滚动渐变导航栏

实现导航栏固定顶部，且滚动渐变的效果

实现效果

准备html

vscode可利用快捷输入 header>a+ul>li*3>a+tab

<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Document</title>
    <link rel="stylesheet" href="style.css">
</head>
<body>
    <header>
        <a href="#" class="logo">Logo</a>
        <ul>
            <li><a href="#">Home</a></li>
            <li><a href="#">About</a></li>
            <li><a href="#">Contact</a></li>
        </ul>
    </header>
    <section class="banner"></section>
    <script type="text/javascript">
        window.addEventListener("scroll",function(){
            let header = document.querySelector("header");
            header.classList.toggle("sticky",window.scrollY>0)
        })
    </script>
</body>
</html>

准备css

*{
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}
body{
    background-color: #000;
    min-height: 200vh;
}
header{
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    display: flex;
    justify-content: space-between;
    align-items: center;
    transition: .6s;
    padding: 40px 100px;
    z-index: 99;
}
header.sticky{
    padding: 5px 100px;
    background: #fff;
}
header.sticky .logo,
header.sticky ul li a{
    color: #000;
}
header .logo{
    position: relative;
    font-weight: 700;
    color: #fff;
    text-decoration: none;
    font-size: 2em;
    text-transform: uppercase;
    letter-spacing: 2px;
    transition: .6s;
}
header ul{
    position: relative;
    display: flex;
    justify-content: center;
    align-items: center;
}
header ul li{
    position: relative;
    list-style: none;
}
header ul li a{
    position: relative;
    margin: 0 15px;
    text-decoration: none;
    color: #fff;
    letter-spacing: 2px;
    font-weight: 500px;
    transition: .6s;
}
.banner{
    position: relative;
    width: 100%;
    height: 100vh;
    background: url("bg.png");
    background-size: cover;
}