最简单的Tab切换

HTML

<div class="main">
     <div class="btn">
     	 <!-- Tab标题 -->
         <span class="active spanList">课程介绍</span>
         <span class="spanList">用户故事</span>
         <span class="spanList">常见问题</span>
         <span class="spanList">电影列表</span>
     </div>
    <div class="context">
         <!-- Tab内容 -->
         <div class="con"> 第一个<br/></div>
         <div class="con">第二个<br /> </div>
         <div class="con">第三个<br /> </div>
         <div class="con">第四个<br /> </div>
     </div>
 </div>

CSS

.main {
    width: 100%;
    /* background-color: green; */
}
.btn{ 
    width: 100%;
    height: 1.2rem;
    display: flex;
    justify-content: space-around;
    box-shadow: 0 0.04rem 0 rgba(0,55,88,.1);  
}
.spanList{ 
    font-family: PingFang-SC-Medium;
    font-size: 0.30rem;
    color: #3f3f3f; 
    text-align: center;
    line-height: 1.2rem;
    display:inline-block;
    position: relative;
    letter-spacing: 0.005rem;
    font-weight: 400;
}
.active{
    font-family: PingFang-SC-Bold;
    font-size: 0.48rem;
    font-weight: 600;
    color: #3f3f3f; 
    text-align: center;
    line-height: 1.2rem;
    letter-spacing: 0.005rem;
    display:inline-block;
}
.active::after{
    position: absolute;
    left: 0.48rem;
    top: 1rem;
    content:""; 
    width: 0.8rem;
    height: 0.08rem;
    background-color: #0FA2F9;
    border-radius: 0.04rem;
}
.context{
    width: 100%;
    float: left;
}
.con { 
    display:none; 
    width: 7.5rem;
    margin-top: 0.8rem;
}

JS切换(首先要引入jquery)

$(".con").eq(0).show();
$(".btn span").click(function(){
    var num =$(".btn span").index(this);
    $(".con").hide();
    $(".con").eq(num).show();
    $(this).attr("class","active spanList");
    $(this).siblings().attr("class","spanList");
})

效果展示：