导航式显示

<!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">
    <title>导航式显示</title>
    <script src="jquery-3.6.0.js"></script>
    <script>
        $(function(){
            $("ul>li").eq(6).nextAll().css({//$("ul>li").eq(6)==$("ul>li:eq(从0开始)")。nth-child(从1开始),first,last,even(双数),odd(单)
                color : "red",
                fontWeight : "bold",
            })

            $("ul").children().eq(6).prevAll().css({//$("ul>li")==$("ul").children()
                color : "pink",
                fontFamily : "华文彩云",
            });
            $("#l9").parent().css({
                backgroundColor : "yellow",
            })
            $(".bb").children().mouseenter(function(){
                $(this).css({
                    backgroundColor : "green",
                    textAligh : "center",
                });
                $(this).siblings().css({
                    backgroundColor : "red",
                })
                var num = $(this).html();
                $(this).parent().next().html(num);
            })
        })
    </script>
    <style>
        .b{
            width: 960px;
            height: 400px;
            background-color: pink;
        }
        .bb{
            width: 960px;
            height: 60px;
            background-color: orange;
            text-align: center;
            line-height: 50px;
        }
        .bb>div{
            width: 116px;
            height: 56px;
            background-color: red;
            border: 2px solid black;
            float: left;
        }
    </style>
</head>
<body>
    <ul>
        <li>111</li>
        <li>222</li>
        <li>333</li>
        <li>444</li>
        <li>555</li>
        <li>666</li>
        <li>777</li>
        <li>888</li>
        <li id="l9">999</li>
    </ul>
    <div class="b">
        <div class="bb">
            <div>1</div>
            <div>2</div>
            <div>3</div>
            <div>4</div>
            <div>5</div>
            <div>6</div>
            <div>7</div>
            <div>8</div>
        </div>
        <div>鼠标放上面盒子</div>
    </div>
</body>
</html>