gtk2/gtk/theme/Adwaita/_common.scss

@function gtkalpha($c,$a) {
  @return unquote("alpha(#{$c},#{$a})");
}

$ease-out-quad: cubic-bezier(0.25, 0.46, 0.45, 0.94);
$asset_suffix: if($variant=='dark', '-dark', '');

* {
  padding: 0;
  -GtkToolButton-icon-spacing: 4;
  -GtkTextView-error-underline-color: $error_color;

  // The size for scrollbars. The slider is 2px smaller, but we keep it
  // up so that the whole area is sensitive to button presses for the
  // slider. The stepper button is larger in both directions, the slider
  // only in the width

  -GtkScrolledWindow-scrollbar-spacing: 0;
  -GtkScrolledWindow-scrollbars-within-bevel: 1;

  -GtkToolItemGroup-expander-size: 11;
  -GtkTreeView-expander-size: 11;

  -GtkTreeView-horizontal-separator: 4;

  -GtkWidget-text-handle-width: 20;
  -GtkWidget-text-handle-height: 24;

  -GtkDialog-button-spacing: 4;
  -GtkDialog-action-area-border: 0;

  // We use the outline properties to signal the focus properties
  // to the adwaita engine: using real CSS properties is faster,
  // and we don't use any outlines for now.

  outline-color: transparentize($fg_color, 0.7);
  outline-style: dashed;
  outline-offset: -3px;
  outline-width: 1px;
  -gtk-outline-radius: 2px;
}


/***************
 * Base States *
 ***************/

.background {
  color: $fg_color;
  background-color: $bg_color;

  &:backdrop {
    text-shadow: none;
    -gtk-icon-shadow: none;
    color: $backdrop_fg_color;
    background-color: $backdrop_bg_color;
  }
}

/*
   These wildcard seems unavoidable, need to investigate.
   Wildcards are bad and troublesome, use them with care,
   or better, just don't.
   Everytime a wildcard is used a kitten dies, painfully.
*/

*:insensitive {
  -gtk-icon-effect: dim;
}

.gtkstyle-fallback {
  background-color: $bg_color;
  color: $fg_color;
  &:prelight {
    background-color: lighten($bg_color, 10%);
    color: $fg_color;
  }
  &:active {
    background-color: darken($bg_color, 10%);
    color: $fg_color;
  }
  &:insensitive {
    background-color: $insensitive_bg_color;
    color: $insensitive_fg_color;
  }
  &:selected {
    background-color: $selected_bg_color;
    color: $selected_fg_color;
  }
}

textview text,
.view {
  color: $text_color;
  background-color: $base_color;

  &:backdrop {
    color: $backdrop_text_color;
    background-color: $backdrop_base_color;
  }
  & selection,
  & selection:focus {
    @extend %selected_items;
  }
}

iconview {
  color: $text_color;
  background-color: $base_color;
  &:backdrop {
    color: $backdrop_text_color;
    background-color: $backdrop_base_color;
  }
  &:selected,
  &:selected:focus {
    @extend %selected_items;
  }
}

.rubberband,
rubberband {
  border: 1px solid darken($selected_bg_color, 10%);
  background-color: transparentize(darken($selected_bg_color, 10%), 0.8);
}

flowbox {
  & rubberband { @extend rubberband; }
  & flowboxchild {
    padding: 3px;
    border-radius: 3px;
    &:selected {
      @extend %selected_items;
      outline-offset: -2px;
    }
  }
}

label {
  &.separator {
    color: $fg_color;
    @extend .dim-label;
    &:backdrop { color: $backdrop_fg_color; }
  }
  &:selected,
  & selection,
  & selection:focus,
  & selection:hover {
    @extend %selected_items;
  }
  &:insensitive {
    color: $insensitive_fg_color;
    &:backdrop { color: $backdrop_insensitive_color; }
  }
}

.dim-label {
  opacity: 0.55;
  text-shadow: none;
}

assistant {
  .sidebar {
    background-color: $base_color;
    border-top: 1px solid $borders_color;
    &:dir(ltr) { border-right: 1px solid $borders_color; }
    &:dir(rtl) { border-left: 1px solid $borders_color; }
    &:backdrop {
      background-color: $backdrop_base_color;
      border-color: $backdrop_borders_color;
    }
  }
  &.csd .sidebar { border-top-style: none; }
  .sidebar label {
    padding: 6px 12px;
  }
  .sidebar label.highlight {
    background-color: mix($bg_color, $fg_color, 80%);
  }
}

textview { // This will get overridden by .view, needed by gedit line numbers
  background-color: mix($bg_color, $base_color, 50%);
  &:backdrop { background-color: mix($backdrop_bg_color,
                                     $backdrop_base_color, 50%); }
}

%osd, .osd {
  color: $osd_fg_color;
  border: none;
  background-color: $osd_bg_color;
  background-clip: padding-box;
  outline-color: transparentize($osd_fg_color, 0.7);
  text-shadow: 0 1px black;
  -gtk-icon-shadow: 0 1px black;
  &:backdrop {
    text-shadow: none;
    -gtk-icon-shadow: none;
  }
}

/*********************
 * Spinner Animation *
 *********************/

@keyframes spin {
  to { -gtk-icon-transform: rotate(1turn); }
}

spinner {
  background: none;
  opacity: 0; // non spinning spinner makes no sense
  -gtk-icon-source: -gtk-icontheme('process-working-symbolic');
  &:checked {
    opacity: 1;
    animation: spin 1s linear infinite;
    &:insensitive {
      opacity: 0.5;
    }
  }
}

/****************
 * Text Entries *
 ****************/

entry {
  border: 1px solid;
  padding: 5px 8px 6px;

  & image { // icons inside the entry
    &.left { padding-left: 0; padding-right: 6px; }
    &.right { padding-left: 6px; padding-right: 0; }
  }

  border-radius: 3px;
  transition: all 200ms $ease-out-quad;
  @include entry(normal);

  &.flat, &.flat:focus {
    padding: 2px;
    @include entry(normal, $edge:none);
    border: none;
    border-radius: 0;
  }

  &:focus { @include entry(focus); }
  &:insensitive { @include entry(insensitive); }
  &:backdrop { @include entry(backdrop); }
  &:backdrop:insensitive { @include entry(backdrop-insensitive); }

  & selection,
  & selection:focus {
    @extend %selected_items;
  }

  & progress {
    margin: 1px;
    border-radius: 0;
    border-width: 0 0 2px;
    border-color: $selected_bg_color;
    border-style: solid;
    background-image: none;
    background-color: transparent;
    box-shadow: none;
    &:backdrop { background-color: transparent; }
  }

  .linked:not(.vertical) > & { @extend %linked; }

  .linked:not(.vertical) > &:focus + entry,
  .linked:not(.vertical) > &:focus + button,
  .linked:not(.vertical) > &:focus + combobox > button.combo {
    border-left-color: entry_focus_border(); // colors the border of the widget following a focused entry
  }

