选中商品右下角三角形对勾实现

    .price-box.active {
      width: 151px;
      height: 160px;
      border: 2px solid #FF3333;
      position: relative;
      transition: all 0.5s ease;
      &::after {
        content: '✔';
        display: block;
        height: 0px;
        width: 0px;
        position: absolute;
        bottom: 0;
        right: 0;
        color:#fff;
        font-size: 14px;
        line-height: 18px;
        border: 18px solid;
        border-color: transparent #FF3333 #FF3333 transparent;;
      }