弹框小三角

.f-list-header-plate:before {
    content: "";
    position: absolute;
    left: 63px;
    top: -5px;
    display: block;
    width: 10px;
    height: 10px;
    z-index: 1;
    background-color: #fff;
    border: 1px solid #ebebeb;
    -webkit-transform: rotate(45deg);
    -moz-transform: rotate(45deg);
    -ms-transform: rotate(45deg);
    transform: rotate(45deg);
    border-color: #ebebeb transparent transparent #ebebeb;
  }