任务1和任务2写一块了

1 month ago · 03a4e816e8
parent 5e0cc09485
commit 03a4e816e8
1 changed files with 72 additions and 0 deletions
--- a/任务1和任务2.html
+++ b/任务1和任务2.html
@ -0,0 +1,72 @@
 <!DOCTYPE html>
 <html lang="en">
 <head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Document</title>
 </head>
 <body>
    <div class="header">
        我是头部
    </div>
    <div class="main">
        <div class="content">
            秒杀模块
        </div>
    </div>
    <!--回到顶部按钮-->
    <div id="toTop" style="position: fixed; bottom: 70px; right: 50px; border-radius: 50%; background-color: rgba(0,0,0,0.1); height: 30px;width: 30px; display: none;flex-direction: column; justify-content: center; align-items: center;">
        <img src="./assets/top.png" style="height: 20px; width: 20px;" alt="">
    </div>
 </body>
 <style>
    .header{
        position: fixed;
        top: -80px;
        left: 0;
        width: 100%;
        height: 80px;
        background-color: skyblue;
        text-align: center;
        color: #fff;
        line-height: 80px;
        font-size: 30px;
        transition: all 0.3s;
    }
    .main{
        height: 1800px;
        width: 1000px;
        background-color: pink;
    }
    .content{
        position: absolute;
        top: 500px;
        background-color: gray;
    }
 </style>
 <script>
    const content = document.querySelector('.content')
    const header = document.querySelector('.header')
    const toTop = document.querySelector('#toTop')
    window.addEventListener('scroll',function(){
        const n = document.documentElement.scrollTop
        let viewScrollTop = document.documentElement.scrollTop
        if(n>=content.offsetTop){
            header.style.top = 0
        }else{
            header.style.top = '-80px'
        }
        if(viewScrollTop>400){
            toTop.style.display = 'flex'
        }else{
            toTop.style.display = 'none'
        }
    })
    toTop.addEventListener('click',()=>{
        document.documentElement.scrollTop = 0
    })
 </script>
 </html>