CSS3实现手机页面1px边框（发丝边框）

1px边框.css

        .panel{
            height: 48vmin;
            width: 50%;
            margin-top: 0px;
            margin-bottom: 0px;
            border-radius:0px;
            color: #ffffff;
            position: relative;
            border: none;
            overflow:hidden;
        }
        .panel:after
        {
            content: '';
            position: absolute;
            top: 0;
            left: 0;
            border: 1px solid #efefef;
            border-bottom: none;
            border-left: none;
            -webkit-box-sizing: border-box;
            box-sizing: border-box;
            width: 200%;
            height: 200%;
            -webkit-transform: scale(0.5);
            transform: scale(0.5);
            -webkit-transform-origin: left top;
            transform-origin: left top;
        }