticHandler_handleInternalRedirect(t *testing.T) {
 			name: "内部重定向目标是目录",
 			setup: func(t *testing.T, root string) {
 				dir := filepath.Join(root, "fallback")
-				if err := os.MkdirAll(dir, 0755); err != nil {
+				if err := os.MkdirAll(dir, 0o755); err != nil {
 					t.Fatalf("创建目录失败: %v", err)
 				}
 				// 在 fallback 目录中创建一个 index.html
-				if err := os.WriteFile(filepath.Join(dir, "index.html"), []byte("fallback index"), 0644); err != nil {
+				if err := os.WriteFile(filepath.Join(dir, "index.html"), []byte("fallback index"), 0o644); err != nil {
 					t.Fatalf("创建 index.html 失败: %v", err)
 				}
 			},
@@ -957,19 +957,19 @@ func TestStaticHandler_TryFilesSPA(t *testing.T) {
 
 	// 创建 SPA 文件结构
 	// index.html - 主应用入口
-	if err := os.WriteFile(filepath.Join(tmpDir, "index.html"), []byte("<!DOCTYPE html><html><body>SPA App</body></html>"), 0644); err != nil {
+	if err := os.WriteFile(filepath.Join(tmpDir, "index.html"), []byte("<!DOCTYPE html><html><body>SPA App</body></html>"), 0o644); err != nil {
 		t.Fatalf("创建 index.html 失败: %v", err)
 	}
 
 	// 静态资源文件
 	assetsDir := filepath.Join(tmpDir, "assets")
-	if err := os.MkdirAll(assetsDir, 0755); err != nil {
+	if err := os.MkdirAll(assetsDir, 0o755); err != nil {
 		t.Fatalf("创建 assets 目录失败: %v", err)
 	}
-	if err := os.WriteFile(filepath.Join(assetsDir, "app.js"), []byte("console.log('app')"), 0644); err != nil {
+	if err := os.WriteFile(filepath.Join(assetsDir, "app.js"), []byte("console.log('app')"), 0o644); err != nil {
 		t.Fatalf("创建 app.js 失败: %v", err)
 	}
-	if err := os.WriteFile(filepath.Join(assetsDir, "style.css"), []byte("body { margin: 0 }"), 0644); err != nil {
+	if err := os.WriteFile(filepath.Join(assetsDir, "style.css"), []byte("body { margin: 0 }"), 0o644); err != nil {
 		t.Fatalf("创建 style.css 失败: %v", err)
 	}
 
@@ -1037,15 +1037,15 @@ func TestStaticHandler_TryFilesWithPathPrefix(t *testing.T) {
 
 	// 创建 API 模拟文件
 	apiDir := filepath.Join(tmpDir, "api")
-	if err := os.MkdirAll(apiDir, 0755); err != nil {
+	if err := os.MkdirAll(apiDir, 0o755); err != nil {
 		t.Fatalf("创建 api 目录失败: %v", err)
 	}
-	if err := os.WriteFile(filepath.Join(apiDir, "users.json"), []byte("[]"), 0644); err != nil {
+	if err := os.WriteFile(filepath.Join(apiDir, "users.json"), []byte("[]"), 0o644); err != nil {
 		t.Fatalf("创建 users.json 失败: %v", err)
 	}
 
 	// 创建静态文件
-	if err := os.WriteFile(filepath.Join(tmpDir, "index.html"), []byte("static index"), 0644); err != nil {
+	if err := os.WriteFile(filepath.Join(tmpDir, "index.html"), []byte("static index"), 0o644); err != nil {
 		t.Fatalf("创建 index.html 失败: %v", err)
 	}
 
