diff --git a/.gitignore b/.gitignore
index d7f3e09b2..39b33d86b 100644
--- a/.gitignore
+++ b/.gitignore
@@ -4,6 +4,7 @@
 /node_modules
 /.pnp
 .pnp.js
+package-lock.json
 
 # testing
 /coverage
diff --git a/.gitmodules b/.gitmodules
index da43b7ef9..1df6737fc 100644
--- a/.gitmodules
+++ b/.gitmodules
@@ -1,3 +1,6 @@
 [submodule "pages/article/Wiki"]
 	path = pages/article/Wiki
 	url = https://github.com/FreeCodeCamp-Chengdu/Wiki
+[submodule "pages/article/PPT"]
+	path = pages/article/PPT
+	url = https://github.com/FreeCodeCamp-Chengdu/Activity_PPT
diff --git a/next-env.d.ts b/next-env.d.ts
index 52e831b43..254b73c16 100644
--- a/next-env.d.ts
+++ b/next-env.d.ts
@@ -1,5 +1,6 @@
 /// <reference types="next" />
 /// <reference types="next/image-types/global" />
+/// <reference path="./.next/types/routes.d.ts" />
 
 // NOTE: This file should not be edited
 // see https://nextjs.org/docs/pages/api-reference/config/typescript for more information.
diff --git a/pages/api/core.ts b/pages/api/core.ts
index 5003a5af4..65bad72ce 100644
--- a/pages/api/core.ts
+++ b/pages/api/core.ts
@@ -85,22 +85,24 @@ export async function* pageListOf(path: string, prefix = 'pages'): AsyncGenerato
     name = name.replace(MDX_pattern, '');
     path = `${path}/${name}`.replace(new RegExp(`^${prefix}`), '');
 
-    if (node.isFile() && isMDX) {
-      const article: ArticleMeta = { name, path, subs: [] };
-      try {
-        const meta = await frontMatterOf(`${node.path}/${node.name}`);
+    if (node.isFile()) {
+      const article: ArticleMeta = { name: isMDX ? name : node.name, path, subs: [] };
 
-        if (meta) article.meta = meta;
-      } catch (error) {
-        console.error(`Error reading front matter for ${node.path}/${node.name}:`, error);
-      }
-      yield article;
-    }
-    if (!node.isDirectory()) continue;
+      if (isMDX)
+        try {
+          const meta = await frontMatterOf(`${node.path}/${node.name}`);
 
-    const subs = await Array.fromAsync(pageListOf(path, prefix));
+          if (meta) article.meta = meta;
+        } catch (error) {
+          console.error(`Error reading front matter for ${node.path}/${node.name}:`, error);
+        }
 
-    if (subs.length) yield { name, subs };
+      yield article;
+    } else if (node.isDirectory()) {
+      const subs = await Array.fromAsync(pageListOf(path, prefix));
+
+      if (subs.length) yield { name, subs };
+    }
   }
 }
 
diff --git a/pages/article/PPT b/pages/article/PPT
new file mode 160000
index 000000000..144859de4
--- /dev/null
+++ b/pages/article/PPT
@@ -0,0 +1 @@
+Subproject commit 144859de471707164a51a94b61caaef6f6a7f76f
diff --git a/pages/article/index.tsx b/pages/article/index.tsx
index c845517e6..a54bdfc53 100644
--- a/pages/article/index.tsx
+++ b/pages/article/index.tsx
@@ -16,7 +16,7 @@ export const getStaticProps = async () => {
 const renderTree = (list: ArticleMeta[]) => (
   <ol>
     {list.map(({ name, path, meta, subs }) => (
-      <li key={name}>
+      <li key={path || name}>
         {path ? (
           <a
             className="h4 d-flex justify-content-between align-items-center"