  // entry error and warning style
  @each $e_type, $e_color in (error, $error_color),
                             (warning, $warning_color) {
    &.#{$e_type} {
      color: $e_color;
      border-color: entry_focus_border($e_color);
      &:focus { @include entry(focus, $e_color); }
      &:selected, &:selected:focus { background-color: $e_color; }
    }
  }

  & image { // entry icons colors
    color: mix($fg_color, $base_color, 80%);
    &:hover { color: $fg_color; }
    &:active { color: $selected_bg_color; }
    &:backdrop { color: mix($backdrop_fg_color, $backdrop_base_color, 80%); }
  }

  .osd & {
    @include entry(osd);
    &:focus { @include entry(osd-focus); }
    &:backdrop { @include entry(osd-backdrop); }
    &:insensitive { @include entry(osd-insensitive); }
  }
}

// Vertically linked entries
// FIXME: take care of "colored" entries
.linked.vertical {
  > entry { @extend %linked_vertical; }

  // remove the edge hilight and the focus shadow (unfortunatelly)
  > entry:not(:last-child) { box-shadow: none; }
  // add back the focus shadow
  > entry:focus:not(:last-child) { box-shadow: entry_focus_shadow(); }

  // brighter border between linked entries
  > entry:not(:insensitive) + entry:not(:insensitive) {
    border-top-color: mix($borders_color, $base_color, 30%);
    background-image: linear-gradient(to bottom, $base_color);
    &:backdrop {
      border-top-color: mix($backdrop_borders_color, $backdrop_base_color, 30%);
      background-image: linear-gradient(to bottom, $backdrop_base_color);
    }
  }

  // brighter border between linked insensitive entries
  > entry:insensitive + entry:insensitive {
    border-top-color: mix($borders_color, $base_color, 30%);
  }

  // color back the top border of a linked focused entry following another entry and add back the focus shadow.
  > entry + entry:focus:not(:last-child) {
    border-top-color: entry_focus_border();
    box-shadow: entry_focus_shadow();
  }
  // just recolor the top border on the last focused entry, since we don't reset the shadow here letting that be
  // inherited by the entry styling.
  > entry + entry:focus:last-child {
    border-top-color: entry_focus_border();
  }

  // this takes care of coloring the top border of the focused entry subsequent widget.
  // :not(:only-child) is a specificity bump hack.
  > entry:focus:not(:only-child) + entry,
  > entry:focus:not(:only-child) + button,
  > entry:focus:not(:only-child) + combobox > button.combo {
    border-top-color: entry_focus_border();
  }
}


/***********
 * Buttons *
 ***********/

// stuff for .needs-attention
$_dot_color: if($variant=='light', $selected_bg_color,
                                   lighten($selected_bg_color,15%));
@keyframes needs_attention {
  from {
    background-image: -gtk-gradient(radial,
                                    center center, 0,
                                    center center, 0.01,
                                    to($_dot_color),
                                    to(transparent));
  }
  to {
    background-image: -gtk-gradient(radial,
                                    center center, 0,
                                    center center, 0.5,
                                    to($selected_bg_color),
                                    to(transparent));
  }
}

button {

  $_button_transition: all 200ms $ease-out-quad;

  border: 1px solid;
  border-radius: 3px;
  padding: 5px 8px 6px;
  transition: $_button_transition;
  @include button(normal);
  &.flat {
    @include button(undecorated);
    // to avoid adiacent buttons borders clashing when transitioning, the transition on the normal state is set
    // to none, while it's added back in the hover state, so the button decoration will fade in on hover, but
    // it won't fade out when the pointer leave the button allocation area. To make the transition more evident
    // in this case the duration is increased.
    transition: none;
    &:hover {
      transition: $_button_transition;
      transition-duration: 500ms;
      &:active { transition: $_button_transition; }
    }
  }
  &:hover {
    @include button(hover);
    -gtk-icon-effect: highlight;
  }
  &:active, &:checked {
    @include button(active);
    transition-duration: 50ms;
  }
  &:backdrop, &.flat:backdrop {
    @include button(backdrop);
    -gtk-icon-effect: none;
    &:active, &:checked {
      @include button(backdrop-active);
    }
    &:insensitive {
      @include button(backdrop-insensitive);
    }
    &:insensitive:active, &:insensitive:checked {
      @include button(backdrop-insensitive-active);
    }
  }
  &.flat:backdrop, &.flat:insensitive, &.flat:backdrop:insensitive {
    @include button(undecorated);
  }
  &:insensitive {
    @include button(insensitive);
    &:active, &:checked {
      @include button(insensitive-active);
    }
  }
  // big standalone buttons like in Documents pager
  &.osd {
    &.image-button { padding: 13px; }
    color: $osd_fg_color;
    border-radius: 5px;
    outline-color: transparentize($osd_fg_color, 0.7);  //FIXME: define a color var?
    @include button(osd);
    border: none;
    box-shadow: none;
    &:hover {
      @include button(osd-hover);
      border: none;
      box-shadow: none;
    }
    &:active, &:checked {
      @include button(osd-active);
      border: none;
      box-shadow: none;
    }
    &:insensitive, &:backdrop:insensitive {
      @include button(osd-insensitive);
      border: none;
    }
    &:backdrop {
      @include button(osd-backdrop);
      border: none;
    }
  }
  //overlay / OSD style
  @at-root %osd_button,
  .osd & {
    @include button(osd);
    &:hover {
      @include button(osd-hover);
    }
    &:active, &:checked, &:backdrop:active, &:backdrop:checked {
      @include button(osd-active);
    }
    &:insensitive, &:backdrop:insensitive {
      @include button(osd-insensitive);
    }
    &:backdrop {
      @include button(osd-backdrop);
    }
    &.flat {
      @include button(undecorated);
      box-shadow: none; //FIXME respect no edge on the button mixin
      text-shadow: 0 1px black;
      -gtk-icon-shadow: 0 1px black;
      &:hover {
        @include button(osd-hover);
      }
      &:insensitive {
        @include button(osd-insensitive);
        background-image: none;
        border-color: transparent;
        box-shadow: none;
      }
      &:backdrop { @include button(undecorated); }
      &:active, &:checked { @include button(osd-active); }
    }
  }