@@ -1113,7 +1113,7 @@ func TestStaticHandler_Alias(t *testing.T) {
 		{
 			name: "alias 基础替换",
 			setup: func(t *testing.T, aliasDir string) {
-				if err := os.WriteFile(filepath.Join(aliasDir, "logo.png"), []byte("png content"), 0644); err != nil {
+				if err := os.WriteFile(filepath.Join(aliasDir, "logo.png"), []byte("png content"), 0o644); err != nil {
 					t.Fatalf("创建文件失败: %v", err)
 				}
 			},
@@ -1127,10 +1127,10 @@ func TestStaticHandler_Alias(t *testing.T) {
 			name: "alias 嵌套路径",
 			setup: func(t *testing.T, aliasDir string) {
 				subDir := filepath.Join(aliasDir, "icons")
-				if err := os.MkdirAll(subDir, 0755); err != nil {
+				if err := os.MkdirAll(subDir, 0o755); err != nil {
 					t.Fatalf("创建目录失败: %v", err)
 				}
-				if err := os.WriteFile(filepath.Join(subDir, "app.png"), []byte("app icon"), 0644); err != nil {
+				if err := os.WriteFile(filepath.Join(subDir, "app.png"), []byte("app icon"), 0o644); err != nil {
 					t.Fatalf("创建文件失败: %v", err)
 				}
 			},
@@ -1143,7 +1143,7 @@ func TestStaticHandler_Alias(t *testing.T) {
 		{
 			name: "alias 目录索引",
 			setup: func(t *testing.T, aliasDir string) {
-				if err := os.WriteFile(filepath.Join(aliasDir, "index.html"), []byte("alias index"), 0644); err != nil {
+				if err := os.WriteFile(filepath.Join(aliasDir, "index.html"), []byte("alias index"), 0o644); err != nil {
 					t.Fatalf("创建文件失败: %v", err)
 				}
 			},
@@ -1167,7 +1167,7 @@ func TestStaticHandler_Alias(t *testing.T) {
 		{
 			name: "root 与 alias 互斥 - 使用 alias",
 			setup: func(t *testing.T, aliasDir string) {
-				if err := os.WriteFile(filepath.Join(aliasDir, "file.txt"), []byte("from alias"), 0644); err != nil {
+				if err := os.WriteFile(filepath.Join(aliasDir, "file.txt"), []byte("from alias"), 0o644); err != nil {
 					t.Fatalf("创建文件失败: %v", err)
 				}
 			},
@@ -1214,13 +1214,13 @@ func TestStaticHandler_AliasVsRoot(t *testing.T) {
 
 	// 在 root 创建子目录和文件
 	imagesDir := filepath.Join(rootDir, "images")
-	if err := os.MkdirAll(imagesDir, 0755); err != nil {
+	if err := os.MkdirAll(imagesDir, 0o755); err != nil {
 		t.Fatalf("创建 images 目录失败: %v", err)
 	}
-	if err := os.WriteFile(filepath.Join(imagesDir, "logo.png"), []byte("from root"), 0644); err != nil {
+	if err := os.WriteFile(filepath.Join(imagesDir, "logo.png"), []byte("from root"), 0o644); err != nil {
 		t.Fatalf("创建 root 文件失败: %v", err)
 	}
-	if err := os.WriteFile(filepath.Join(aliasDir, "logo.png"), []byte("from alias"), 0644); err != nil {
+	if err := os.WriteFile(filepath.Join(aliasDir, "logo.png"), []byte("from alias"), 0o644); err != nil {
 		t.Fatalf("创建 alias 文件失败: %v", err)
 	}
 
@@ -1299,10 +1299,10 @@ func TestStaticHandler_AliasWithTryFiles(t *testing.T) {
 	aliasDir := t.TempDir()
 
 	// 创建测试文件
-	if err := os.WriteFile(filepath.Join(aliasDir, "app.js"), []byte("app content"), 0644); err != nil {
+	if err := os.WriteFile(filepath.Join(aliasDir, "app.js"), []byte("app content"), 0o644); err != nil {
 		t.Fatalf("创建文件失败: %v", err)
 	}
-	if err := os.WriteFile(filepath.Join(aliasDir, "index.html"), []byte("fallback"), 0644); err != nil {
+	if err := os.WriteFile(filepath.Join(aliasDir, "index.html"), []byte("fallback"), 0o644); err != nil {
 		t.Fatalf("创建文件失败: %v", err)
 	}
 
@@ -1366,7 +1366,7 @@ func TestStaticHandler_TryFilesEdgeCases(t *testing.T) {
 	tmpDir := t.TempDir()
 
