diff --git a/chapter_computational_complexity/iteration_and_recursion.md b/chapter_computational_complexity/iteration_and_recursion.md
index e3b43aa67..f8f670cb3 100644
--- a/chapter_computational_complexity/iteration_and_recursion.md
+++ b/chapter_computational_complexity/iteration_and_recursion.md
@@ -1505,7 +1505,7 @@ status: new
 === "JS"
 
     ```javascript title="recursion.js"
-    /* 递归转化为迭代 */
+    /* 使用迭代模拟递归 */
     function forLoopRecur(n) {
         // 使用一个显式的栈来模拟系统调用栈
         const stack = [];
@@ -1528,7 +1528,7 @@ status: new
 === "TS"
 
     ```typescript title="recursion.ts"
-    /* 递归转化为迭代 */
+    /* 使用迭代模拟递归 */
     function forLoopRecur(n: number): number {
         // 使用一个显式的栈来模拟系统调用栈 
         const stack: number[] = [];
diff --git a/stylesheets/extra.css b/stylesheets/extra.css
index b1e71c665..0b99df253 100644
--- a/stylesheets/extra.css
+++ b/stylesheets/extra.css
@@ -25,7 +25,7 @@
   --md-default-fg-color: #adbac7;
   --md-default-bg-color: #22272e;
 
-  --md-code-bg-color: #2D333B;
+  --md-code-bg-color: #1D2126;
   --md-code-fg-color: #adbac7;
 
   --md-accent-fg-color: #aaa;