  // Suggested and Destructive Action buttons
  @each $b_type, $b_color in (suggested-action, $selected_bg_color),
                             (destructive-action, $destructive_color) {
    &.#{$b_type} {
      @include button(normal, $b_color, white);
      &.flat {
        @include button(undecorated);
        color: $b_color; //FIXME: does it work on the dark variant?
      }
      &:hover { @include button(hover, $b_color, white); }
      &:active, &:checked { @include button(active, $b_color, white); }
      &:backdrop, &.flat:backdrop {
        @include button(backdrop, $b_color, white);
        &:active, &:checked {
          @include button(backdrop-active, $b_color, white);
        }
        &:insensitive {
          @include button(backdrop-insensitive);
          &:active, &:checked {
            @include button(backdrop-insensitive-active, $b_color, white);
          }
        }
      }
      &.flat:backdrop, &.flat:insensitive, &.flat:backdrop:insensitive {
        @include button(undecorated);
        color: transparentize($b_color, 0.2);
      }
      &:insensitive {
        @include button(insensitive);
        &:active, &:checked {
          @include button(insensitive-active, $b_color, white);
        }
      }
      .osd & {
        @include button(osd, $b_color);
        &:hover {
          @include button(osd-hover, $b_color);
        }
        &:active, &:checked, &:backdrop:active, &:backdrop:checked {
          @include button(osd-active, $b_color);
        }
        &:insensitive, &:backdrop:insensitive {
          @include button(osd-insensitive, $b_color);
        }
        &:backdrop {
          @include button(osd-backdrop, $b_color);
        }
      }
    }
  }

  &.image-button { padding: 8px; }

  &.text-button {
    padding-left: 16px;
    padding-right: 16px;
  }

  &.text-button.image-button {
    // those buttons needs uneven horizontal padding, we want the icon side
    // to have the image-button padding, while the text side the text-button
    // one, so we're adding the missing padding to the label depending on
    // its position inside the button
    padding: 5px 8px 6px; // same as .button
    & label:first-child { padding-left: 8px; }
    & label:last-child { padding-right: 8px; }
  }

  .stack-switcher > & {
    // to position the needs attention dot, padding is added to the button
    // child, a label needs just lateral padding while an icon needs vertical
    // padding added too.

    outline-offset: -3px; // needs to be set or it gets overriden by GtkRadioButton outline-offset

    > label {
      padding-left: 6px;  // label padding
      padding-right: 6px; //
    }
    > image {
      padding-left: 6px;   // image padding
      padding-right: 6px;  //
      padding-top: 3px;    //
      padding-bottom: 3px; //
    }
    &.text-button {
      padding: 5px 10px 6px; // needed or it will get overridden
    }
    &.image-button {
      // we want image buttons to have a 1:1 aspect ratio, so compensation
      // of the padding added to the GtkImage is needed
      padding: 5px 2px;
    }
    &.needs-attention > label,
    &.needs-attention > image { @extend %needs_attention; }
    &.needs-attention:active > label,
    &.needs-attention:active > image,
    &.needs-attention:checked > label,
    &.needs-attention:checked > image {
      animation: none;
      background-image: none;
    }
  }

  //inline-toolbar buttons
  .inline-toolbar &, .inline-toolbar &:backdrop {
    border-radius: 2px;
    border-width: 1px;
    @extend %linked;
  }

  .primary-toolbar & { -gtk-icon-shadow: none; } // tango icons don't need shadows

  .linked > &,
  .linked > &:hover,
  .linked > &:active,
  .linked > &:checked,
  .linked > &:backdrop { @extend %linked; }

  .linked.vertical > &,
  .linked.vertical > &:hover,
  .linked.vertical > &:active,
  .linked.vertical > &:checked,
  .linked.vertical > &:backdrop { @extend %linked_vertical; }
}

%needs_attention {
  animation: needs_attention 150ms ease-in;
  $_dot_shadow: _text_shadow_color();
  $_dot_shadow_r: if($variant=='light',0.5,0.45);
  background-image: -gtk-gradient(radial,
                                  center center, 0,
                                  center center, 0.5,
                                  to($_dot_color),
                                  to(transparent)),
                    -gtk-gradient(radial,
                                  center center, 0,
                                  center center, $_dot_shadow_r,
                                  to($_dot_shadow),
                                  to(transparent));
  background-size: 6px 6px, 6px 6px;
  background-repeat: no-repeat;
  @if $variant == 'light' { background-position: right 3px, right 4px; }
  @else { background-position: right 3px, right 2px; }
  &:backdrop { background-size: 6px 6px, 0 0;}
  &:dir(rtl) {
    @if $variant == 'light' { background-position: left 3px, left 4px; }
    @else { background-position: left 3px, left 2px; }
  }
}


// all the following is for the +|- buttons on inline toolbars, that way
// should really be deprecated...
.inline-toolbar toolbutton > button { // redefining the button look is
                                          // needed since those are flat...
  @include button(normal);
  &:hover { @include button(hover); }
  &:active,
  &:checked{ @include button(active); }
  &:insensitive { @include button(insensitive); }
  &:insensitive:active,
  &:insensitive:checked { @include button(insensitive-active); }
  &:backdrop { @include button(backdrop); };
  &:backdrop:active,
  &:backdrop:checked { @include button(backdrop-active); }
  &:backdrop:insensitive { @include button(backdrop-insensitive); }
  &:backdrop:insensitive:active,
  &:backdrop:insensitive:checked {
    @include button(backdrop-insensitive-active); }
}

// More inline toolbar buttons
toolbar.inline-toolbar toolbutton,
toolbar.inline-toolbar toolbutton:backdrop {
  & > button.flat { @extend %linked_middle; }
  &:first-child > button.flat { @extend %linked:first-child; }
  &:last-child > button.flat { @extend %linked:last-child; }
  &:only-child > button.flat { @extend %linked:only-child; }
}

toolbar separator {
  background: none;
}

%linked_middle {
  border-radius: 0;
  border-right-style: none;
}

%linked {
  @extend %linked_middle;
  &:first-child {
    border-top-left-radius: 3px;
    border-bottom-left-radius: 3px;
  }
  &:last-child {
    border-top-right-radius: 3px;
    border-bottom-right-radius: 3px;
    border-right-style: solid;
  }
  &:only-child {
    border-radius: 3px;
    border-style: solid;
  }
}

%linked_vertical_middle {
  border-style: solid solid none solid;
  border-radius: 0;
}

%linked_vertical{
  @extend %linked_vertical_middle;
  &:first-child {
    border-top-left-radius: 3px;
    border-top-right-radius: 3px;
  }
  &:last-child {
    border-bottom-left-radius: 3px;
    border-bottom-right-radius: 3px;
    border-style: solid;
  }
  &:only-child {
    border-radius: 3px;
    border-style: solid;
  }
}

%undecorated_button {
  border-color: transparent;
  background-color: transparent;
  background-image: none;
  box-shadow: inset 0 1px transparentize(white,1),
              0 1px transparentize(white, 1);
  text-shadow: none;
  -gtk-icon-shadow: none;
}