 	// 创建测试文件
-	if err := os.WriteFile(filepath.Join(tmpDir, "file with spaces.txt"), []byte("spaces"), 0644); err != nil {
+	if err := os.WriteFile(filepath.Join(tmpDir, "file with spaces.txt"), []byte("spaces"), 0o644); err != nil {
 		t.Fatalf("创建带空格文件失败: %v", err)
 	}
 
@@ -1426,7 +1426,7 @@ func TestStaticHandler_LargeFileContentType(t *testing.T) {
 	for _, tc := range tests {
 		t.Run(tc.ext, func(t *testing.T) {
 			filePath := filepath.Join(tmpDir, "large"+tc.ext)
-			if err := os.WriteFile(filePath, largeContent, 0644); err != nil {
+			if err := os.WriteFile(filePath, largeContent, 0o644); err != nil {
 				t.Fatalf("创建文件失败: %v", err)
 			}
 
@@ -1500,16 +1500,16 @@ func TestStaticHandler_TryFilesWithDynamicSuffix(t *testing.T) {
 	tmpDir := t.TempDir()
 
 	// 创建测试文件
-	if err := os.WriteFile(filepath.Join(tmpDir, "about.html"), []byte("about page"), 0644); err != nil {
+	if err := os.WriteFile(filepath.Join(tmpDir, "about.html"), []byte("about page"), 0o644); err != nil {
 		t.Fatalf("创建文件失败: %v", err)
 	}
-	if err := os.MkdirAll(filepath.Join(tmpDir, "api"), 0755); err != nil {
+	if err := os.MkdirAll(filepath.Join(tmpDir, "api"), 0o755); err != nil {
 		t.Fatalf("创建目录失败: %v", err)
 	}
-	if err := os.WriteFile(filepath.Join(tmpDir, "api", "data.json"), []byte("{\"data\":true}"), 0644); err != nil {
+	if err := os.WriteFile(filepath.Join(tmpDir, "api", "data.json"), []byte("{\"data\":true}"), 0o644); err != nil {
 		t.Fatalf("创建文件失败: %v", err)
 	}
-	if err := os.WriteFile(filepath.Join(tmpDir, "index.html"), []byte("fallback"), 0644); err != nil {
+	if err := os.WriteFile(filepath.Join(tmpDir, "index.html"), []byte("fallback"), 0o644); err != nil {
 		t.Fatalf("创建文件失败: %v", err)
 	}
 
@@ -1563,7 +1563,7 @@ func TestStaticHandler_TryFilesRootPathFallback(t *testing.T) {
 	tmpDir := t.TempDir()
 
 	// 创建 index.html 作为根路径回退
-	if err := os.WriteFile(filepath.Join(tmpDir, "index.html"), []byte("root fallback"), 0644); err != nil {
+	if err := os.WriteFile(filepath.Join(tmpDir, "index.html"), []byte("root fallback"), 0o644); err != nil {
 		t.Fatalf("创建文件失败: %v", err)
 	}
 
diff --git a/internal/loadbalance/balancer.go b/internal/loadbalance/balancer.go
index 17a9fd0..00fa867 100644
--- a/internal/loadbalance/balancer.go
+++ b/internal/loadbalance/balancer.go
@@ -40,10 +40,10 @@ import (
 //
 // 所有字段都设计为使用原子操作进行并发访问（如适用）。
 type Target struct {
+	resolvedIPs   atomic.Pointer[[]string]
 	URL           string
 	hostname      string
 	VirtualHashes []uint64
-	resolvedIPs   atomic.Pointer[[]string]
 	Weight        int
 	Connections   int64
 	lastResolved  atomic.Int64
diff --git a/internal/lua/lua_test.go b/internal/lua/lua_test.go
index 6c39b2b..1769dcf 100644
--- a/internal/lua/lua_test.go
+++ b/internal/lua/lua_test.go
@@ -122,7 +122,7 @@ func TestLuaContextExecuteFile(t *testing.T) {
 	// 创建临时 Lua 文件
 	tmpDir := t.TempDir()
 	scriptPath := filepath.Join(tmpDir, "test.lua")
-	err = os.WriteFile(scriptPath, []byte("return 42"), 0644)
+	err = os.WriteFile(scriptPath, []byte("return 42"), 0o644)
 	require.NoError(t, err)
 
