diff --git a/.gitignore b/.gitignore
index c42bc3e..6b44854 100644
--- a/.gitignore
+++ b/.gitignore
@@ -3,5 +3,4 @@ www/
 site_libs/
 BB/Ref.bib
 _variables.yml
-_extensions/
 .Rproj.user/
diff --git a/SD/20240321_3_Excel基础/index.qmd b/SD/20240321_3_Excel基础/index.qmd
index c288aad..30eba8d 100644
--- a/SD/20240321_3_Excel基础/index.qmd
+++ b/SD/20240321_3_Excel基础/index.qmd
@@ -35,6 +35,11 @@ require(tidyverse)
 require(learnr)
 ```
 
+## 下载excel文件
+
+[https://drwater.rcees.ac.cn/git/course/RWEP/raw/branch/main/data/airquality.xlsx](https://drwater.rcees.ac.cn/git/course/RWEP/raw/branch/main/data/airquality.xlsx)
+
+
 ## Tidy data
 
 由Hadley Wickham提出，tidy data 是一种结构化数据的组织方式，使得数据分析和可视化等操作更加简单、直观和有效。它有助于减少数据的混乱和复杂性，并促进数据的整洁性和易用性。
@@ -121,6 +126,7 @@ require(learnr)
 - DATE：返回指定年、月、日的日期
 - TIME：返回指定小时、分钟、秒的时间
 
+
 ## 欢迎讨论！{.center}
 
 
diff --git a/_extensions/inst/css/revealjs.css b/_extensions/inst/css/revealjs.css
index 965e972..c6e4a50 100644
--- a/_extensions/inst/css/revealjs.css
+++ b/_extensions/inst/css/revealjs.css
@@ -154,6 +154,14 @@ section#TOC a:hover {
   list-style-type: circle;
 }
 
+li:hover {
+  font-weight: bold;
+}
+
+.reveal p:hover {
+  font-weight: bold;
+}
+
 .reveal ul li {
   line-height: 1.2em;
 }
@@ -315,6 +323,11 @@ figure > figcaption {
     font-size: x-large;
 }
 
+.reveal pre code:hover{
+    font-size: xx-large;
+  line-height: 250%;
+}
+
 section#title-slide p.subtitle {
     font-size: var(--r-heading3-size);
     text-decoration: none;
@@ -326,3 +339,7 @@ section#title-slide p.subtitle {
     min-height: 100%;
     font-size: x-large;
 }
+
+.reveal div.sourceCode pre code:hover {
+    font-size: xx-large;
+}
diff --git a/_quarto.yml b/_quarto.yml
index 656e14c..2a0c2ca 100644
--- a/_quarto.yml
+++ b/_quarto.yml
@@ -23,7 +23,7 @@ website:
   page-navigation: true
   page-footer: "Copyright 2024, [Ming Su](https://drwater.rcees.ac.cn)"
   navbar:
-    background: "light"
+    background: "grey"
     search: true
     right:
       - icon: house