diff --git a/docs/async.md b/docs/async.md
index 589234e..5f2afcc 100644
--- a/docs/async.md
+++ b/docs/async.md
@@ -1,7 +1,7 @@
 ---
 layout: default
 title: "Async"
-parent: Core Abstraction
+parent: "Core Abstraction"
 nav_order: 5
 ---
 
diff --git a/docs/batch.md b/docs/batch.md
index bc53d00..1f987e6 100644
--- a/docs/batch.md
+++ b/docs/batch.md
@@ -1,7 +1,7 @@
 ---
 layout: default
 title: "Batch"
-parent: Core Abstraction
+parent: "Core Abstraction"
 nav_order: 4
 ---
 
diff --git a/docs/communication.md b/docs/communication.md
index 3e00552..6efe873 100644
--- a/docs/communication.md
+++ b/docs/communication.md
@@ -1,7 +1,7 @@
 ---
 layout: default
 title: "Communication"
-parent: Core Abstraction
+parent: "Core Abstraction"
 nav_order: 3
 ---
 
diff --git a/docs/core_abstraction.md b/docs/core_abstraction.md
new file mode 100644
index 0000000..5ef824b
--- /dev/null
+++ b/docs/core_abstraction.md
@@ -0,0 +1,14 @@
+---
+layout: default
+title: "Core Abstraction"
+nav_order: 3
+has_children: true
+---
+
+## Core Abstraction
+
+- [Node](./node.md)
+- [Flow](./flow.md)
+- [Communication](./communication.md)
+- [Batch](./batch.md)
+- [Async](./async.md)
diff --git a/docs/flow.md b/docs/flow.md
index 7e2fcb1..570b24e 100644
--- a/docs/flow.md
+++ b/docs/flow.md
@@ -1,7 +1,7 @@
 ---
 layout: default
 title: "Flow"
-parent: Core Abstraction
+parent: "Core Abstraction"
 nav_order: 2
 ---
 
diff --git a/docs/node.md b/docs/node.md
index 022f235..27b235f 100644
--- a/docs/node.md
+++ b/docs/node.md
@@ -1,7 +1,7 @@
 ---
 layout: default
 title: "Node"
-parent: Core Abstraction
+parent: "Core Abstraction"
 nav_order: 1
 ---
 
@@ -10,7 +10,7 @@ nav_order: 1
 A **Node** is the smallest building block of Mini LLM Flow. Each Node has three lifecycle methods:
 
 1. **`prep(shared)`**  
-   - Optionally preprocess data before calling your LLM or doing heavy computation.
+   - Optionally preprocess data before calling your LLM or doing heavy computation. 
    - Often used for tasks like reading files, chunking text, or validation.
    - Returns `prep_res`, which will be passed to both `exec()` and `post()`.