 	// 执行文件
@@ -185,7 +185,7 @@ func TestLuaCoroutineExecuteFile(t *testing.T) {
 	// 创建临时文件
 	tmpDir := t.TempDir()
 	scriptPath := filepath.Join(tmpDir, "test.lua")
-	err = os.WriteFile(scriptPath, []byte("return 42"), 0644)
+	err = os.WriteFile(scriptPath, []byte("return 42"), 0o644)
 	require.NoError(t, err)
 
 	err = coro.ExecuteFile(scriptPath)
@@ -279,7 +279,7 @@ func TestCodeCacheFile(t *testing.T) {
 	scriptPath := filepath.Join(tmpDir, "test.lua")
 	scriptContent := "return 42"
 
-	err := os.WriteFile(scriptPath, []byte(scriptContent), 0644)
+	err := os.WriteFile(scriptPath, []byte(scriptContent), 0o644)
 	require.NoError(t, err)
 
 	cache := NewCodeCache(100, time.Hour, true)
diff --git a/internal/lua/middleware_bench_test.go b/internal/lua/middleware_bench_test.go
index 1e6e9f2..58be33b 100644
--- a/internal/lua/middleware_bench_test.go
+++ b/internal/lua/middleware_bench_test.go
@@ -22,7 +22,7 @@ func BenchmarkLuaMiddlewareOverhead(b *testing.B) {
 	// 创建简单的 Lua 脚本
 	tmpDir := b.TempDir()
 	scriptPath := filepath.Join(tmpDir, "simple.lua")
-	err = os.WriteFile(scriptPath, []byte(`ngx.say("ok")`), 0644)
+	err = os.WriteFile(scriptPath, []byte(`ngx.say("ok")`), 0o644)
 	if err != nil {
 		b.Fatal(err)
 	}
@@ -65,7 +65,7 @@ func BenchmarkLuaMiddlewareMultiPhase(b *testing.B) {
 
 	// rewrite phase
 	rewriteScript := filepath.Join(tmpDir, "rewrite.lua")
-	err = os.WriteFile(rewriteScript, []byte(`-- simple rewrite`), 0644)
+	err = os.WriteFile(rewriteScript, []byte(`-- simple rewrite`), 0o644)
 	if err != nil {
 		b.Fatal(err)
 	}
@@ -76,7 +76,7 @@ func BenchmarkLuaMiddlewareMultiPhase(b *testing.B) {
 
 	// content phase
 	contentScript := filepath.Join(tmpDir, "content.lua")
-	err = os.WriteFile(contentScript, []byte(`ngx.say("content")`), 0644)
+	err = os.WriteFile(contentScript, []byte(`ngx.say("content")`), 0o644)
 	if err != nil {
 		b.Fatal(err)
 	}
@@ -108,7 +108,7 @@ func BenchmarkLuaMiddlewareNgxExit(b *testing.B) {
 
 	tmpDir := b.TempDir()
 	scriptPath := filepath.Join(tmpDir, "exit.lua")
-	err = os.WriteFile(scriptPath, []byte(`ngx.exit(200)`), 0644)
+	err = os.WriteFile(scriptPath, []byte(`ngx.exit(200)`), 0o644)
 	if err != nil {
 		b.Fatal(err)
 	}
@@ -150,7 +150,7 @@ func TestLuaMiddlewarePerformanceOverhead(t *testing.T) {
 
 	tmpDir := t.TempDir()
 	scriptPath := filepath.Join(tmpDir, "perf.lua")
-	err = os.WriteFile(scriptPath, []byte(`ngx.say("performance test")`), 0644)
+	err = os.WriteFile(scriptPath, []byte(`ngx.say("performance test")`), 0o644)
 	if err != nil {
 		t.Fatal(err)
 	}
diff --git a/internal/lua/middleware_test.go b/internal/lua/middleware_test.go
index 57367fe..4f62263 100644
--- a/internal/lua/middleware_test.go
+++ b/internal/lua/middleware_test.go
@@ -21,7 +21,7 @@ func TestLuaMiddlewareCreation(t *testing.T) {
 	// 创建临时脚本文件
 	tmpDir := t.TempDir()
 	scriptPath := filepath.Join(tmpDir, "test.lua")
-	err = os.WriteFile(scriptPath, []byte("ngx.say('hello')"), 0644)
+	err = os.WriteFile(scriptPath, []byte("ngx.say('hello')"), 0o644)
 	require.NoError(t, err)
 
