<style>
            *{
                margin: 0;
                padding: 0;
            }
            body{
                background: whitesmoke;
            }
            ul{
                list-style: none;
            }
            .content{
                margin-right:auto;
                margin-left: auto;
                margin-top: 50px;
                width: 1000px;
                height: 350px;
                border: 1px solid #999999;
                border-radius: 10px;
                overflow: hidden;
            }
            .content>h2{
                width: 100%;
                height: 20%;
                box-sizing: border-box;
                border-bottom: 1px solid silver;
                line-height: 70px;
                font-size: 18px;
                text-indent: 2em;
                font-weight: normal;
            }
            .item{
                width: 100%;
                height: 80%;
            }
            .item>li{
                width: 25%;
                height: 100%;
                float: left;
                background: greenyellow;
                                position: relative;
            }
            .bf:before{
                content: '';
                width: 1px;
                height: 100%;
                display: block;
                z-index: 100;
                background:yellow;
                                position:absolute;
            }
        </style>

<div class="content">
            <h2>标题</h2>
            <ul class="item">
                <li></li>
                <li class="bf"></li>
                <li class="bf"></li>
                <li class="bf"></li>
            </ul>
            
        </div>