二级导航的做法

效果：

html的写法：

<!--导航-->
<header>
    <nav>
        <ul>
            <li><a href="index.html"><img src="../img/header_footer/logo.png" alt=""/></a></li>
            <li>
                <a href="">成都</a>
                <img src="../img/header_footer/xiasanjiao_03.gif" alt=""/>
                <ul>
                    <li><a href="">上海</a></li>
                    <li><a href="">北京</a></li>
                    <li><a href="">天津</a></li>
                    <li><a href="">广州</a></li>
                    <li><a href="">武汉</a></li>
                </ul>
            </li>
            <li class="daohang"><a href="index.html">首页</a></li>
            <li class="daohang"><a href="movies.html">电影</a></li>
            <li class="daohang"><a href="movies_list.html">榜单</a></li>
            <li class="daohang"><a href="news.html">热点</a></li>
            <li>
                <form action="#" method="post">
                    <input type="text" placeholder="找影视剧、影人、影院"/>
                    <i></i>
                </form>
            </li>
            <li>
                <a href=""><img src="../img/header_footer/login.png" alt=""/></a>
                <img src="../img/header_footer/xiasanjiao_03.gif" alt=""/>
                <ul>
                    <li><a href="landing.html">登录</a></li>
                    <li><a href="zhuce.html">注册</a></li>
                </ul>
            </li>
        </ul>
    </nav>
</header>

css写法：

/*导航header*/
a{
    text-decoration: none;
    color: black;
}
img{
    opacity: 0.9;
}
img:hover{
    opacity: 1;
}
body>header{
    width: 100%;
    position: fixed;
    top: 0;
    margin: 0 auto;
    background-color: white;
    z-index: 999;
    outline: 1px solid black;
}
body>header>nav{
    width: 1200px;
    margin: 0 auto;
}
body>header>nav>ul{
    width: 1200px;
    height: 80px;
    display: flex;
    align-items: center;
    font-size: 18px;
}

/*二级导航header*/

body>header>nav>ul>li>ul>li{
    width: 80px;
    height: 30px;
    padding: 5px 0;
    outline: 1px solid white;
    text-align: center;
    line-height: 30px;
}
body>header>nav>ul>li>ul>li:hover a{
    color: red;
}
body>header>nav>ul>li:nth-of-type(2)>ul{
    display: none;
    position: absolute;
    left: -8px;
    top: 82px;
}
body>header>nav>ul>li:nth-of-type(2){
    width: 76px;
    height: 80px;
    margin-left: 20px;
    margin-right: 50px;
    position: relative;
    line-height: 80px;
}
body>header>nav>ul>li:nth-of-type(8){
    height: 80px;
    line-height: 80px;
    position: relative;
}
body>header>nav>ul>li:nth-of-type(8)>ul{
    position: absolute;
    display: none;
    left: -9px;
    top: 82px;
}
body>header>nav>ul>li:hover>ul{
    display: block;
}
body>header>nav>ul>li:nth-of-type(2):hover img{
    transform: rotate(180deg);
}
body>header>nav>ul>li:nth-of-type(8):hover>img{
    transform: rotate(180deg);
}
.daohang{
    width: 80px;
    height: 80px;
    line-height: 80px;
    text-align: center;
}
.daohang:hover{
    background-color: red;
}
.daohang:hover a{
    color: white;
}
body>header>nav>ul>li:nth-of-type(7) input{
    width: 200px;
    height: 38px;
    margin-left: 245px;
    margin-right: 20px;
    position: relative;
    border-radius: 60px;
    border: 1px solid lightgray;
    outline: none;
    padding: 0 40px 0 20px;
}
body>header i{
    background-image: url("../img/header_footer/search.png");
    display: inline-block;
    height: 40px;
    width: 40px;
    position: absolute;
    left: 1150px;
    top: 19px;
}
body>header i{
    animation: shousuo linear 8s infinite;
}
@keyframes shousuo {
    100%{
        transform: rotate(360deg);
    }
}