tabler.tabler/core/scss/ui/_accordion.scss

.accordion {
  --#{$prefix}accordion-color: var(--#{$prefix}body-color);
  --#{$prefix}accordion-border-color: var(--#{$prefix}border-color);
  --#{$prefix}accordion-border-radius: #{$accordion-border-radius};
  --#{$prefix}accordion-inner-border-radius: #{$accordion-inner-border-radius};
  --#{$prefix}accordion-padding-x: #{$accordion-body-padding-x};
  --#{$prefix}accordion-gap: 0;
  --#{$prefix}accordion-active-color: #{$accordion-button-active-color};
  --#{$prefix}accordion-btn-color: var(--#{$prefix}accordion-color);
  --#{$prefix}accordion-btn-bg: #{$accordion-button-bg};
  --#{$prefix}accordion-btn-toggle-width: 1.25rem;
  --#{$prefix}accordion-btn-padding-x: var(--#{$prefix}accordion-padding-x);
  --#{$prefix}accordion-btn-padding-y: #{$accordion-button-padding-y};
  --#{$prefix}accordion-btn-font-weight: var(--#{$prefix}font-weight-medium);
  --#{$prefix}accordion-body-padding-x: var(--#{$prefix}accordion-padding-x);
  --#{$prefix}accordion-body-padding-y: #{$accordion-body-padding-y};

  display: flex;
  flex-direction: column;
  gap: var(--#{$prefix}accordion-gap);
}

.accordion-button {
  position: relative;
  display: flex;
  align-items: center;
  width: 100%;
  padding: var(--#{$prefix}accordion-btn-padding-y) var(--#{$prefix}accordion-padding-x);
  color: inherit;
  text-align: inherit;
  background-color: transparent;
  border: 0;
  font-size: inherit;
  font-weight: var(--#{$prefix}accordion-btn-font-weight);
  gap: .75rem;

  &:not(.collapsed) {
    border-bottom-color: transparent;
    box-shadow: none;
    color: var(--#{$prefix}accordion-active-color);
  }
}

.accordion-header {
  margin: 0;
  position: relative;
  display: flex;
  gap: 1rem;
  align-items: center;
  width: 100%;
  color: var(--#{$prefix}accordion-btn-color);
  text-align: left;
  background-color: transparent;
  border: 0;
  overflow-anchor: none;
  transition: transform $transition-time;

  &:hover {
    z-index: 2;
  }

  &:focus {
    z-index: 3;
    outline: 0;
    box-shadow: var(--#{$prefix}accordion-btn-focus-box-shadow);

    &:not(:focus-visible) {
      outline: none;
      box-shadow: none;
    }
  }
}

.accordion-button-icon {
  color: var(--#{$prefix}secondary);
}

.accordion-button-toggle {
  display: flex;
  line-height: 1;
  transition: $transition-time transform;
  margin-left: auto;
  margin-right: 0;
  color: var(--#{$prefix}secondary);
  width: var(--#{$prefix}accordion-btn-toggle-width);
  height: var(--#{$prefix}accordion-btn-toggle-width);

  .accordion-button:not(.collapsed) & {
    transform: rotate(-180deg);
    color: var(--#{$prefix}accordion-active-color);
  }

  path {
    transition: $transition-time opacity;
  }
}

.accordion-button-toggle-plus {
  .accordion-button:not(.collapsed) & {
    path:first-child {
      opacity: 0;
    }
  } 
}

.accordion-item {
  color: var(--#{$prefix}accordion-color);
  border: var(--#{$prefix}border-width) solid var(--#{$prefix}accordion-border-color);

  &:first-of-type {
    @include border-top-radius(var(--#{$prefix}accordion-border-radius));

    > .accordion-header {
      @include border-top-radius(var(--#{$prefix}accordion-inner-border-radius));
    }
  }

  &:not(:first-of-type) {
    border-top: 0;
  }

  &:last-of-type {
    @include border-bottom-radius(var(--#{$prefix}accordion-border-radius));

    > .accordion-header {
      &.collapsed {
        @include border-bottom-radius(var(--#{$prefix}accordion-inner-border-radius));
      }
    }

    > .accordion-collapse {
      @include border-bottom-radius(var(--#{$prefix}accordion-border-radius));
    }
  }
}

.accordion-body {
  color: var(--#{$prefix}secondary);
  padding: 0 var(--#{$prefix}accordion-body-padding-x) var(--#{$prefix}accordion-body-padding-y);
}

.accordion-flush {
  > .accordion-item {
    border-right: 0;
    border-left: 0;
    @include border-radius(0);

    &:first-child {
      border-top: 0;
    }
    &:last-child {
      border-bottom: 0;
    }

    > .accordion-collapse,
    > .accordion-header .accordion-button,
    > .accordion-header .accordion-button.collapsed {
      @include border-radius(0);
    }
  }
}

.accordion-tabs {
  --#{$prefix}accordion-gap: 0.75rem;

  > .accordion-item {
    border: var(--#{$prefix}border-width) solid var(--#{$prefix}accordion-border-color);
    border-radius: var(--#{$prefix}accordion-border-radius);
  }
}

.accordion-inverted {
  .accordion-button-toggle {
    order: -1;
    margin-left: 0;
  }
}