fix: titlebar does not follow theme in dark mode (#903)

src-tauri/src/commands/misc.rs

@@ -954,3 +954,18 @@ fn run_windows_start_command(args: &[&str], terminal_name: &str) -> Result<(), S
 
     Ok(())
 }
+
+/// 设置窗口主题（Windows/macOS 标题栏颜色）
+/// theme: "dark" | "light" | "system"
+#[tauri::command]
+pub async fn set_window_theme(window: tauri::Window, theme: String) -> Result<(), String> {
+    use tauri::Theme;
+
+    let tauri_theme = match theme.as_str() {
+        "dark" => Some(Theme::Dark),
+        "light" => Some(Theme::Light),
+        _ => None, // system default
+    };
+
+    window.set_theme(tauri_theme).map_err(|e| e.to_string())
+}

src-tauri/src/lib.rs

@@ -956,6 +956,8 @@ pub fn run() {
             commands::test_proxy_url,
             commands::get_upstream_proxy_status,
             commands::scan_local_proxies,
+            // Window theme control
+            commands::set_window_theme,
         ]);
 
     let app = builder