css制作下拉框（不用js）

<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <link rel="stylesheet" href="xiala.css">
    <title>Document</title>
</head>
<body>
    <div class="f1 fl">
        <ul>
            <li class="f3">湖人队
                <div class="f2">
                    <ul>
                        <li>詹姆斯</li>
                        <li>戴维斯</li>
                        <li>格林</li>
                    </ul>
                </div>
            </li>
            <li>快船队</li>
            <li>76队</li>
            <li>火箭队</li>
            <li>凯尔特人队</li>
        </ul>
    </div>
     
</body>
</html>

*{
    margin: 0px;
    padding: 0px;
}
body{
    font-size: 14px;
    font-family: "Microsoft Yahei";
    color:#000;
}

.wrap{
    margin: 0 auto;
}
.fl{
    float:left;
}
.fr{
    float:right;
}
.cl::after{
    content: "";
    display: block;
    clear: both;
}
ul,li{
    list-style-type: none;
}
.f1{
    width:700px;
    margin-left: 350px;
}
.f1 ul li{
    width: 125px;
    height: 50px;
    line-height: 50px;
    color: #fff;
    background: green;
    text-align: center;
    float: left;
    cursor: pointer;
    position: relative;
}
.f2{
    width: 125px;
    position: absolute;
    height: 300px;
    background-color: red;
    top: 50px;
    cursor: pointer;
    display: none;
}
.f2 ul li{
    height: 100px;
    line-height: 100px;
    text-align: center;
}
.f2 ul li:hover{
    background-color: red;
    color: #fff;
}
.f1 ul li:hover .f2 {
   display: block;
}