From d89427dbf91c92ca62605408cf7abbc23998a07c Mon Sep 17 00:00:00 2001
From: pw5sib4uf <3246282016@qq.com>
Date: Fri, 18 Oct 2024 22:59:17 +0800
Subject: [PATCH] =?UTF-8?q?=E5=AF=BC=E8=88=AA=E6=A0=8F=E7=9A=84=E5=9C=A8?=
 =?UTF-8?q?=E7=BA=BF?=
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

---
 导航栏再现.html | 47 ++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 47 insertions(+)
 create mode 100644 导航栏再现.html
diff --git a/导航栏再现.html b/导航栏再现.html
new file mode 100644
index 0000000..eb32a36
--- /dev/null
+++ b/导航栏再现.html
@@ -0,0 +1,47 @@
+<!DOCTYPE html>
+<html lang="en">
+<head>
+    <meta charset="UTF-8">
+    <meta name="viewport" content="width=device-width, initial-scale=1.0">
+    <title>Document</title>
+    <style>
+        .box1{
+            position: fixed;
+            width: 100%;
+            height: 50px;
+            background-color: #e4e4e4;
+            text-align: center;
+            line-height: 50px;
+            top:-80px;
+            
+        }
+        .box2{
+            width: 100%;
+            height: 1800px;
+            background-color: pink;
+           display: flex;
+           align-items: center;
+           
+        }
+        .box3{
+            width: 200px;
+            background-color: aqua;
+        }
+    </style>
+</head>
+<body>
+    <div class="box1">我又出现了</div>
+    <div class="box2">
+        <div class="box3">滑到这里再出现</div>
+    </div>
+    <script>
+        const box1=document.querySelector('.box1')
+        const box3=document.querySelector('.box3')
+        window.addEventListener('scroll',function(){
+            const n=document.documentElement.scrollTop
+     box1.style.top=n>=box3.offsetTop ? 0 : '-80px'
+
+})
+    </script>
+</body>
+</html>
\ No newline at end of file