 	config := LuaMiddlewareConfig{
@@ -52,7 +52,7 @@ func TestLuaMiddlewareDefaultConfig(t *testing.T) {
 	// 创建临时脚本文件
 	tmpDir := t.TempDir()
 	scriptPath := filepath.Join(tmpDir, "test.lua")
-	err = os.WriteFile(scriptPath, []byte("return 1"), 0644)
+	err = os.WriteFile(scriptPath, []byte("return 1"), 0o644)
 	require.NoError(t, err)
 
 	// 使用默认配置
@@ -98,7 +98,7 @@ func TestLuaMiddlewareProcess(t *testing.T) {
 	// 创建脚本文件
 	tmpDir := t.TempDir()
 	scriptPath := filepath.Join(tmpDir, "test.lua")
-	err = os.WriteFile(scriptPath, []byte(`ngx.say("hello from lua")`), 0644)
+	err = os.WriteFile(scriptPath, []byte(`ngx.say("hello from lua")`), 0o644)
 	require.NoError(t, err)
 
 	config := LuaMiddlewareConfig{
@@ -139,7 +139,7 @@ func TestLuaMiddlewareDisabled(t *testing.T) {
 	// 创建脚本文件
 	tmpDir := t.TempDir()
 	scriptPath := filepath.Join(tmpDir, "test.lua")
-	err = os.WriteFile(scriptPath, []byte(`ngx.say("lua output")`), 0644)
+	err = os.WriteFile(scriptPath, []byte(`ngx.say("lua output")`), 0o644)
 	require.NoError(t, err)
 
 	config := LuaMiddlewareConfig{
@@ -180,7 +180,7 @@ func TestLuaMiddlewareSetters(t *testing.T) {
 
 	tmpDir := t.TempDir()
 	scriptPath := filepath.Join(tmpDir, "test.lua")
-	err = os.WriteFile(scriptPath, []byte("return 1"), 0644)
+	err = os.WriteFile(scriptPath, []byte("return 1"), 0o644)
 	require.NoError(t, err)
 
 	config := DefaultLuaMiddlewareConfig()
@@ -232,7 +232,7 @@ func TestMultiPhaseLuaMiddlewareAddPhase(t *testing.T) {
 
 	// 添加 rewrite 阶段
 	rewriteScript := filepath.Join(tmpDir, "rewrite.lua")
-	err = os.WriteFile(rewriteScript, []byte("ngx.var.uri = '/rewritten'"), 0644)
+	err = os.WriteFile(rewriteScript, []byte("ngx.var.uri = '/rewritten'"), 0o644)
 	require.NoError(t, err)
 
 	err = multi.AddPhase(PhaseRewrite, rewriteScript, 10*time.Second)
@@ -243,7 +243,7 @@ func TestMultiPhaseLuaMiddlewareAddPhase(t *testing.T) {
 
 	// 添加 access 阶段
 	accessScript := filepath.Join(tmpDir, "access.lua")
-	err = os.WriteFile(accessScript, []byte("ngx.exit(403)"), 0644)
+	err = os.WriteFile(accessScript, []byte("ngx.exit(403)"), 0o644)
 	require.NoError(t, err)
 
 	err = multi.AddPhase(PhaseAccess, accessScript, 10*time.Second)
@@ -264,7 +264,7 @@ func TestMultiPhaseLuaMiddlewareRemovePhase(t *testing.T) {
 	multi := NewMultiPhaseLuaMiddleware(engine, "multi-test")
 
 	scriptPath := filepath.Join(tmpDir, "test.lua")
-	err = os.WriteFile(scriptPath, []byte("return 1"), 0644)
+	err = os.WriteFile(scriptPath, []byte("return 1"), 0o644)
 	require.NoError(t, err)
 
 	err = multi.AddPhase(PhaseRewrite, scriptPath, 10*time.Second)
@@ -289,7 +289,7 @@ func TestMultiPhaseLuaMiddlewareProcess(t *testing.T) {
 
