样式效果如下，点击商品详情 添加样式active
代码
<!doctype html>
<html lang="en">
<head>
<meta charset="UTF-8">
<meta name="Generator" content="EditPlus®">
<meta name="Author" content="">
<meta name="Keywords" content="">
<meta name="Description" content="">
<title>Document</title>
<style>
.P_nav {
top: 0;
position: absolute;
width: 888px;
height: 48px;
border: 1px solid #eaeaea;
background-color: #f8f8f8;
}
.P_nav .active {
color: #d41c44;
background-color: #fff;
font-weight: bold;
}
.P_nav .active i {
position: absolute;
height: 45px;
line-height: 0;
width: 100%;
top: -1px;
left: 0;
border-top: 4px solid #d41c44;
border-bottom: 1px solid #fff;
}
.P_nav span {
position: relative;
display: inline-block;
border-right: 1px solid #eaeaea;
width: 159px;
color: #333;
text-align: center;
height: 48px;
line-height: 48px;
font-size: 16px;
cursor: pointer;
vertical-align: top;
}
a, a:hover {
color: #51b8f1;
}
.goods_parameter {
padding: 15px 0 0 20px;
overflow: hidden;
*zoom: 1;
position: relative;
border-left: 1px solid #eaeaea;
border-right: 1px solid #eaeaea;
border-bottom: 1px solid #eaeaea;
}
ol, ul {
list-style: none;
}
.goods_parameter li {
float: left;
width: 40%;
height: 18px;
line-height: 18px;
font-size: 12px;
color: #333;
padding: 5px 0 0 0;
margin-right: 3%;
}
.ellipsis {
overflow: hidden;
-o-text-overflow: ellipsis;
text-overflow: ellipsis;
white-space: nowrap;
word-break: keep-all;
word-wrap: normal;
}
.P_nav span em {
color: #d41c44;
font-style: normal;
}
</style>
</head>
<body>
<span>11111</span>
<div class="P_nav j-nav" style="">
<span id="s1" class="j-imagedetailTab j-navtab active" style="cursor:pointer" onclick="showProductInfo(1)">商品详情<i></i></span>
<span id="s2" class="j-userratingTab j-navtab" style="cursor:pointer" onclick="showProductInfo(2)">用户评价<em> <b id="commentCounts" class="commentCount v1 v0">2264</b> </em><i></i></span>
</div>
<div id="goodsDetail" class="j-imagedetail j-navinfo">
<ul class="goods_parameter">
<li title="5.8 英寸" class="ellipsis">屏幕尺寸：5.8 英寸</li>
<li title="1200万像素" class="ellipsis">后置摄像头像素：1200万像素</li>
<li title="A11+M11 运动协处理器" class="ellipsis">CPU型号：A11+M11 运动协处理器</li>
<li title="5.6英寸及以上" class="ellipsis">屏幕尺寸：5.6英寸及以上</li>
<li title="64GB" class="ellipsis">机身内存：64GB</li>
<li title="全网通" class="ellipsis">网络类型：全网通</li>
<li title="iPhone X" class="ellipsis">型号(宣传型号)：iPhone X</li>
<li title="2017.09.22" class="ellipsis">上市时间：2017.09.22</li>
</ul>
</div>
<div id="userRating" class="goods_parameter">
<br />
<br />
212121323234
<br />
212121323234
</div>
<script>
function showProductInfo(a) {
if (a == 1) {
addClass(document.getElementById('s1'), 'active');
removeClass(document.getElementById('s2'), 'active');
document.getElementById('goodsDetail').style.display = "";
document.getElementById('userRating').style.display = "none";
}
else {
addClass(document.getElementById('s2'), 'active');
removeClass(document.getElementById('s1'), 'active');
document.getElementById('goodsDetail').style.display = "none";
document.getElementById('userRating').style.display = "";
}
}
function hasClass(ele, cls) {
cls = cls || '';
if (cls.replace(/\s/g, '').length == 0) return false; //当cls没有参数时，返回false
return new RegExp(' ' + cls + ' ').test(' ' + ele.className + ' ');
}
function addClass(ele, cls) {
if (!hasClass(ele, cls)) {
ele.className = ele.className == '' ? cls : ele.className + ' ' + cls;
}
}
function removeClass(ele, cls) {
if (hasClass(ele, cls)) {
var newClass = ' ' + ele.className.replace(/[\t\r\n]/g, '') + ' ';
while (newClass.indexOf(' ' + cls + ' ') >= 0) {
newClass = newClass.replace(' ' + cls + ' ', ' ');
}
ele.className = newClass.replace(/^\s+|\s+$/g, '');
}
}
</script>
</body>
</html>