47 lines
1001 B
HTML
47 lines
1001 B
HTML
<!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 http-equiv="X-UA-Compatible" content="IE=edge">
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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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body {
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margin: 0;
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height: 6000px;
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}
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.header {
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width: 100%;
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background: red;
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height: 50px;
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}
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.fixed {
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position: fixed;
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left: 0;
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top: 0;
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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="header "></div>
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</body>
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<script>
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window.addEventListener("scroll", function () {
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var top = document.documentElement.scrollTop;
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top > 300 ? $(".header").classList.add("fixed") : $(".header").classList.remove("fixed")
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})
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function $(className) {
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return document.querySelector(className)
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}
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function _(className) {
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return document.querySelectorAll(className)
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}
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</script>
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</html> |