diff --git a/_sidebar.md b/_sidebar.md
index 7b9be5d..04ec8be 100644
--- a/_sidebar.md
+++ b/_sidebar.md
@@ -5,7 +5,8 @@
 - Python 基础
     - [Python 介绍](docs/course/foundation/01_introduction.md)
     - [环境配置](docs/course/foundation/02_environment.md)
-    - [第一个 Hello World 程序](docs/course/foundation/03_hello_world.md)
+    - [开发工具](docs/course/foundation/03_development_tools.md)
+    - [第一个 Hello World 程序](docs/course/foundation/04_hello_world.md)
 
 - 其他小工具
     - [JWT](jwt/README.md)
diff --git a/docs/course/foundation/02_environment.md b/docs/course/foundation/02_environment.md
index 4350376..d8e7059 100644
--- a/docs/course/foundation/02_environment.md
+++ b/docs/course/foundation/02_environment.md
@@ -23,9 +23,11 @@
 
 ### 进行安装
 双击运行安装文件
+
 ![python-windows-install-02 (1)|666x410](https://cdn.ossez.com/discourse-uploads/original/1X/73fa20718b774a2e7fc6803ed4b3d30e19d3080e.jpeg)
 
 选择默认安装路径就可以了。
+
 ![python-windows-install-03|666x410](https://cdn.ossez.com/discourse-uploads/original/1X/915ed31bc2afddae08bb8f00f413cd1840e4539b.jpeg)
 
 你需要等待一些时间让安装完成。