 	// rewrite 阎段脚本
 	rewriteScript := filepath.Join(tmpDir, "rewrite.lua")
-	err = os.WriteFile(rewriteScript, []byte(`ngx.say("rewrite")`), 0644)
+	err = os.WriteFile(rewriteScript, []byte(`ngx.say("rewrite")`), 0o644)
 	require.NoError(t, err)
 
 	err = multi.AddPhase(PhaseRewrite, rewriteScript, 10*time.Second)
@@ -297,7 +297,7 @@ func TestMultiPhaseLuaMiddlewareProcess(t *testing.T) {
 
 	// content 阎段脚本
 	contentScript := filepath.Join(tmpDir, "content.lua")
-	err = os.WriteFile(contentScript, []byte(`ngx.say("content")`), 0644)
+	err = os.WriteFile(contentScript, []byte(`ngx.say("content")`), 0o644)
 	require.NoError(t, err)
 
 	err = multi.AddPhase(PhaseContent, contentScript, 10*time.Second)
@@ -335,7 +335,7 @@ func TestMultiPhaseLuaMiddlewareGetPhaseMiddleware(t *testing.T) {
 	multi := NewMultiPhaseLuaMiddleware(engine, "multi-test")
 
 	scriptPath := filepath.Join(tmpDir, "test.lua")
-	err = os.WriteFile(scriptPath, []byte("return 1"), 0644)
+	err = os.WriteFile(scriptPath, []byte("return 1"), 0o644)
 	require.NoError(t, err)
 
 	err = multi.AddPhase(PhaseRewrite, scriptPath, 10*time.Second)
@@ -360,7 +360,7 @@ func TestLuaMiddlewareIntegrationWithChain(t *testing.T) {
 
 	tmpDir := t.TempDir()
 	scriptPath := filepath.Join(tmpDir, "test.lua")
-	err = os.WriteFile(scriptPath, []byte(`ngx.say("lua middleware")`), 0644)
+	err = os.WriteFile(scriptPath, []byte(`ngx.say("lua middleware")`), 0o644)
 	require.NoError(t, err)
 
 	config := LuaMiddlewareConfig{
@@ -401,7 +401,7 @@ func TestLuaMiddlewareExecutionError(t *testing.T) {
 	// 创建有语法错误的脚本
 	tmpDir := t.TempDir()
 	scriptPath := filepath.Join(tmpDir, "error.lua")
-	err = os.WriteFile(scriptPath, []byte("invalid lua syntax !!!"), 0644)
+	err = os.WriteFile(scriptPath, []byte("invalid lua syntax !!!"), 0o644)
 	require.NoError(t, err)
 
 	config := LuaMiddlewareConfig{
@@ -432,7 +432,7 @@ func TestLuaMiddlewareExit(t *testing.T) {
 
 	tmpDir := t.TempDir()
 	scriptPath := filepath.Join(tmpDir, "exit.lua")
-	err = os.WriteFile(scriptPath, []byte(`ngx.say("before exit"); ngx.exit(200)`), 0644)
+	err = os.WriteFile(scriptPath, []byte(`ngx.say("before exit"); ngx.exit(200)`), 0o644)
 	require.NoError(t, err)
 
 	config := LuaMiddlewareConfig{
diff --git a/internal/proxy/tempfile_cleaner.go b/internal/proxy/tempfile_cleaner.go
index 09cdafc..dc398d3 100644
--- a/internal/proxy/tempfile_cleaner.go
+++ b/internal/proxy/tempfile_cleaner.go
@@ -225,8 +225,10 @@ func (c *TempFileCleaner) CountOrphanFiles() int {
 }
 
 // globalCleaner 全局清理器实例。
-var globalCleaner *TempFileCleaner
-var globalCleanerMu sync.RWMutex
+var (
+	globalCleaner   *TempFileCleaner
+	globalCleanerMu sync.RWMutex
+)
 
