background-image制作圆点边框

1.实现图
2.代码实现
<!DOCTYPE html>
<html>
    <head>
        <meta charset="utf-8">
        <title></title>
        <style type="text/css">
            .box {
                width:50%;
                height: 300px;
                margin: 0 auto;
            }
            .box2 {
                position: relative;
                width: 100%;
                height: 300px;
                overflow: hidden;
                background-color: #eee;
            }
            .box2:before{
                content: '';
                position: absolute;
                top: 0;
                left: 0px;
                display: block;
                width: 100%;
                height: 20px;
                background-size: 40px 40px;
                background-color: #D96F2B;
                background-position: 100% 50%;
                background-image: radial-gradient(closest-side, transparent 60%,  #f0f0f0 25%), radial-gradient(closest-side, transparent 60%,  #f0f0f0 25%);
            }
        </style>
    </head>
    <body>
        <div class='box'>
            <div class='box2'></div>
        </div>
    </body>
</html>