diff --git a/shared/rules/wpf/index.md b/shared/rules/wpf/index.md
index 59a49fe..2f5ba9e 100644
--- a/shared/rules/wpf/index.md
+++ b/shared/rules/wpf/index.md
@@ -1,34 +1,12 @@
-# WPF Code Guidelines
+# WPF Rules
 
-* Use modern C# and current .NET/WPF conventions.
-* Keep UI, application logic and domain logic clearly separated.
-* Prefer MVVM for non-trivial views.
-* Keep code-behind minimal.
-* Use code-behind only for view-specific behavior that does not belong in the ViewModel.
-* Avoid business logic in views.
-* Avoid direct service access from controls.
-* Keep dependencies explicit and testable.
-* Prefer composition over inheritance.
-* Avoid unnecessary abstractions and framework wrappers.
-* Follow the existing project architecture unless there is a strong reason to change it.
+For WPF, XAML, or MVVM work, open only the focused topic rules relevant to the change.
 
-## Safety Rule
-
-* The UI must remain responsive.
-* Do not block the UI thread with I/O or expensive CPU work.
-* Do not bypass validation or security controls for convenience.
-* Do not introduce hidden cross-thread access.
-* Prefer predictable, explicit and testable UI behavior.
-
-## Detailed guidance
-
-Read the matching reference file before working in that area:
-
-| Read this reference for... | ...this kind of work |
-| --- | --- |
-| `references/mvvm-and-binding.md` | MVVM, data binding, property change notifications, dependency/attached properties |
-| `references/commands-and-async.md` | Commands, async/threading, UI-thread work, events |
-| `references/collections-and-xaml.md` | Collections, virtualization, layout, XAML |
-| `references/resources-and-lifecycle.md` | Resources/styles, windows/dialogs, navigation, memory, images/media |
-| `references/security-and-errors.md` | Security, file/process access, error handling, logging, validation |
-| `references/architecture-and-quality.md` | Architecture, DI, testing, code quality, performance |
+| Topic | Codex rule | Claude skill |
+| --- | --- | --- |
+| MVVM and binding | `references/mvvm-and-binding.md` | `rules-wpf-mvvm-and-binding` |
+| Commands, async, and threading | `references/commands-and-async.md` | `rules-wpf-commands-and-async` |
+| Collections and XAML | `references/collections-and-xaml.md` | `rules-wpf-collections-and-xaml` |
+| Resources and lifecycle | `references/resources-and-lifecycle.md` | `rules-wpf-resources-and-lifecycle` |
+| Security and errors | `references/security-and-errors.md` | `rules-wpf-security-and-errors` |
+| Architecture, testing, and performance | `references/architecture-and-quality.md` | `rules-wpf-architecture-and-quality` |
diff --git a/shared/rules/wpf/references/architecture-and-quality.md b/shared/rules/wpf/references/architecture-and-quality.md
index 1f6d588..b2113b6 100644
--- a/shared/rules/wpf/references/architecture-and-quality.md
+++ b/shared/rules/wpf/references/architecture-and-quality.md
@@ -1,5 +1,8 @@
 ## Architecture
 
+* Use modern C# and current WPF conventions. Prefer MVVM for non-trivial views and keep code-behind limited to view-specific behavior.
+* Keep UI, application, and domain logic separate. Avoid business logic in views and direct service access from controls.
+* Keep dependencies explicit and testable; prefer composition over inheritance and avoid unnecessary abstractions or framework wrappers.
 * Keep presentation, application, domain and infrastructure concerns separated.
 * Avoid direct database access from views or ViewModels.
 * Avoid direct HTTP access from controls.
diff --git a/shared/rules/wpf/references/commands-and-async.md b/shared/rules/wpf/references/commands-and-async.md
index 5a51164..921e1cc 100644
--- a/shared/rules/wpf/references/commands-and-async.md
+++ b/shared/rules/wpf/references/commands-and-async.md
@@ -28,6 +28,7 @@
 ## UI Thread
 
 * Treat the UI thread as a scarce resource.
+* Keep the interface responsive and do not block the UI thread with I/O or expensive CPU work. Move CPU work off-thread only when needed and marshal UI changes back explicitly.
 * Avoid expensive loops, parsing, serialization, database access or network calls on the UI thread.
 * Avoid excessive Dispatcher invocations.
 * Batch UI updates where practical.