 // StartGlobalTempFileCleaner 启动全局临时文件清理器。
 //
diff --git a/internal/proxy/tempfile_test.go b/internal/proxy/tempfile_test.go
index 55a0fd1..bfe5968 100644
--- a/internal/proxy/tempfile_test.go
+++ b/internal/proxy/tempfile_test.go
@@ -427,7 +427,7 @@ func TestTempFileCleaner(t *testing.T) {
 
 		// 创建一个过期的临时文件
 		oldFile := filepath.Join(tempDir, TempFilePrefix+"old")
-		if err := os.WriteFile(oldFile, []byte("old"), 0644); err != nil {
+		if err := os.WriteFile(oldFile, []byte("old"), 0o644); err != nil {
 			t.Fatalf("创建测试文件失败: %v", err)
 		}
 
@@ -439,7 +439,7 @@ func TestTempFileCleaner(t *testing.T) {
 
 		// 创建一个非过期的临时文件
 		newFile := filepath.Join(tempDir, TempFilePrefix+"new")
-		if err := os.WriteFile(newFile, []byte("new"), 0644); err != nil {
+		if err := os.WriteFile(newFile, []byte("new"), 0o644); err != nil {
 			t.Fatalf("创建测试文件失败: %v", err)
 		}
 
@@ -463,7 +463,7 @@ func TestTempFileCleaner(t *testing.T) {
 
 		// 创建一个非 lolly 前缀的文件
 		otherFile := filepath.Join(tempDir, "other-file")
-		if err := os.WriteFile(otherFile, []byte("other"), 0644); err != nil {
+		if err := os.WriteFile(otherFile, []byte("other"), 0o644); err != nil {
 			t.Fatalf("创建测试文件失败: %v", err)
 		}
 
@@ -488,7 +488,7 @@ func TestTempFileCleaner(t *testing.T) {
 
 		// 创建孤儿文件
 		orphanFile := filepath.Join(tempDir, TempFilePrefix+"orphan")
-		if err := os.WriteFile(orphanFile, []byte("orphan"), 0644); err != nil {
+		if err := os.WriteFile(orphanFile, []byte("orphan"), 0o644); err != nil {
 			t.Fatalf("创建测试文件失败: %v", err)
 		}
 
diff --git a/internal/server/status.go b/internal/server/status.go
index 22fa63d..4dec6e4 100644
--- a/internal/server/status.go
+++ b/internal/server/status.go
@@ -145,10 +145,8 @@ func NewStatusHandler(server *Server, cfg *config.StatusConfig) (*StatusHandler,
 			}
 			// 转换为 CIDR 格式
 			if ip.To4() != nil {
-
 				_, network, _ = net.ParseCIDR(cidr + "/32")
 			} else {
-
 				_, network, _ = net.ParseCIDR(cidr + "/128")
 			}
 		}
diff --git a/internal/server/upgrade.go b/internal/server/upgrade.go
index 46a3afe..d65e679 100644
--- a/internal/server/upgrade.go
+++ b/internal/server/upgrade.go
@@ -223,21 +223,18 @@ func (u *UpgradeManager) GracefulUpgrade(newBinary string) error {
 
 	// 写入新 PID 到文件
 	if u.pidFile != "" {
-
 		_ = os.WriteFile(u.pidFile, []byte(fmt.Sprintf("%d", newPid)), 0o644)
 	}
 
 	// 启动 goroutine 等待子进程结束，避免产生僵尸进程
 	// cmd.Wait() 会回收子进程资源，确保不会产生 defunct 进程
 	go func() {
-
 		_ = cmd.Wait()
 	}()
 
 	// 关闭父进程中的文件描述符副本（子进程已继承）
 	// 避免文件描述符泄漏
 	for _, file := range files {
-
 		_ = file.Close()
 	}
 
@@ -334,7 +331,6 @@ func (u *UpgradeManager) SetupSignalHandlers(newBinary string) {
 	go func() {
 		for sig := range sigCh {
 			if sig == syscall.SIGUSR2 {
-
 				_ = u.GracefulUpgrade(newBinary)
 			}
 		}