diff --git a/src/SUMMARY.md b/src/SUMMARY.md
index 350f5961..2cf408a1 100644
--- a/src/SUMMARY.md
+++ b/src/SUMMARY.md
@@ -2,9 +2,12 @@
 
 [Rust语言圣经](about-book.md)
 [进入 Rust 编程世界](into-rust.md)
-[AWS 为何这么喜欢 Rust?](usecases/aws-rust.md)
 [快速查询入口](index-list.md)
 
+---
+[Rust Cookbook](cookbook.md)
+[Rust 语言周刊](rust-weekly.md)
+[Rustt 翻译计划](rustt.md)
 
 # 快速开始
 ---
@@ -164,9 +167,9 @@
 
 # 应用实战
 ---
-- [Cookbook](cookbook.md)
-- [Rust 语言周刊](rust-weekly.md)
-- [Rustt 翻译计划](rustt.md)
+- [企业落地实践](usecases/intro.md)
+  - [AWS 为何这么喜欢 Rust?](usecases/aws-rust.md)
+
 - [Rust 最佳实践](practice/intro.md)
   - [对抗编译检查](practice/fight-with-compiler/intro.md)
     - [生命周期](practice/fight-with-compiler/lifetime/intro.md)
diff --git a/theme/style2.css b/theme/style2.css
index e4d5a8cd..eacea892 100644
--- a/theme/style2.css
+++ b/theme/style2.css
@@ -97,4 +97,12 @@ table {
 /* Fix on mobile device */
 code {
     word-break: break-word;
+}
+
+/* 修改书侧边目录的区域分隔行样式 */
+
+.chapter .spacer {
+    background-color: #99CCFF;
+    height: 2px;
+    margin-top: 8px;
 }
\ No newline at end of file