AdminLTE/scss/dark/bootstrap/forms/_form-range.scss

// Range

.form-range {
  // background-color: transparent;

  &:focus {
    &::-webkit-slider-thumb { box-shadow: $form-range-thumb-focus-box-shadow-alt; }
    &::-moz-range-thumb     { box-shadow: $form-range-thumb-focus-box-shadow-alt; }
  }

  &::-webkit-slider-thumb {
    @include gradient-bg($form-range-thumb-bg-alt);
    border: $form-range-thumb-border-alt;
    @include box-shadow($form-range-thumb-box-shadow-alt);

    &:active {
      @include gradient-bg($form-range-thumb-active-bg-alt);
    }
  }

  &::-webkit-slider-runnable-track {
    // color: transparent; // Why?
    background-color: $form-range-track-bg-alt;
    // border-color: transparent;
    @include box-shadow($form-range-track-box-shadow-alt);
  }

  &::-moz-range-thumb {
    @include gradient-bg($form-range-thumb-bg-alt);
    border: $form-range-thumb-border-alt;
    @include box-shadow($form-range-thumb-box-shadow-alt);

    &:active {
      @include gradient-bg($form-range-thumb-active-bg-alt);
    }
  }

  &::-moz-range-track {
    // color: transparent;
    background-color: $form-range-track-bg-alt;
    // border-color: transparent; // Firefox specific?
    @include box-shadow($form-range-track-box-shadow-alt);
  }

  &:disabled {
    pointer-events: none;

    &::-webkit-slider-thumb {
      background-color: $form-range-thumb-disabled-bg-alt;
    }

    &::-moz-range-thumb {
      background-color: $form-range-thumb-disabled-bg-alt;
    }
  }
}