如何为响应式导航菜单添加上滑入/下滑收起的切换动画？

需求说明 #

为响应式导航菜单添加两个效果：

1. 菜单展开时上滑入动画
2. 点击切换按钮时页面滑回顶部

已实现菜单显示/隐藏的基础功能，需优化动画表现。

实现步骤 #

1. 替换display属性实现上滑入动画 #

原生display: none/block无法触发CSS过渡动画，改用max-height+opacity结合过渡属性，实现平滑滑入效果：

修改CSS中.lista-nav和.active的样式：

.lista-nav {
    list-style-type: none;
    width: 100%;
    text-align: center;
    padding-top: 15px;
    /* 替换display:none为以下属性 */
    max-height: 0;
    opacity: 0;
    overflow: hidden;
    transition: max-height 0.3s ease-out, opacity 0.3s ease-out;
}

.active {
    /* 替换display:block为以下属性，max-height设为菜单实际高度的最大值即可 */
    max-height: 300px;
    opacity: 1;
}

2. 添加切换时滑回顶部功能 #

在JavaScript的点击事件中加入页面滚动逻辑：

const toggleButton = document.getElementById('toggleButton');
const naviList = document.getElementById('navi-lista');

toggleButton.addEventListener('click', () => {
    naviList.classList.toggle('active');
    // 添加滑回顶部代码
    window.scrollTo({
        top: 0,
        behavior: 'smooth' // 平滑滚动，移除则为瞬间跳转
    });
})

完整修改后代码 #

JavaScript #

const toggleButton = document.getElementById('toggleButton');
const naviList = document.getElementById('navi-lista');

toggleButton.addEventListener('click', () => {
    naviList.classList.toggle('active');
    window.scrollTo({
        top: 0,
        behavior: 'smooth'
    });
})

CSS #

* {
    font-family: 'Lato', sans-serif;
    box-sizing: border-box;
    margin: 0px;
    padding: 0px;
}

body {
    background-color: #856547;
}

.rodzicnav {
    position: fixed;
    top: 0;
    left: 0;
    margin: auto;
    width: 100%;
}

.navbar {
    background-color: rgb(31, 31, 31);
    align-items: center;
    color: white;
    display: flex;
    justify-content: space-around;
    font-size: 18px;
}

.primary-icon {
    height: 30px;
}

.lista-nav {
    list-style-type: none;
}

.lista-nav .elementlisty {
    display: inline-block;
    padding: 20px;
}

.navbar a {
    color: white;
    text-decoration: none;
}

.grow { 
    transition: all .2s ease-in-out; 
}
    
.grow:hover { 
    transform: scale(1.1); 
}

.menu {
    display: none;
}

.menu-line {
    width: 25px;
    height: 3px;
    background-color: white;
    margin-bottom: 4px;
}

@media all and (min-width: 480px) {
    
    .navbar {
        flex-direction: column;
    }

    .menu {
        display: block;
        position: absolute;
        right: 15px;
        top: 15px;
        cursor: pointer;
    }

    .lista-nav .elementlisty {
        display: block;
        padding: 10px;
        border-top: solid 1px white;
    }

    .lista-nav {
        list-style-type: none;
        width: 100%;
        text-align: center;
        padding-top: 15px;
        max-height: 0;
        opacity: 0;
        overflow: hidden;
        transition: max-height 0.3s ease-out, opacity 0.3s ease-out;
    }
    
    .logo-kontener {
        width: 100%;
    }

    .primary-icon {
        margin-left: 10px;
        margin-top: 10px;
    }

    .active {
        max-height: 300px;
        opacity: 1;
    }

}

HTML #

<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta http-equiv="X-UA-Compatible" content="IE=edge">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">

    <!-- FONT  -->
    <link rel="preconnect" href="https://fonts.googleapis.com">
    <link rel="preconnect" href="https://fonts.gstatic.com" crossorigin>
    <link href="https://fonts.googleapis.com/css2?family=Lato:wght@300&display=swap" rel="stylesheet">
    <!--       -->

    <link href="https://unpkg.com/aos@2.3.1/dist/aos.css" rel="stylesheet">
    <link rel="stylesheet" href="style.css">
    
    <title></title>
    <script src="https://cdnjs.cloudflare.com/ajax/libs/gsap/3.11.3/gsap.min.js" defer></script>
    <script src="script.js" defer></script>
</head>
<body>

<div class="rodzicnav">
    <nav class="navbar">
        <div class="logo-kontener">
            <a href=""><img class="primary-icon" src="obrazy/logo.png" alt=""></a>
        </div>
        <ul class="lista-nav" id="navi-lista">
            <li class="elementlisty grow">
                <a href="">O nas</a>
            </li>
            <li class="elementlisty grow">
                <a href="">Realizacje</a>
            </li>
            <li class="elementlisty grow">
                <a href="">Kontakt</a>
            </li>
        </ul>
        <div class="menu" id="toggleButton">
            <div class="menu-line"></div>
            <div class="menu-line"></div>
            <div class="menu-line"></div>
        </div>
    </nav>
</div>

</body>
</html>

内容的提问来源于stack exchange，提问作者Kondzioo