// 设置左侧箭头盒子start
      .back_wrap {
        margin-top: 13px;
        width: 38px;
        height: 30px;
        border: 1px solid #dcdfe6;
        position: relative;
        margin-right: 15px;
        cursor:pointer;//鼠标经过变小手
        // 设置箭头
        .back {
          width: 10px;
          height: 10px;
          position: absolute;
          top: 50%;
          left: 60%;
          transform: translate(-50%, -50%) rotate(-40deg);
          border-top: 1px solid #c3c8d6;
          border-left: 1px solid #c3c8d6;
        }
      }
      // 设置左侧箭头盒子end

                    <div class="back_wrap">
                      <i class="back"></i>
                    </div>