JS下划线跟随tab选项卡

效果图

HTML

<div class="nav">
    <ul>
        <lidon(0)">翠翠</li>
        <lidon(1)">嗯嗯</li>
        <lidon(2)">小白</li>
        <lidon(3)">小沫</li>
        <lidon(4)">同同</li>
    </ul>
</div>

<div class="tiao">

    <div id="zhou" class="zhou" style="left: 0;">
        <div class="ww"></div>
    </div>
</div>

<div id="nei" class="nei">
    <ul>
        <li style="background-color:#e4007f; display: block;">最猪的BOSS</li>
        <li style="background-color:#687de8">最萌的BOSS</li>
        <li style="background-color:#2fb936">最蠢的BOSS</li>
        <li style="background-color:#4dd5d0">最萌的BOSS</li>
        <li style="background-color:#e24759">最帅的BOSS</li>
    </ul>

</div>

CSS

* {
	margin:0;
	margin:0;
	padding:0;
	list-style:none;
}
.nav {
	width:100%;
	height:50px;
}
.nav ul {
	width:600px;
	height:50px;
	margin:0 auto;
}
.nav ul li {
	width:120px;
	height:50px;
	font-weight:800;
	font-size:18px;
	color:#515151;
	line-height:50px;
	text-align:center;
	float:left;
	cursor:pointer;
}
.tiao {
	width:600px;
	height:5px;
	background-color:#515151;
	margin:0 auto;
	position:relative;
	top:0;
	left:0;
}
.zhou {
	width:120px;
	height:5px;
	background-color:red;
	position:absolute;
	top:0;
	left:0;
}
.ww {
	width:0px;
	border-width:8px;
	border-style:solid;
	border-color:rgba(250,0,255,0) rgba(250,0,255,0) red rgba(250,0,255,0);
	position:absolute;
	top:-16px;
	left:56px;
}
.nei {
	width:600px;
	height:300px;
	margin:0 auto;
}
.nei li {
	width:600px;
	height:300px;
	color:#fff;
	font-family:"微软雅黑";
	font-size:40px;
	text-align:center;
	line-height:300px;
	display:none;
	margin-top:10px;
}

JS

var k;
var kk = 0;

function don(gh) {
    if (kk == 0) {
        kk = 1
        var w1 = document.getElementById('zhou')
        var t = parseInt(w1.style.left)

        if (t < gh * 120) {
            k = window.setInterval(
                function() {
                    goright(gh * 120)
                }, 30

            )
        } else if (t > gh * 120) {
            k = window.setInterval(
                function() {
                    goleft(gh * 120)
                }, 30

            )
        } else {
            kk = 0
        }


        var w2 = document.getElementById('nei').getElementsByTagName('li')
        for (var i = 0; i < w2.length; i++) {
            w2[i].style.display = "none"
        }

        w2[gh].style.display = "block"

    }




}




//右移动
function goright(gh1) {
    var w1 = document.getElementById('zhou')
    var t = parseInt(w1.style.left)
    t += 20

    if (t >= gh1) {
        t = gh1
        window.clearInterval(k)
        kk = 0
    }
    w1.style.left = t + "px"
}


//左移动

function goleft(gh1) {
    var w1 = document.getElementById('zhou')
    var t = parseInt(w1.style.left)
    t -= 20
    //alert(t)
    if (t <= gh1) {
        t = gh1
        window.clearInterval(k)
        kk = 0
    }
    w1.style.left = t + "px"
}

提示： jQuery调用版本：1.11.3