/**
 * delay
 */

.nth-child(@child, @start, @increment, @decrement, @rules) when (@child > 0) {
  .nth-child(@child - 1, @start, @increment, @decrement, @rules);
  &:nth-child(@{child}) {
    @rules();
  }
}

@animation-delay: { animation-delay: @start + ((@child - 1) * @increment) - ((@child - 1) * @decrement); };

@transition-delay: { transition-delay: @start + ((@child - 1) * @increment) - ((@child - 1) * @decrement); };

/**
 * custom
 */

// collapse

.collapse-height {
  overflow: hidden;
  height: 0;
  &:before {
    display: none;
    content: 'xt-collapse-height';
  }
}

.collapse-width {
  overflow: hidden;
  width: 0;
  &:after {
    display: none;
    content: 'xt-collapse-width';
  }
}

.collapse-reset {
  overflow: visible !important;
}