/* menu buttons */
modelbutton.flat,
.menuitem.button.flat {
  @extend %undecorated_button;
  outline-offset: -1px;
  &:hover { background-color: mix($fg_color, $bg_color, 10%); }
  &:selected { @extend %selected_items; }
  &:backdrop, &:backdrop:hover {
    @extend %undecorated_button;
  }
}

modelbutton.flat arrow {
  background: none;
  &:hover { background: none; }
  &.left { -gtk-icon-source: -gtk-icontheme("pan-start-symbolic"); }
  &.right { -gtk-icon-source: -gtk-icontheme("pan-end-symbolic"); }
}

button.color {
  padding: 5px; // Uniform padding on the GtkColorButton

  > colorswatch:first-child:last-child { // :first-child:last-child for a specificity bump, it gets overridden by the colorchooser style
    > overlay, & { border-radius: 0; }
    box-shadow: inset 0 1px 1px transparentize(black, 0.9),
                _widget_edge();
    &:insensitive,
    &:backdrop { box-shadow: none; }
  }
}

/*********
 * Links *
 *********/

*:link {
  color: $link_color;
  &:visited {
    color: $link_visited_color;
    *:selected & { color: mix($selected_fg_color, $selected_bg_color, 60%); }
  }
  &:hover {
    color: lighten($link_color,10%);
    *:selected & { color: mix($selected_fg_color, $selected_bg_color, 90%); }
  }
  &:active {
    color: $link_color;
    *:selected & { color: mix($selected_fg_color, $selected_bg_color, 80%); }
  }
  &:backdrop, &:backdrop:hover, &:backdrop:hover:selected {
    color: $selected_bg_color;
  }
  &:selected, *:selected & {
    color: mix($selected_fg_color, $selected_bg_color, 80%);
  }
}

button:link, button:visited {
  @extend %undecorated_button;
  @extend *:link;
  text-shadow: none;
  &:hover, &:active, &:checked {
    @extend %undecorated_button;
    text-shadow: none;
  }
  &:backdrop {
    @extend %undecorated_button; //This shouldn't be needed but avoids
                                 //a weird transition which for some reason
                                 //makes borders blink on hover
  }
  & > label {
    text-decoration-line: underline;
  }
}

/*****************
 * GtkSpinButton *
 *****************/

spinbutton {
  @extend entry;
  &:not(.vertical) {
    button {
      background-image: none;
      border-style: none none none solid;
      border-color: transparentize($borders_color, 0.7);
      color: mix($fg_color, $base_color, 90%);
      border-radius: 0;
      box-shadow: none;
      &:dir(rtl) { border-style: none solid none none; }
      &:hover {
        color: $fg_color;
        background-color: transparentize($fg_color, 0.95);
      }
      &:insensitive {
        color: transparentize($insensitive_fg_color, 0.7);
      }
      &:active {
        box-shadow: inset 0 2px 3px -1px transparentize(black, 0.8);
        background-color: transparentize(black, 0.9);
      }
      &:backdrop {
        color: mix($backdrop_fg_color, $backdrop_base_color, 90%);
        border-color: transparentize($backdrop_borders_color, 0.7);
        background-color: transparent;
      }
      &:backdrop:insensitive {
        background-image: none;
        color: transparentize($backdrop_insensitive_color,0.7);
        border-style: none none none solid; // It is needed or it gets overridden
        &:dir(rtl) { border-style: none solid none none; }
      }
    }
  }

  // OSD horizontal
  .osd &:not(.vertical) {
     button {
      @include button(undecorated);
      color: $osd_fg_color;
      border-style: none none none solid;
      border-color: transparentize($osd_borders_color, 0.3);
      border-radius: 0;
      box-shadow: none;
      -gtk-icon-shadow: 0 1px black;
      &:dir(rtl) { border-style: none solid none none; }
      &:hover {
        @include button(undecorated);
        color: $osd_fg_color;
        border-color: transparentize(opacify($osd_borders_color, 1), 0.5);
        background-color: transparentize($osd_fg_color, 0.9);
        -gtk-icon-shadow: 0 1px black;
        box-shadow: none;
      }
      &:backdrop {
        @include button(undecorated);
        color: $osd_fg_color;
        border-color: transparentize(opacify($osd_borders_color, 1), 0.5);
        -gtk-icon-shadow: none;
        box-shadow: none;
      }
      &:insensitive {
        @include button(undecorated);
        color: $osd_insensitive_fg_color;
        border-color: transparentize(opacify($osd_borders_color, 1), 0.5);
        -gtk-icon-shadow: none;
        box-shadow: none;
      }
      &:last-child { border-radius: 0 3px 3px 0; }
      &:dir(rtl):first-child { border-radius: 3px 0 0 3px; }
    }
  }

  // Vertical
  &.vertical {
    border-radius: 0;
    padding-left: 4px;
    padding-right: 4px;
    button {
      padding-top: 8px;    //  Same vertical padding as image-buttons
      padding-bottom: 8px; //
      &:first-child {
        @extend %top_button;
        @include button(normal, $edge:none);
        &:active {
          @extend %top_button;
          @include button(active, $edge:none);
        }
        &:hover {
          @extend %top_button;
          @include button(hover, $edge:none);
        }
        &:insensitive {
          @extend %top_button;
          @include button(insensitive, $edge:none);
        }
        &:backdrop {
          @extend %top_button;
          @include button(backdrop, $edge:none);
          &:insensitive { @include button(backdrop-insensitive, $edge:none); }
        }
      }
      &:last-child { @extend %bottom_button; }
    }
    %top_button {
      border-radius: 3px 3px 0 0;
      border-style: solid solid none solid;
    }
    %bottom_button {
      border-radius: 0 0 3px 3px;
      border-style: none solid solid solid;
    }
  }

  // OSD vertical
  .osd &.vertical button:first-child {
    @include button(osd);
    &:hover { @include button(osd-hover);}
    &:active { @include button(osd-active); }
    &:insensitive { @include button(osd-insensitive); }
    &:backdrop { @include button(osd-backdrop); }
  }

  // Misc
  treeview & {
    & entry, & entry:focus {
      padding: 1px;
      border-width: 1px 0;
      border-color: $selected_bg_color;
      border-radius: 0;
      box-shadow: none;
    }
  }
}

/**************
 * ComboBoxes *
 **************/
combobox {
  > button.combo { padding-top: 3px; padding-bottom: 4px; } // Otherwise combos
                                                                           // are bigger then
                                                                           // buttons
  @include _button_text_shadow;

  &:insensitive {
    color: $insensitive_fg_color;
    text-shadow: none;
    -gtk-icon-shadow: none;
  }
  &:backdrop {
    color: $backdrop_fg_color;
    text-shadow: none;
    -gtk-icon-shadow: none;
  }
  &:backdrop:insensitive {
    color: $backdrop_insensitive_color;
  }
  & arrow {
    -gtk-icon-source: -gtk-icontheme('pan-down-symbolic');
    min-height: 16px;
    min-width: 16px;
  }
  & menuitem { text-shadow: none; }
  & > entry.combo {
    &:dir(ltr) {
      border-top-right-radius: 0;
      border-bottom-right-radius: 0;
    }
    &:dir(rtl) {
      border-top-left-radius: 0;
      border-bottom-left-radius: 0;
    }
  }
  & > button.combo:not(:only-child) {
    &:dir(ltr) {
      border-top-left-radius: 0;
      border-bottom-left-radius: 0;
      border-left-style: none;
    }
    &:dir(rtl) {
      border-top-right-radius: 0;
      border-bottom-right-radius: 0;
      border-right-style: none;
    }
  }
}

