$v-panel-shadow-style: $v-shadow-style !default;
$v-panel-border-width: $v-border-width !default;
$v-panel-border-radius: $v-border-radius !default;

$v-panel-caption-background-color: null !default;
$v-panel-caption-gradient-depth: $v-gradient-depth/4 !default;
$v-panel-caption-bevel-style: first($v-bevel-style) !default;
$v-panel-caption-bevel-depth: $v-bevel-depth !default;



@mixin valo-panel ($primary-stylename: v-panel) {

  .#{$primary-stylename} {
    @include valo-panel-style;
  }

  .#{$primary-stylename}-caption {
    @include valo-panel-caption-style;
  }

  .#{$primary-stylename}-content {
    @include box-sizing(border-box);
    width: 100%;
    height: 100%;
    @include valo-panel-adjust-content-margins;
  }

}



@function valo-panel-background-color ($context: $v-app-background-color) {
  $bg-color: lighten($context, 5%);
  @return $bg-color;
}


@function valo-panel-caption-background-color ($background-color) {
  @return $background-color or $v-app-background-color;
}


@function valo-panel-border-color ($background-color: $v-app-background-color) {
  $border-color: if(color-luminance($background-color) < color-luminance($v-app-background-color), $background-color, $v-app-background-color);
  $border-color: blend-darken($border-color, scale-color($border-color, $lightness: max(-30%, -$v-bevel-depth/2)));
  $border-color: scale-color($border-color, $saturation: -$v-bevel-depth/2);
  @return $border-color;
}


@mixin valo-panel-style {
  background: valo-panel-background-color();
  border-radius: $v-panel-border-radius;
  border: $v-panel-border-width solid valo-panel-border-color(valo-panel-background-color());
  box-shadow: valo-shadow($shadow-style: $v-panel-shadow-style);
}


@mixin valo-panel-caption-style ($background-color: $v-panel-caption-background-color) {
  @include box-sizing(border-box);
  padding: 0 round($v-unit-size/3);
  line-height: $v-unit-size;
  $_bg: valo-panel-caption-background-color($background-color);
  $_border-color: scale-color($_bg, $lightness: -$v-panel-caption-bevel-depth/2, $saturation: -$v-panel-caption-bevel-depth/2);
  border-bottom: $v-panel-border-width solid $_border-color;
  border-bottom-color: rgba($_border-color, .8);
  @include valo-gradient($color: $_bg, $depth: $v-panel-caption-gradient-depth);
  color: valo-font-color($_bg);
  font-weight: $v-caption-font-weight;
  font-size: $v-caption-font-size;
  box-shadow: valo-bevel($_bg, $bevel-style: $v-panel-caption-bevel-style, $bevel-depth: $v-panel-caption-bevel-depth, $gradient-depth: $v-panel-caption-gradient-depth);
}


@mixin valo-panel-well-style {
  $_bg: scale-color(adjust-color($v-app-background-color, $lightness: -2%), $saturation: -1.5%);
  background: $_bg;
  box-shadow: valo-shadow($shadow-style: (0 1px 0 0 v-hilite, join(inset, $v-panel-shadow-style)));
  border-radius: $v-border-radius;
  border: $v-border-width solid valo-panel-border-color(valo-panel-background-color());

  .v-panel-caption {
    background: transparent;
    box-shadow: none;
  }
}


@mixin valo-panel-borderless-style {
  background: transparent;
  border: none;
  box-shadow: none;

  .v-panel-caption {
    background: transparent;
    box-shadow: none;
  }
}


@mixin valo-panel-adjust-content-margins {
  > .v-margin-top {
    padding-top: round($v-unit-size/3);
  }

  > .v-margin-right {
    padding-right: round($v-unit-size/3);
  }

  > .v-margin-bottom {
    padding-bottom: round($v-unit-size/3);
  }

  > .v-margin-left {
    padding-left: round($v-unit-size/3);
  }
}