$panel-margin ?= $block-spacing
$panel-item-border ?= 1px solid $border-light
$panel-radius ?= $radius-large
$panel-shadow ?= 0 0.5em 1em -0.125em rgba($scheme-invert, 0.1), 0 0px 0 1px rgba($scheme-invert, 0.02)

$panel-heading-background-color ?= $border-light
$panel-heading-color ?= $text-strong
$panel-heading-line-height ?= 1.25
$panel-heading-padding ?= 0.75em 1em
$panel-heading-radius ?= $radius
$panel-heading-size ?= 1.25em
$panel-heading-weight ?= $weight-bold

$panel-tabs-font-size ?= 0.875em
$panel-tab-border-bottom ?= 1px solid $border
$panel-tab-active-border-bottom-color ?= $link-active-border
$panel-tab-active-color ?= $link-active

$panel-list-item-color ?= $text
$panel-list-item-hover-color ?= $link

$panel-block-color ?= $text-strong
$panel-block-hover-background-color ?= $background
$panel-block-active-border-left-color ?= $link
$panel-block-active-color ?= $link-active
$panel-block-active-icon-color ?= $link

$panel-icon-color ?= $text-light
$panel-colors ?= $colors

.panel
  border-radius $panel-radius
  box-shadow $panel-shadow
  font-size $size-normal
  &:not(:last-child)
    margin-bottom $panel-margin
  // Colors
  for $name, $components in $panel-colors
    $color = $components['1']
    $color-invert = $components['2']
    &.is-{$name}
      .panel-heading
        background-color $color
        color $color-invert
      .panel-tabs a.is-active
        border-bottom-color $color
      .panel-block.is-active .panel-icon
        color $color

.panel-tabs,
.panel-block
  &:not(:last-child)
    border-bottom $panel-item-border

.panel-heading
  background-color $panel-heading-background-color
  border-radius $panel-radius $panel-radius 0 0
  color $panel-heading-color
  font-size $panel-heading-size
  font-weight $panel-heading-weight
  line-height $panel-heading-line-height
  padding $panel-heading-padding

.panel-tabs
  align-items flex-end
  display flex
  font-size $panel-tabs-font-size
  justify-content center
  a
    border-bottom $panel-tab-border-bottom
    margin-bottom -1px
    padding 0.5em
    // Modifiers
    &.is-active
      border-bottom-color $panel-tab-active-border-bottom-color
      color $panel-tab-active-color

.panel-list
  a
    color $panel-list-item-color
    &:hover
      color $panel-list-item-hover-color

.panel-block
  align-items center
  color $panel-block-color
  display flex
  justify-content flex-start
  padding 0.5em 0.75em
  input[type="checkbox"]
    ltr-property("margin", 0.75em)
  & > .control
    flex-grow 1
    flex-shrink 1
    width 100%
  &.is-wrapped
    flex-wrap wrap
  &.is-active
    border-left-color $panel-block-active-border-left-color
    color $panel-block-active-color
    .panel-icon
      color $panel-block-active-icon-color
  &:last-child
    border-bottom-left-radius $panel-radius
    border-bottom-right-radius $panel-radius

a.panel-block,
label.panel-block
  cursor pointer
  &:hover
    background-color $panel-block-hover-background-color

.panel-icon
  fa(14px, 1em)
  color $panel-icon-color
  ltr-property("margin", 0.75em)
  .fa
    font-size inherit
    line-height inherit