:after, :before {
    /* -webkit-box-sizing: border-box; */
    -moz-box-sizing: border-box;
    box-sizing: border-box;
}
/*.to-top{width:60px;height:60px;position:fixed;right:30px;bottom:-100px;opacity:0;-webkit-transition:all .2s;-moz-transition:all .2s;-o-transition:all .2s;transition:all .2s;text-align:center;background-color:#fff;border:3px solid #000;line-height:18px;font-size:15px; padding-top: 18px; text-transform:uppercase;cursor:pointer}*/