tabler.tabler/core/scss/ui/_switch-icon.scss

.switch-icon {
  display: inline-block;
  line-height: 1;
  border: 0;
  padding: 0;
  background: transparent;
  width: $icon-size;
  height: $icon-size;
  vertical-align: bottom;
  position: relative;
  cursor: pointer;

  &.disabled {
    pointer-events: none;
    opacity: $btn-disabled-opacity;
  }

  &:focus {
    outline: none;
  }

  svg {
    display: block;
    width: 100%;
    height: 100%;
  }

  .switch-icon-a,
  .switch-icon-b {
    display: block;
    width: 100%;
    height: 100%;
  }

  .switch-icon-a {
    opacity: 1;
  }

  .switch-icon-b {
    position: absolute;
    top: 0;
    left: 0;
    opacity: 0;
  }

  &.active {
    .switch-icon-a {
      opacity: 0;
    }

    .switch-icon-b {
      opacity: 1;
    }
  }
}

// Fade variant
.switch-icon-fade {
  .switch-icon-a,
  .switch-icon-b {
    @include transition(opacity .5s);
  }
}

// Scale variant
.switch-icon-scale {
  .switch-icon-a,
  .switch-icon-b {
    @include transition(opacity .5s, transform .0s .5s);
  }

  .switch-icon-b {
    transform: scale(1.5);
  }

  &.active {
    .switch-icon-a,
    .switch-icon-b {
      @include transition(opacity .0s, transform .5s);
    }

    .switch-icon-b {
      transform: scale(1);
    }
  }
}

// Flip variant
.switch-icon-flip {
  perspective: 10em;

  .switch-icon-a,
  .switch-icon-b {
    backface-visibility: hidden;
    transform-style: preserve-3d;
    @include transition(opacity 0s .2s, transform .4s ease-in-out);
  }

  .switch-icon-a {
    opacity: 1;
    transform: rotateY(0deg);
  }

  .switch-icon-b {
    opacity: 1;
    transform: rotateY(-180deg);
  }

  &.active {
    .switch-icon-a {
      opacity: 1;
      transform: rotateY(180deg);
    }

    .switch-icon-b {
      opacity: 1;
      transform: rotateY(0deg);
    }
  }
}

// Slide variant
.switch-icon-slide-up,
.switch-icon-slide-left,
.switch-icon-slide-start,
.switch-icon-slide-right,
.switch-icon-slide-end,
.switch-icon-slide-down {
  overflow: hidden;

  .switch-icon-a,
  .switch-icon-b {
    @include transition(opacity $transition-time, transform $transition-time);
  }

  .switch-icon-a {
    transform: translateY(0);
  }

  .switch-icon-b {
    transform: translateY(100%);
  }

  &.active {
    .switch-icon-a {
      transform: translateY(-100%);
    }

    .switch-icon-b {
      transform: translateY(0);
    }
  }
}

.switch-icon-slide-left,
.switch-icon-slide-start {
  .switch-icon-a {
    transform: translateX(0);
  }

  .switch-icon-b {
    transform: translateX(100%);
  }

  &.active {
    .switch-icon-a {
      transform: translateX(-100%);
    }

    .switch-icon-b {
      transform: translateX(0);
    }
  }
}

.switch-icon-slide-right,
.switch-icon-slide-end {
  .switch-icon-a {
    transform: translateX(0);
  }

  .switch-icon-b {
    transform: translateX(-100%);
  }

  &.active {
    .switch-icon-a {
      transform: translateX(100%);
    }

    .switch-icon-b {
      transform: translateX(0);
    }
  }
}

.switch-icon-slide-down {
  .switch-icon-a {
    transform: translateY(0);
  }

  .switch-icon-b {
    transform: translateY(-100%);
  }

  &.active {
    .switch-icon-a {
      transform: translateY(100%);
    }

    .switch-icon-b {
      transform: translateY(0);
    }
  }
}