//
// Panel Variables
//

// We use these to control the background and border styles
$panel-bg:              darken(#fff, 5%) !default;
$panel-border-style:    solid !default;
$panel-border-size:     1px !default;

// We use this % to control how much we darken things on hover
$panel-function-factor: 10% !default;
$panel-border-color:    darken($panel-bg, $panel-function-factor) !default;

// We use these to set default inner padding and bottom margin
$panel-margin-bottom:   emCalc(20px) !default;
$panel-padding:         emCalc(20px) !default;

// We use these to set default font colors
$panel-font-color:      #333 !default;
$panel-font-color-alt:  #fff !default;


//
// Panel Mixins
//

// We use this mixin to create panels.
@mixin panel($bg:$panel-bg, $padding:$panel-padding) {

  @if $bg {
    $bg-lightness: lightness($bg);

    border-style: $panel-border-style;
    border-width: $panel-border-size;
    border-color: darken($bg, $panel-function-factor);
    margin-bottom: $panel-margin-bottom;
    padding: $padding;

    background: $bg;

    // We set the font color based on the darkness of the bg.
    @if $bg-lightness >= 50% and $bg == blue { h1,h2,h3,h4,h5,h6,p { color: $panel-font-color-alt; } }
    @else if $bg-lightness >= 50%            { h1,h2,h3,h4,h5,h6,p { color: $panel-font-color; } }
    @else                                    { h1,h2,h3,h4,h5,h6,p { color: $panel-font-color-alt; } }

    // Respect the padding, fool.
    &>:first-child { margin-top: 0; }
    &>:last-child { margin-bottom: 0; }

    // reset header line-heights for panels
    h1,h2,h3,h4,h5,h6 {
      line-height: 1; margin-bottom: emCalc(20px) / 2;
      &.subheader { line-height: 1.4; }
    }
  }
}

// Only include these classes if the option exists
@if $include-html-panel-classes {

  /* Panels */
  .panel { @include panel;

    &.callout {
      @include panel($primary-color);
      @include inset-shadow($active:false);
    }

    &.radius {
      @include panel($bg:false);
      @include radius;
    }

  }

}