vant/packages/zanui-css/src/picker.css

@component-namespace zan {
  @b picker {
    overflow: hidden;

    @e toolbar {
      height: 40px;
    }

    @e columns {
      position: relative;
      overflow: hidden;

      @m 1 {
        .zan-picker-column {
          width: 100%;
        }
      }

      @m 2 {
        .zan-picker-column {
          width: 50%;
        }
      }

      @m 3 {
        .zan-picker-column {
          width: 33.333%;
        }
      }
    }
  }

  .zan-picker-center-highlight {
    box-sizing: border-box;
    position: absolute;
    left: 0;
    width: 100%;
    top: 50%;
    margin-top: -18px;
    pointer-events: none;
  }

  .zan-picker-center-highlight:before,
  .zan-picker-center-highlight:after {
    content: '';
    position: absolute;
    height: 1px;
    width: 100%;
    background-color: #eaeaea;
    display: block;
    zan-index: 15;
    transform: scaleY(0.5);
  }

  .zan-picker-center-highlight:before {
    left: 0;
    top: 0;
    bottom: auto;
    right: auto;
  }

  .zan-picker-center-highlight:after {
    left: 0;
    bottom: 0;
    right: auto;
    top: auto;
  }

  @b picker-column {
    font-size: 18px;
    overflow: hidden;
    position: relative;
    max-height: 100%;
    float: left;
    text-align: center;

    @e item {
      height: 44px;
      line-height: 44px;
      padding: 0 10px;
      white-space: nowrap;
      position: relative;
      overflow: hidden;
      text-overflow: ellipsis;
      color: #707274;
      left: 0;
      top: 0;
      width: 100%;
      box-sizing: border-box;
      transition-duration: .3s;
      backface-visibility: hidden;

      @m selected {
        color: #000;
        transform: translate3d(0, 0, 0) rotateX(0);
      }
    }
  }

  .picker-column-wrapper {
    transition-duration: 0.3s;
    transition-timing-function: ease-out;
    backface-visibility: hidden;
  }

  .picker-column-wrapper.dragging,
  .picker-column-wrapper.dragging .picker-item {
    transition-duration: 0s;
  }
}