4dkankan-components/packages/theme-chalk/scss/components/_size-animation.scss

.ui-size-animation {

  &.height {
    overflow: hidden;
  }

  &:not(.ready) {
    opacity: 0;
  }
  &.ready {
    transition: max-height .2s ease;
  }

  &.scale {
    transform-origin: center top;
    transform: scaleY(0); 

    &.show {
      transform: scaleY(1); 
    }

    &.ready {
      transition: max-height .2s ease,
        transform .2s ease;
    }
  }

}