.linked > combobox > button.combo {
  // the combo is a composite widget so the way we do button linkind doesn't
  // work, special case needed. See
  // https://bugzilla.gnome.org/show_bug.cgi?id=733979
  &:dir(ltr),
  &:dir(rtl) { @extend %linked_middle; } // specificity bump
}
.linked > combobox:first-child > button.combo {
  @extend %linked:first-child;
}
.linked > combobox:last-child > button.combo {
  @extend %linked:last-child;
}
.linked > combobox:only-child > button.combo {
  @extend %linked:only-child;
}
.linked.vertical > combobox > button.combo {
  @extend %linked_vertical_middle;
}
.linked.vertical > combobox:first-child > button.combo {
  @extend %linked_vertical:first-child;
}
.linked.vertical > combobox:last-child > button.combo {
  @extend %linked_vertical:last-child;
}
.linked.vertical > combobox:only-child > button.combo {
  @extend %linked_vertical:only-child;
}

/************
 * Toolbars *
 ************/
toolbar {
  -GtkWidget-window-dragging: true;
  padding: 4px;
  background-color: $bg_color;
  // on OSD
  .osd & { background-color: transparent; }

  // stand-alone OSD toolbars
  &.osd {
    padding: 13px;
    border: none;
    border-radius: 5px;
    background-color: $osd_bg_color;
  }

  &.osd.left,
  &.osd.right,
  &.osd.top,
  &.osd.bottom { border-radius: 0; } // positional classes for `attached` osd toolbars
}

//searchbar, location-bar & inline-toolbar
.inline-toolbar {
  @extend toolbar;
  @extend %inset-bar;
  border-width: 0 1px 1px;
  padding: 3px;
  border-radius: 0  0 5px 5px;
}
searchbar,
.location-bar {
  @extend toolbar;
  @extend %inset-bar;
  border-width: 0 0 1px;
  padding: 3px;
}

%inset-bar {
  border-style: solid;
  border-color: $borders_color;
  $_bg: mix($bg_color, $borders_color, 70%);
  background-color: $_bg;
  box-shadow: inset 0 2px 3px -1px mix($borders_color, $_bg, 60%),
              _widget_edge();
  //FIXME edge would be nice, but doesn't work
  &:backdrop {
    border-color: $backdrop_borders_color;
    background-color: $backdrop_dark_fill;
    box-shadow: none;
  }
}

/***************
 * Header bars *
 ***************/

%titlebar,
headerbar {
  padding: 6px;
  border-width: 0 0 1px;
  border-style: solid;
  border-color: $borders_color;
  border-radius: 0;

  background-color: transparent;

  @include headerbar_fill;

  &:backdrop {
    border-color: $backdrop_borders_color;
    background-color: $bg_color;
    background-image: none;
    box-shadow: inset 0 1px $top_hilight;
  }

  .title {
    font-weight: bold;
    padding-left: 12px;
    padding-right: 12px;
  }

  .subtitle {
    font-size: smaller;
    padding-left: 12px;
    padding-right: 12px;
    @extend .dim-label;
  }

  .header-bar-separator,
  & > GtkBox > separator.vertical {
    -GtkWidget-wide-separators: true;
    -GtkWidget-separator-width: 1px;
    border-width: 0 1px;
    border-image: linear-gradient(to bottom,
                                  transparentize($borders_color,1),
                                  $borders_color 30%,
                                  $borders_color 70%,
                                  transparentize($borders_color,1) 100%)
                  0 1 / 0 1px stretch; //FIXME use a proper color

    &:backdrop {
      border-image: linear-gradient(to bottom, transparentize($backdrop_borders_color, 0.5))
                    0 1 / 1px 1px;  //FIXME use a proper color
    }
  }

  &.selection-mode {
    $_hc: mix($top_hilight,$selected_bg_color, 50%); // hilight color

    color: $selected_fg_color;
    text-shadow: 0 -1px transparentize(black, 0.5);
    border-color: $selected_borders_color;
    background-image: linear-gradient(to bottom,
                                      lighten($selected_bg_color,5%),
                                      $selected_bg_color);
    box-shadow: inset 0 -1px mix($selected_borders_color, $selected_bg_color, 35%), //bottom shade
                inset 0 1px $_hc;

    &:backdrop {
      background-image: linear-gradient(to bottom, $selected_bg_color);
      box-shadow: inset 0 1px mix($top_hilight, $selected_bg_color, 60%);
    }

    .subtitle:link { @extend *:link:selected;  }

    button {
      @include button(normal, $selected_bg_color, $selected_fg_color, $_hc);

      &.flat { @include button(undecorated); }

      &:hover { @include button(hover, $selected_bg_color, $selected_fg_color, $_hc); }

      &:active, &:checked { @include button(active, $selected_bg_color, $selected_fg_color, $_hc); }

      &:backdrop,
      &.flat:backdrop {
        @include button(backdrop, $selected_bg_color, $selected_fg_color, $_hc);
        -gtk-icon-effect: none;
        border-color: $selected_borders_color;

        &:active,
        &:checked {
          @include button(backdrop-active, $selected_bg_color, $selected_fg_color, $_hc);
          border-color: $selected_borders_color;
        }

        &:insensitive {
          @include button(backdrop-insensitive, $selected_bg_color, $selected_fg_color, $_hc);
          border-color: $selected_borders_color;
        }

        &:insensitive:active,
        &:insensitive:checked {
          @include button(backdrop-insensitive-active, $selected_bg_color,
                          $selected_fg_color, $_hc);
          border-color: $selected_borders_color;
        }
      }

      &.flat:backdrop,
      &.flat:insensitive,
      &.flat:insensitive:backdrop {
        @include button(undecorated);
      }

      &:insensitive {
        @include button(insensitive, $selected_bg_color, $selected_fg_color, $_hc);

        &:active, &:checked { @include button(insensitive-active, $selected_bg_color, $selected_fg_color, $_hc); }
      }

      &.suggested-action {
        @include button(normal, $edge:$_hc);
        border-color: $selected_borders_color;

        &:hover {
          @include button(hover, $edge:$_hc);
          border-color: $selected_borders_color;
        }

        &:active {
          @include button(active, $edge:$_hc);
          border-color: $selected_borders_color;
        }

        &:insensitive {
          @include button(insensitive, $edge:$_hc);
          border-color: $selected_borders_color;
        }

        &:backdrop {
          @include button(backdrop, $edge:$_hc);
          border-color: $selected_borders_color;
        }

        &:backdrop:insensitive {
          @include button(backdrop-insensitive, $edge:$_hc);
          border-color: $selected_borders_color;
        }
      }
    }

