vant/packages/vant-css/src/cell-swipe.css

.van-cell-swipe {
  overflow: hidden;
  position: relative;

  &__wrapper,
  &__left,
  &__right {
    transition: transform .15s ease-in-out;
  }

  &__left,
  &__right {
    top: 0;
    height: 100%;
    position: absolute;
  }

  &__left {
    left: 0;
    transform: translate3d(-100%, 0, 0);
  }

  &__right {
    right: 0;
    transform: translate3d(100%, 0, 0);
  }
}