IT61/it61-rails

.switch {
  @include clearfix;

  $switch-width: 30px;
  $switch-padding: 2px;
  $switch-height: 13px;
  $knob-size: $switch-height - ($switch-padding * 2) + 8px;
  $knob-width: $knob-size;

  $knob-position: -2px 0 0 -5px;
  $knob-after-position: $switch-width - $knob-width - ($switch-padding * 2) + 1px + 5px;

  cursor: pointer;
  display: inline-block;
  position: relative;
  top: 4px;
  margin-right: 15px;
  span {
    line-height: $switch-height * 2;
    color: #333;
    margin-left: 15px;
  }

  input {
    display: none;

    + .checkbox {
      @include size($switch-width, $switch-height);
      background-color: #b0afaf;
      cursor: pointer;
      position: relative;
      width: $switch-width;
      float: left;
      margin-top: 6px;
      z-index: 0;
      border-radius: 20px;

      &::before {
        @include position(absolute, $switch-padding 0 0 $switch-padding);
        content: "";
        width: $switch-width - ($switch-padding * 2);
        z-index: 1;
      }

      &::after {
        @include position(absolute, $knob-position);
        @include size($knob-size);
        background-color: #f1f1f1;
        box-shadow: 1px 1px 7px rgba(0, 0, 0, 0.39);
        content: "";
        transition: all 0.3s ease;
        z-index: 2;
        border-radius: 100%;
      }
    }

    &:checked {
      + .checkbox {
        background-color: #99cfff;

        &::after {
          left: $knob-after-position;
          background-color: #4ba8fb;
        }
      }
    }
  }
}