diff --git a/docs/.nav.yml b/docs/.nav.yml
index ac5ee2b28..3f99c1616 100644
--- a/docs/.nav.yml
+++ b/docs/.nav.yml
@@ -101,31 +101,50 @@ nav:
   - CI: contributing/ci
   - Design Documents:
     - design/index.md
-    - design/architecture_overview.md
+    - Architecture Documents:
+      - Architecture Overview: design/architecture_overview.md
     - Feature Design:
-      - design/feature/disaggregated_inference.md
-      - design/feature/ray_based_execution.md
-      - design/feature/omni_connectors/
-      - design/feature/prefix_caching.md
-      - design/feature/cfg_parallel.md
-      - design/feature/expert_parallel.md
-      - design/feature/sequence_parallel.md
-      - design/feature/tensor_parallel.md
-      - design/feature/vae_parallel.md
-      - design/feature/hsdp.md
-      - design/feature/cache_dit.md
-      - design/feature/teacache.md
-      - design/feature/skip_softmax.md
-      - design/feature/async_chunk.md
-      - design/feature/omni_async_output_materialization.md
-      - design/feature/vae_parallel.md
-      - design/feature/diffusion_continuous_batching.md
-      - design/feature/distributed_layerwise_offload.md
+      - Runtime and Stage Execution:
+        - Disaggregated Inference: design/feature/disaggregated_inference.md
+        - Ray-based Execution: design/feature/ray_based_execution.md
+        - Async Chunk: design/feature/async_chunk.md
+        - Async Diffusion Output: design/feature/async_diffusion_output.md
+        - Async Omni Output Materialization: design/feature/omni_async_output_materialization.md
+        - Automatic Prefix Caching: design/feature/prefix_caching.md
+      - Communication:
+        - OmniConnector Implementations:
+          - Mooncake Store Connector: design/feature/omni_connectors/mooncake_store_connector.md
+          - Mooncake Transfer Engine Connector: design/feature/omni_connectors/mooncake_transfer_engine_connector.md
+          - Mori Transfer Engine Connector: design/feature/omni_connectors/mori_transfer_engine_connector.md
+          - Shared Memory Connector: design/feature/omni_connectors/shared_memory_connector.md
+          - Yuanrong Store Connector: design/feature/omni_connectors/yuanrong_connector.md
+          - Yuanrong Transfer Engine Connector: design/feature/omni_connectors/yuanrong_transfer_engine_connector.md
+      - Diffusion Acceleration:
+        - Parallelism:
+          - CFG-Parallel: design/feature/cfg_parallel.md
+          - Expert Parallel: design/feature/expert_parallel.md
+          - Hybrid Sharded Data Parallel (HSDP): design/feature/hsdp.md
+          - Pipeline Parallel: design/feature/pipeline_parallel.md
+          - Sequence Parallel: design/feature/sequence_parallel.md
+          - Tensor Parallel: design/feature/tensor_parallel.md
+          - VAE Patch Parallelism: design/feature/vae_parallel.md
+        - Attention Backends:
+          - Skip-Softmax: design/feature/skip_softmax.md
+        - Quantization: user_guide/quantization/overview.md
+        - Cache-DiT: design/feature/cache_dit.md
+        - TeaCache: design/feature/teacache.md
+        - Diffusion Continuous Batching: design/feature/diffusion_continuous_batching.md
+        - Distributed Layerwise Offload: design/feature/distributed_layerwise_offload.md
+    - Infrastructure and Performance:
+      - Prometheus Metrics: design/metrics.md
+      - Speech Generation Performance Optimizations: design/qwen3_omni_tts_performance_optimization.md
     - Module Design:
-      - design/module/ar_module.md
-      - design/module/dit_module.md
-      - design/module/entrypoint_module.md
-      - design/module/async_omni_architecture.md
+      - Runtime Modules:
+        - AR Module: design/module/ar_module.md
+        - DIT Module: design/module/dit_module.md
+      - Orchestration:
+        - Entrypoint Module: design/module/entrypoint_module.md
+        - AsyncOmni Architecture: design/module/async_omni_architecture.md
   - Docs Guide: contributing/DOCS_GUIDE.md
 - API Reference:
   - api/README.md
diff --git a/docs/design/index.md b/docs/design/index.md
index e8df11b77..57fd9ba4c 100644
--- a/docs/design/index.md
+++ b/docs/design/index.md
@@ -1,6 +1,8 @@
 # Design Documents
 
-This section contains design documents and architecture specifications for vLLM-Omni.
+This section contains design documents and architecture specifications for
+vLLM-Omni. The sidebar groups documents by the system concern they describe,
+while the source paths remain stable so existing links continue to work.
 
 ## Architecture Documents
 
@@ -8,18 +10,64 @@ This section contains design documents and architecture specifications for vLLM-
 
 ## Feature Design Documents
 
+### Runtime and stage execution
+
 - [Disaggregated Inference](feature/disaggregated_inference.md)
 - [Ray-based Execution](feature/ray_based_execution.md)
+- [Async Chunk](feature/async_chunk.md)
+- [Async Diffusion Output](feature/async_diffusion_output.md)
 - [Async Omni Output Materialization](feature/omni_async_output_materialization.md)
+- [Automatic Prefix Caching in Omni Models](feature/prefix_caching.md)
+
+### Communication
+
+#### OmniConnector implementations
+
+- [Mooncake Store Connector](feature/omni_connectors/mooncake_store_connector.md)
+- [Mooncake Transfer Engine Connector](feature/omni_connectors/mooncake_transfer_engine_connector.md)
+- [Mori Transfer Engine Connector](feature/omni_connectors/mori_transfer_engine_connector.md)
+- [Shared Memory Connector](feature/omni_connectors/shared_memory_connector.md)
+- [Yuanrong Store Connector](feature/omni_connectors/yuanrong_connector.md)
+- [Yuanrong Transfer Engine Connector](feature/omni_connectors/yuanrong_transfer_engine_connector.md)
+
+### Diffusion acceleration
+
+#### Parallelism
+
+- [CFG-Parallel](feature/cfg_parallel.md)
+- [Expert Parallel](feature/expert_parallel.md)
+- [Hybrid Sharded Data Parallel (HSDP)](feature/hsdp.md)
+- [Pipeline Parallel](feature/pipeline_parallel.md)
+- [Sequence Parallel](feature/sequence_parallel.md)
+- [Tensor Parallel](feature/tensor_parallel.md)
+- [VAE Patch Parallelism](feature/vae_parallel.md)
+
+#### Attention Backends
+
+- [Skip-Softmax](feature/skip_softmax.md)
+
+#### Quantization
+
+- [Quantization Overview](../user_guide/quantization/overview.md)
+
+- [Cache-DiT](feature/cache_dit.md)
+- [TeaCache](feature/teacache.md)
 - [Diffusion Continuous Batching](feature/diffusion_continuous_batching.md)
 - [Distributed Layerwise Offload](feature/distributed_layerwise_offload.md)
 
-## Infrastructure Design Documents
+## Infrastructure and Performance
 
 - [Prometheus Metrics](metrics.md)
+- [Speech Generation Performance Optimizations](qwen3_omni_tts_performance_optimization.md)
 
 ## Module Design Documents
 
+### Runtime Modules
+
 - [AR Module](module/ar_module.md)
 - [DIT Module](module/dit_module.md)
+
+### Orchestration
+
 - [Entrypoint Module](module/entrypoint_module.md)
+- [AsyncOmni Architecture (Qwen3-Omni Example)](module/async_omni_architecture.md)