1 導航欄樣式

最終實現樣式：

通過一組ul，li標籤實現導航欄

<div class="sear-list">
    <ul>
        <li class="current"><span>全部搜尋</span></li>
        <li><span>圖書</span></li>
        <li><span>期刊論文</span></li>
        <li><span>學位論文</span></li>
        <li><span>標準</span></li>
        <li><span>紙本館藏</span></li>
        <li><span>外文資源發現</span></li>
        <li><span>資料庫導航</span></li>
    </ul>
</div>  
 

對應樣式為：

/* reset */
*{
    padding: 0;
    margin: 0;
    box-sizing: border-box;
}
ul,li{
    list-style: none;
}
/* 導航欄樣式 -start */
.sear-list{
    width: 1000px;
    height: 60px;
    background-color: #ccc;
    padding: 20px 0 0 10px;
    margin: 0 auto;
}
/*清除浮動*/
.sear-list ul::after{
    content: '';
    display: block;
    clear: both;
}
.sear-list ul li{
    min-width: 55px;
    float: left;
    padding: 0 10px;
    margin: 0 11px;
    line-height: 30px;
    height: 30px;
    background-color: #fff;
    text-align: center; 
    position: relative; 
    cursor: pointer;
}
/* 通過偽元素新增新增三角形 */
.sear-list ul li::before{
    content: '';
    display: inline-block;
    border-width: 0 0 30px 20px;
    border-color: #fff;
    border-left-color: transparent !important;
    border-style: solid;
    position: absolute;
    left: -20px;
}
.sear-list ul li::after{
    content: '';
    display: inline-block;
    border-width: 30px 20px 0 0;
    border-color: #fff;
    border-right-color: transparent !important;
    border-style: solid;
    position: absolute;
    right: -20px;
}
.current{
    background-color: red !important;
    color: #fff;
}
.current::before,.current::after{
    border-color: red !important;
}
/* 下方三角形 */
.current span::after{
    content: '';
    display: inline-block;
    border-top: 6px solid red;
    border-left: 6px solid transparent;
    border-right: 6px solid transparent;
    position: absolute;
    bottom: -6px;
    left: 50%;
    transform: translateX(-6px);
}
 

通過jQuery實現導航欄的點選效果，首先需要引入jQuery庫：

$(document).ready(function (){// ready 事件
    $(".sear-list ul li").each(function(index){//遍歷物件
        $(this).click(function(){//點選觸發事件
            $(".sear-list ul li").removeClass("current");//刪除當前元素的樣式
            $(".sear-list ul li").eq(index).addClass("current");//添加當前元素的樣式
        });
    });
});