<style>

   *{margin: 0;padding: 0}
   .wrap{
       
   }
   .container{
       width: 100%;
       overflow: hidden;
       /* height: 400px; */
       background: red;
       position: relative;
   }
   .box{width: 125%;
       height: auto;
       display: flex;
        align-items: center;
        position: relative;
        left: 0;
       }
    .box li{
        width: 20%;
        float: left;
        list-style: none;
        -webkit-transition: width 0.5s, height 0.5s, margin 0.5s;
        position: relative;
    }
    .box video {
        width: 100%;
        height: 100%;
    }
    .box li div {
        position: absolute;
        top: 0;
        bottom: 0;
        left: 0;
        right: 0;
    }
    .box li div img {
        width: 100%;
        height: 100%;
    }
    /* .box li:nth-child(2){
        height: 360px;
        margin: 0 1%;
    } */
    .goLeft, .goRight {
        position: absolute;
        width: 28px;
        height: 52px;
        top: 50%;
        transform: translate(0,-50%);
        cursor: pointer;
        border: none;
        outline: none;
        line-height: 52px;
    }
    .goLeft {
        left: 20%;
    }
    .goRight {
        right: 20%;
    }
    .box li>p {
        margin: 0;
        color: #fff;
        position: absolute;
        top: 50%;
        left: 50%;
        transform: translate(-50%,-50%);
        text-align: center;
    }
    .box li>p>span {
        display: inline-block;
        width: 100px;
        height: 100px;
        background: url(play.png);
    }
    .ddd{
        width: 100%;
        height: 360px;
        display: flex;
align-items: center;
position: relative;
    }
    .dd-2{
        width: 20%;
        background: yellow;
    }
    .aa{
        width: 100%;
    }
</style>

<div class="wrap">

    <div class="container">
        <ul class="box">
            <li class="video1">
                <video></video>
                <div><img src="3.jpg" alt="">1</div>
            </li>
            <li class="video2">
                <video></video>
                <div><img src="3.jpg" alt="">2</div>
            </li>
            <li class="video3">
                <video></video>
                <div><img src="3.jpg" alt="">3</div>
            </li>
            <li class="video4">
                <video></video>
                <div><img src="3.jpg" alt="">4</div>
            </li>
        </ul>
        <button onclick="moveRight()" class="goLeft btn">左</button> 
        <button onclick="moveLeft()" class="goRight btn">右</button>
    </div>
    <div class="ddd">
        <div class="dd-2"><div class="aa">aaa</div><div class="bb">vvvv</div></div>
    </div>
</div>

$(function(){
    $('.box>li:nth(1)').css({ width: '36%', margin: '0 2%' })
    $('.box>li:nth(1)').append('视频主题')
    
})
$(window).resize(function () {          //当浏览器大小变化时
    $('.box').css('height', 'auto')
})
function moveLeft(){
        var height = $('.box>li:nth(1)').height()
        $('.box').css('height', height)
        $('.box>li').css({ width: '20%', margin: '0 0%' })
        $('.box>li:nth(2)').css({ width: '36%', margin: '0 2%' })
        $('.box').animate({
            left: '-25%'
        }, 400, function () {
            // 把第一个子元素移到最后，并且设置left=0
            $(".box").append($('.box>li:nth(0)')[0]);
            $(".dd-2").append($('.aa')[0]);
            $(".aa").append('ccc');
            $('.box').css('left', 0);
            $(".btn").attr("disabled", false);
            $('.box>li:nth(1)').append('视频主题')

        });
    }
    function moveRight(){
        $('.box>li').css({ width: '20%', margin: '0 0%' })
        $('.box>li:nth(0)').css({ width: '36%', margin: '0 2%' })
        var height = $('.box>li:nth(1)').height()
        $('.box').css('height', height)
        $(".box").prepend($('.box>li:nth(3)')[0]);
        
        $('.box').css('left', '-20%');
        $('.box').animate({
            left: 0
        }, 400, function () {
            $(".btn").attr("disabled", false);
            $('.box>li:nth(1)').append('视频主题')
        });
    }