diff --git a/02-css-layout/10-fixed-and-sticky/answer.css b/02-css-layout/10-fixed-and-sticky/answer.css
index 3649f46..5a37456 100644
--- a/02-css-layout/10-fixed-and-sticky/answer.css
+++ b/02-css-layout/10-fixed-and-sticky/answer.css
@@ -27,6 +27,7 @@ body {
   background: #ffffff;
   border-bottom: 1px solid #cbd5e1;
   font-weight: 700;
+  width: 100%;
 }
 
 .content {
diff --git a/02-css-layout/10-fixed-and-sticky/starter.html b/02-css-layout/10-fixed-and-sticky/starter.html
index 005d67f..6810a02 100644
--- a/02-css-layout/10-fixed-and-sticky/starter.html
+++ b/02-css-layout/10-fixed-and-sticky/starter.html
@@ -7,8 +7,10 @@
     <style>
       body{
         background-color: rgb(248, 252, 255);
+        margin: 0px;
         display: flex;
         justify-content: center;
+        align-items: center;
       }
 
       a{
@@ -24,7 +26,23 @@
       }
 
       .page{
-        wi
+        width: min(700px,calc(100% - 40px));
+        margin: 0 auto;
+      }
+
+      .topbar{
+        padding: 15px;
+        background-color: white;
+        position: fixed;
+        top: 0px;
+        font-weight: 700;
+        font-size: 17px;
+        width: min(700px,calc(100% - 40px));
+      }
+
+      .content{
+          height: 1100px;
+          margin-top: 60px;
       }
     </style>
   </head>
diff --git a/02-css-layout/11-centering-lab/starter.html b/02-css-layout/11-centering-lab/starter.html
index 0d72667..a1e2806 100644
--- a/02-css-layout/11-centering-lab/starter.html
+++ b/02-css-layout/11-centering-lab/starter.html
@@ -1,14 +1,41 @@
 <!DOCTYPE html>
 <html lang="zh-CN">
-  <head>
-    <meta charset="UTF-8" />
-    <meta name="viewport" content="width=device-width, initial-scale=1.0" />
-    <title>居中专题</title>
-    <link rel="stylesheet" href="./starter.css" />
-  </head>
-  <body>
-    <div class="stage">
-      <div class="box">把我放到中间</div>
-    </div>
-  </body>
-</html>
+
+<head>
+  <meta charset="UTF-8" />
+  <meta name="viewport" content="width=device-width, initial-scale=1.0" />
+  <title>居中专题</title>
+  <style>
+    body {
+      background-color: rgb(255, 248, 238);
+      margin: 0;
+    }
+
+    .stage {
+      background-color: white;
+      border: 1px solid rgba(255, 156, 7, 0.25);
+      border-radius: 20px;
+      padding: 15px 20px;
+      box-shadow: 0 0 10px rgb(243, 218, 172);
+      width: 150px;
+      height: 70px;
+      display: flex;
+      justify-content: center;
+      align-items: center;
+
+    }
+
+    .box {
+      text-align: center;
+      margin: auto;
+    }
+  </style>
+</head>
+
+<body>
+  <div class="stage">
+    <div class="box">把我放到中间</div>
+  </div>
+</body>
+
+</html>
\ No newline at end of file
