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47 lines
1.2 KiB
47 lines
1.2 KiB
<!DOCTYPE html>
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<html lang="en">
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<head>
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<meta charset="UTF-8">
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<meta name="viewport" content="width=device-width, initial-scale=1.0">
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<title>Document</title>
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<style>
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.box1{
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position: fixed;
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width: 100%;
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height: 50px;
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background-color: #e4e4e4;
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text-align: center;
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line-height: 50px;
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top:-80px;
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}
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.box2{
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width: 100%;
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height: 1800px;
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background-color: pink;
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display: flex;
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align-items: center;
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}
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.box3{
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width: 200px;
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background-color: aqua;
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}
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</style>
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</head>
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<body>
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<div class="box1">我又出现了</div>
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<div class="box2">
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<div class="box3">滑到这里再出现</div>
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</div>
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<script>
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const box1=document.querySelector('.box1')
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const box3=document.querySelector('.box3')
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window.addEventListener('scroll',function(){
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const n=document.documentElement.scrollTop
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box1.style.top=n>=box3.offsetTop ? 0 : '-80px'
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})
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</script>
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</body>
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</html> |