vant-weapp/packages/slider/index.less

@import '../common/style/var.less';

.van-slider {
  position: relative;
  border-radius: 999px;
  background-color: @gray-light;

  &__bar {
    position: relative;
    border-radius: inherit;
    background-color: @blue;
  }

  &__button {
    width: 20px;
    height: 20px;
    border-radius: 50%;
    background-color: @white;
    box-shadow: 0 1px 2px rgba(0, 0, 0, .5);

    &-wrapper {
      position: absolute;
      top: 50%;
      right: 0;
      transform: translate3d(50%, -50%, 0);
  
      /* use pseudo element to expand touch area */
      &::after {
        content: '';
        position: absolute;
        width: 200%;
        height: 200%;
        top: -50%;
        left: -50%;
      }
    }
  }

  &--disabled {
    opacity: .3;
  }
}