    .selection-menu {
      border-color: transparentize($selected_bg_color, 1);
      background-image: linear-gradient(to bottom, transparentize($selected_bg_color, 1));
      box-shadow: none;
      padding-left: 10px;
      padding-right: 10px;

      GtkArrow { -GtkArrow-arrow-scaling: 1; }

      .arrow {
        -gtk-icon-source: -gtk-icontheme('pan-down-symbolic');
        color: transparentize($selected_fg_color,0.5);
        -gtk-icon-shadow: none;
      }

      &:backdrop { @extend .selection-menu };
    }
  }

  .tiled &, .maximized & {
    border-radius: 0; // squared corners when the window is max'd or tiled
  }

  &.default-decoration {
    padding: 4px;
    button { padding: 5px; }
  }
}

.titlebar {
  &, &:backdrop {
    border-top-left-radius: 7px;
    border-top-right-radius: 7px;
  }
}

headerbar {
  separator:first-child + &, // tackles the paned container case
  &:first-child { &, &:backdrop { border-top-left-radius: 7px; }}
  &:last-child { &, &:backdrop { border-top-right-radius: 7px; }}
}

.titlebar:not(headerbar) {
  window.csd > & {
    // in csd we assume every titlebar is a headerbar so reset anything, this is needed for split toolbars cases
    padding: 0;
    background-color: transparent;
    background-image: none;
    border-style: none;
    border-color: transparent;
    box-shadow: none;
  }
  @extend %titlebar;
}

/************
 * Pathbars *
 ************/

.path-bar button {
  padding: 5px 6px 6px;
  &:first-child { padding-left: 8px; }
  &:last-child { padding-right: 8px; }
  &:only-child {
    padding-left: 12px;
    padding-right: 12px;
  }

  // the following is for spacing the icon and the label inside the home button
  & label:last-child { padding-left: 2px; }
  & label:first-child { padding-right: 2px; }
  & label:only-child { padding-right: 0; padding-left: 0; }
  image { padding-top: 1px; }
}

/**************
 * Tree Views *
 **************/
treeview.view {
  -GtkTreeView-grid-line-width: 1;
  -GtkTreeView-grid-line-pattern: '';
  -GtkTreeView-tree-line-width: 1;
  -GtkTreeView-tree-line-pattern: '';
  -GtkTreeView-expander-size: 16;

  border-left-color: mix($fg_color, $base_color, 50%); // this is actually the tree lines color,
  border-top-color: $bg_color;                         // while this is the grid lines color, better then nothing

  & rubberband { @extend rubberband; } // to avoid borders being overridden by the previously set props

  &:selected {
    border-radius: 0;
    @extend %selected_items;
  }

  &:selected, &:backdrop:selected {
    border-left-color: mix($selected_fg_color, $selected_bg_color, 50%);
    border-top-color: transparentize($fg_color, 0.9); // doesn't work unfortunatelly
  }

  &:insensitive {
    color: $insensitive_fg_color;
    &:selected {
      color: mix($selected_fg_color, $selected_bg_color, 40%);
      &:backdrop { color: mix($backdrop_selected_fg_color, $selected_bg_color, 30%); }
    }
    &:backdrop { color: $backdrop_insensitive_color; }
  }

  &.separator:backdrop {
    color: transparentize(black, 0.9);
  }

  &:backdrop {
    border-left-color: mix($backdrop_fg_color, $backdrop_bg_color, 50%);
    border-top: $backdrop_bg_color;
  }

  &.dnd {
    border-style: solid none;
    border-width: 1px;
    border-color: mix($fg_color, $selected_bg_color, 50%);
  }

  &.expander {
    -gtk-icon-source: -gtk-icontheme('pan-end-symbolic');
    &:dir(rtl) { -gtk-icon-source: -gtk-icontheme('pan-end-symbolic-rtl'); }
    color: mix($fg_color, $base_color, 70%);
    &:hover { color: $fg_color; }
    &:selected {
      color: mix($selected_fg_color, $selected_bg_color, 70%);
      &:hover { color: $selected_fg_color; }
      &:backdrop { color: mix($backdrop_selected_fg_color, $selected_bg_color, 70%); }
    }

    &:checked { -gtk-icon-source: -gtk-icontheme('pan-down-symbolic'); }

    &:backdrop { color: mix($backdrop_fg_color, $backdrop_base_color, 70%); }
  }

  &.progressbar { // progress bar in treeviews
    @if $variant == light { color: $base_color; }

    border: 1px solid $selected_borders_color;
    border-radius: 4px;
    background-image: linear-gradient(to bottom,
                                      $selected_bg_color,
                                      darken($selected_bg_color,10%));
    box-shadow: inset 0 1px if($variant=='light', transparentize(white,0.7),
                                                  transparentize(white,0.85)),
                      0 1px if($variant=='light', transparentize(black, 0.8),
                                                  transparentize(black,0.9));

    &:selected {
      @if $variant == 'light' {
         color: $selected_bg_color;
         box-shadow: none;
      }

      @else { box-shadow: inset 0 1px transparentize(white, 0.95); }

      background-image: linear-gradient(to bottom,
                                        $base_color,
                                        darken($base_color,10%));

      &:backdrop {
        @if $variant == 'light' {
          color: $selected_bg_color;
          border-color: $selected_borders_color; // otherwise it gets inherited by .view(?!?)
        }
        @else { border-color: $backdrop_base_color; }
        background-color: $backdrop_base_color;
      }
    }

    &:backdrop {
      @if $variant == 'light' { color: $backdrop_base_color; }
      @else { border-color: $backdrop_base_color; }
      background-image: none;
      box-shadow: none;
    }
  }

  &.trough { // progress bar trough in treeviews
    background-color: transparentize($fg_color,0.9);
    border-radius: 4px;

    &:selected {
      background-color: if($variant == 'light',
                           transparentize($selected_fg_color, 0.7),
                           darken($selected_bg_color, 10%));
      @if $variant == 'light' {
        border-width: 1px 0;
        border-style: solid;
        border-color: $selected_bg_color;
      }
    }
  }

  header {
    button {
      @extend %column_header_button;
      $_column_header_color: mix($fg_color, $base_color, 50%);
      color: $_column_header_color;
      background-color: $base_color;
      font-weight: bold;
      text-shadow: none;
      box-shadow: none;
      &:hover {
        @extend %column_header_button;
        color: mix($_column_header_color, $fg_color, 50%);
        box-shadow: none;
        transition: none; //I shouldn't need this
      }
      &:active {
        @extend %column_header_button;
        color: $fg_color;
        transition: none; //I shouldn't need this
      }
      &.dnd {
        @extend header.button.dnd;
      }
    }
    & button:last-child,
    & button:last-child:backdrop {
      border-right-style: none;
    }
  }

  header.button.dnd { // for treeview-like derive widgets
    transition: none;
    color: $selected_bg_color;
    box-shadow: inset 1px 1px 0 1px $selected_bg_color,
                inset -1px 0 0 1px $selected_bg_color,
                inset 1px 1px $base_color, inset -1px 0 $base_color;;
    &:active { @extend header.button.dnd; }
    &:selected { @extend header.button.dnd; }
    &:hover { @extend header.button.dnd; }
  }
}

