一个不怎么成功的三级菜单

news2025/1/13 9:47:51

三级菜单制作，菜单焦点总是消失，等发现好的再写一篇
发现父元素设置了display:flex时，子元素中的display:none或者display:block就会失效。这是因为display:flex的优先级高于display:none和display:block，使他们的作用失效了。解决办法是在子元素的外层，原来父元素的内层套一个盒子，比如div，display:none就能作用了。

完成效果
在这里插入图片描述

准备html

<!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>
        <div class="menu-bar">
    <ul>
        <li class="active"><a href="#">Home</a></li>
        <li>
            <a href="#">Language</a>
            <div class="sub-menu-1">
                <ul>
                    <li class="hover-2">
                        <a href="#">前端&nbsp&nbsp></a>
                        <div class="sub-menu-2">
                            <ul>
                                <li><a href="#">JS</a></li>
                                <li><a href="#">html</a></li>
                                <li><a href="#">css</a></li>
                            </ul>
                        </div>
                    </li>
                    <li class="hover-2">
                        <a href="#">后端</a>
                        <div class="sub-menu-2">
                            <ul>
                                <li><a href="#">Python</a></li>
                                <li><a href="#">Node</a></li>
                                <li><a href="#">Go</a></li>
                                <li><a href="#">C#</a></li>
                                <li><a href="#">Sql</a></li>
                            </ul>
                        </div>
                    </li>
                </ul>
            </div>
        </li>
        <li><a href="#">About</a></li>
        <li><a href="#">More</a></li>
        <li><a href="#">Contact</a></li>
    </ul>
</div>
</header>
</body>
</html>

准备css

*{
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}
.menu-bar{
    background: #000;
    text-align: center;
}
.menu-bar ul{
    display: inline-flex;
    list-style: none;
    color: #fff;
}
.menu-bar ul li{
    width: 120px;
    margin: 15px;
    padding: 15px;
}
.menu-bar ul li a{
    text-decoration: none;
    color: #fff;
}
.active,.menu-bar ul li:hover{
    background: green;
    border-radius: 3px;
}
.sub-menu-1{
    display: none;
}
.menu-bar ul li:hover .sub-menu-1{
    display: block;
    position: absolute;
    background: green;
    margin-top: 15px;
    margin-left: -15px;
}
.menu-bar ul li:hover .sub-menu-1 ul{
    display: block;
    margin: 10px;
}
.menu-bar ul li:hover .sub-menu-1 ul li{
    width: 75px;
    padding: 10px;
    border-bottom: 1px dotted #ff2;
    background: transparent;
    border-radius: 0;
    text-align: left;
}
.menu-bar ul li:hover .sub-menu-1 ul li:last-child{
    border-bottom:none;
}
.menu-bar ul li:hover .sub-menu-1 ul li a:hover{
    color: rgba(255,255,100, .3);
}
.sub-menu-2{
    display: none;
}
.hover-2:hover .sub-menu-2{
    position: absolute;
    display: block;
    margin-top: -40px;
    margin-left: 70px;
    background: greenyellow;
}