%column_header_button {
  padding: 3px 6px;
  border-style: none solid solid none;
  border-radius: 0;
  background-image: none;
  border-color: $bg_color;
  text-shadow: none;
  &:insensitive {
    border-color: $bg_color;
    background-image: none;
  }
  &:backdrop {
    border-color: $backdrop_bg_color;
    border-style: none solid solid none;
    color: mix($backdrop_fg_color, $backdrop_bg_color, 50%);
    background-image: none;
    background-color: $backdrop_base_color;
    &:insensitive {
      border-color: $backdrop_bg_color;
      background-image: none;
    }
  }
}


/*********
 * Menus *
 *********/
menubar,
.menubar {
  -GtkWidget-window-dragging: true;
  padding: 0px;
  box-shadow: inset 0 -1px transparentize(black, 0.9);
  &:backdrop { background-color: $backdrop_bg_color; }
  & > menuitem {
    padding: 4px 8px;
    &:hover { //Seems like it :hover even with keyboard focus
      box-shadow: inset 0 -3px $selected_bg_color;
      color: $link_color;
    }
    &:insensitive {
      color: $insensitive_fg_color;
      box-shadow: none;
    }
  }
}

menu,
.menu {
  margin: 4px;
  padding: 0px;
  background-color: $menu_color;
  border: 1px solid $borders_color; // adds borders in a non composited env
  .csd & { border: none; }  // axes borders in a composited env
  &:backdrop { background-color: $backdrop_menu_color; }
  & menuitem {
    text-shadow: none;
    padding: 4px;
    min-width: 40px;
    &:hover {
      color: $selected_fg_color;
      background-color: $selected_bg_color;
    }
    &:insensitive {
      color: $insensitive_fg_color;
      &:backdrop { color: $backdrop_insensitive_color; }
    }
    &:backdrop, &:backdrop:hover {
      color: $backdrop_fg_color;
      background-color: transparent;
    }
    //submenu indicators
    & arrow {
      min-height: 16px;
      min-width: 16px;
    }
    & arrow:dir(ltr) {
      -gtk-icon-source: -gtk-icontheme('pan-end-symbolic');
      margin-left: 10px;
    }
    & arrow:dir(rtl) {
      -gtk-icon-source:-gtk-icontheme('pan-end-symbolic-rtl');
      margin-right: 10px;
    }
  }
  & arrow { // overlow buttons
    @extend %undecorated_button;
    border-style: none;
    border-radius: 0;
    min-height: 16px;
    min-width: 16px;
    &.top {
      -gtk-icon-source: -gtk-icontheme('pan-up-symbolic');
      border-bottom: 1px solid mix($fg_color, $base_color, 10%);
    }
    &.bottom {
      -gtk-icon-source: -gtk-icontheme('pan-down-symbolic');
      border-top: 1px solid mix($fg_color, $base_color, 10%);
    }
    &:hover { background-color: mix($fg_color, $base_color, 10%); }
    &:insensitive {
      color: transparent;
      background-color: transparent;
      border-color: transparent ;
    }
  }
}

menuitem {
  & accelerator { color: gtkalpha(currentColor,0.55); }
  & check,
  & radio {
    min-height: 16px;
    min-width: 16px;
    &:dir(ltr) { margin-right: 7px; }
    &:dir(rtl) { margin-left: 7px; }
  }
}

/***************
 * Popovers   *
 ***************/

popover.background {
  padding: 2px;
  border-radius: 5px;
  .csd &, & { border: 1px solid $borders_color; }
  box-shadow: 0 1px 2px transparentize(black, 0.7);

  &:backdrop {
    box-shadow: none;
  }

  > list,
  > .view,
  > toolbar {
    border-style: none;
    background-color: transparent;
  }

  button.flat,
  button.flat:hover {
    text-shadow: none;
    transition: none;
  }

  button.model.image-button {
    padding: 0px;
  }

  .csd &, & {
    &.touch-selection,
    &.magnifier {
      @extend %osd;
      border: 1px solid transparentize(white, 0.9);
      button { @extend %osd_button };
    }

    &.osd { @extend %osd; }
  }
}

/*************
 * Notebooks *
 *************/

notebook {
  -GtkNotebook-initial-gap: 10;
  -GtkNotebook-arrow-spacing: 5;
  -GtkNotebook-tab-curvature: 0;
  -GtkNotebook-tab-overlap: -8;
  -GtkNotebook-has-tab-gap: false;

  // Through me you go to the grief wracked city;
  // Through me you go to everlasting pain;
  // Through me you go a pass among lost souls.
  // ...
  // Abandon all hope — Ye Who Enter Here
  padding: 0;
  background-color: $base_color;
  transition: all 200ms $ease-out-quad;
  &:backdrop {
    background-color: $backdrop_base_color;
  }
  &.frame {
    border: 1px solid $borders_color;
    &:backdrop { border-color: $backdrop_borders_color; }
  }

  & header {
    //vertical tab sizing
    $vt_vpadding: 8px;
    $vt_hpadding: 20px;
    // horizontal tab sizing
    $ht_vpadding: 5px;
    $ht_hpadding: 20px;
    $tab_indicator_size: 3px;
    $_header_shade: inset 0 2px 3px -1px transparentize(black, 0.85);

    // FIXME: double borders in some case, can't fix it w/o a class tho
    // FIXME: doesn't work on dark var
    background-color: mix($bg_color, $borders_color, 70%);

    // this is the shading of the header behind the tabs
    .frame & {
      border: 1px solid $borders_color;
      &.top { border-bottom-width: 0; }
      &.bottom { border-top-width: 0; }
      &.right { border-left-width: 0; }
      &.left { border-right-width: 0; }
      &:backdrop { border-color: $backdrop_borders_color; }
    }

    &.top {
      box-shadow: $_header_shade,
                  inset 0 -1px $borders_color; // border
      &:backdrop { box-shadow: inset 0 -1px $backdrop_borders_color; }
      & tab {
        padding: $vt_vpadding $vt_hpadding;
        border-bottom-width: $tab_indicator_size;
        &.reorderable-page {
          padding-left: 12px;  // for a nicer close button
          padding-right: 12px; // placement
          border-left-width: 1px;
          border-right-width: 1px;
        }
      }
    }
    &.bottom {
      box-shadow: $_header_shade,
                  inset 0 1px $borders_color;
      &:backdrop { box-shadow: inset 0 1px $backdrop_borders_color; }
      & tab {
        padding: $vt_vpadding $vt_hpadding;
        border-top-width: $tab_indicator_size;
        &.reorderable-page {
          padding-left: 12px;  // for a nicer close button
          padding-right: 12px; // placement
          border-left-width: 1px;
          border-right-width: 1px;
        }
      }
    }
    &.right {
      box-shadow: $_header_shade,
                  inset 1px 0 $borders_color;
      &:backdrop { box-shadow: inset 1px 0 $backdrop_borders_color; }
      & tab {
        padding: $ht_vpadding $ht_hpadding;
        border-left-width: $tab_indicator_size;
        &.reorderable-page {
          border-bottom-width: 1px;
          border-top-width: 1px;
        }
      }
    }
    &.left {
      box-shadow: $_header_shade,
                  inset -1px 0 $borders_color;
      &:backdrop { box-shadow: inset -1px 0 $backdrop_borders_color; }
      & tab {
        padding: $ht_vpadding $ht_hpadding;
        border-right-width: $tab_indicator_size;
        &.reorderable-page {
          border-bottom-width: 1px;
          border-top-width: 1px;
        }
      }
    }
    &:backdrop {
      // same color as backdrop pushed button
      background-color: $backdrop_dark_fill;
      box-shadow: none;
    }
    &.top, &.bottom {
      & tabs arrow.up { -gtk-icon-source: -gtk-icontheme('pan-end-symbolic'); }
      & tabs arrow.down { -gtk-icon-source: -gtk-icontheme('pan-start-symbolic'); }
    }
    &.left, &.right {
      & tabs arrow.up { -gtk-icon-source: -gtk-icontheme('pan-down-symbolic'); }
      & tabs arrow.down { -gtk-icon-source: -gtk-icontheme('pan-up-symbolic'); }
    }
    & tabs arrow {
      color: $insensitive_fg_color;
      &:hover { color: mix($fg_color, $insensitive_fg_color, 50%); }
      &:active { color: $fg_color; }
      &:insensitive { color: transparentize($insensitive_fg_color,0.7); }
      &:backdrop { color: transparentize($backdrop_fg_color,0.6); }
      &:backdrop:insensitive { color: $backdrop_insensitive_color; }
    }
  }

  & tab {
    border-width: 0;
    border-style: solid;
    border-color: transparent;
    background-color: transparent;

    outline-offset: 0;

    //here's the interesting stuff
    &:hover {
      border-color: $borders_color;
    }
    &:active, &:backdrop:active {
      border-color: $selected_bg_color;
    }
    &:backdrop {
      background-color: transparent;
      border-color: transparent;
    }
    @each $_tab, $_border in (top, bottom),
                             (bottom, top),
                             (left, right),
                             (right, left) {
      .#{$_tab} &.reorderable-page {
        border-color: transparent;
        &:hover {
          border-color: transparentize($borders_color,0.7);
          border-#{$_border}-color: $borders_color;
          background-color: transparentize($bg_color,0.8);
        }
        &:active {
          background-color: transparentize($bg_color,0.5);
          border-color: transparentize($borders_color,0.5);
          border-#{$_border}-color: $selected_bg_color;
          &:hover { background-color: transparentize($bg_color,0.3); }
          &:backdrop {
            border-color: $backdrop_borders_color;
            background-color: $backdrop_bg_color;
            border-#{$_border}-color: $selected_bg_color;
          }
        }
        &:backdrop {
          border-color: transparent;
          background-color: transparent;
        }
      }
    }
    & label { //tab text
      padding: 0 2px; // needed for a nicer focus ring
      font-weight: bold;
      color: $insensitive_fg_color;
      &:backdrop {
        color: mix($backdrop_fg_color, $backdrop_insensitive_color, 50%);
      }
    }
    &:hover label {
      // prelight tab text
      color: mix($fg_color, $insensitive_fg_color, 50%);
      &:backdrop { // FIXME, it's the same as .label:backdrop up here
        color: mix($backdrop_fg_color, $backdrop_insensitive_color, 50%);
      }
    }
    &:active label {
      // active tab text
      color: $fg_color;
      &:backdrop { color: $backdrop_fg_color; }
    }
    button { //tab close button
      padding: 0;
      border: 1px solid transparent;
      @extend %undecorated_button;
      -gtk-icon-shadow: none;
      transition: none;
      color: transparentize($fg_color,0.7);
      &:hover {
        color:  $fg_color;
        @include button(hover, $edge:none);
        background-image: none;
        box-shadow: none;
      }
      &:active {
        @include button(active, $edge:none);
      }
      &:backdrop {
        color: transparentize($backdrop_fg_color,0.7);
        border-color: transparent;
      }
      & > image { // this is a hack which makes tabs grow
        padding: 2px;
      }
    }
  }
}

/**************
 * Scrollbars *
 **************/

scrollbar {
  @at-root * {
    -GtkRange-slider-width: 13;
    -GtkRange-trough-border: 0;
    -GtkScrollbar-has-backward-stepper: false;
    -GtkScrollbar-has-forward-stepper: false;
    -GtkScrollbar-min-slider-length: 42; // minimum size for the slider.
                                         // sadly can't be in '.slider'
                                         // where it belongs
    -GtkRange-stepper-spacing: 0;
    -GtkRange-trough-under-steppers: 1;
  }

  $_slider_margin: 3px;
  $_slider_fine_tune_margin: 4px;

  button {
    border: none;
  }

  &.overlay-indicator {
    &:not(.dragging):not(.hovering) { // Overlay scrolling indicator
      opacity: 0.4;

      -GtkRange-slider-width: 5px;

      slider {
        margin: 0;
        background-color: $fg_color;
        border: 1px solid if($variant==light, white, black);
        background-clip: padding-box;
      }

      & trough {
        border-style: none;
        background-color: transparent;
      }

      // w/o the following margin tweaks the slider shrinks when hovering/dragging
      &.vertical slider {
        margin-top: $_slider_margin - 1px;
        margin-bottom: $_slider_margin - 1px;
      }

      &.horizontal slider {
        margin-left: $_slider_margin - 1px;
        margin-right: $_slider_margin - 1px;
      }

    }

    &.dragging,
    &.hovering { opacity: 0.7; }
  }

  // trough coloring
  trough {
    background-color: $scrollbar_bg_color;
    border: 1px none $borders_color;

    &:backdrop {
      background-color: $backdrop_scrollbar_bg_color;
      border-color: $backdrop_borders_color;
    }
  }

  // slider coloring
  slider {
    background-color: mix($fg_color, $bg_color, 60%);

    &:hover { background-color: mix($fg_color, $bg_color, 80%); }

    &:prelight:active { background-color: if($variant=='light', darken($selected_bg_color, 10%), lighten($selected_bg_color, 10%));}

    &:backdrop { background-color: mix($backdrop_fg_color, $backdrop_bg_color, 40%); }

    &:insensitive {
      background-color: transparent;
    }
  }


  // sizing
  slider {
    border-radius: 100px;
    margin: $_slider_margin;
  }

  &.fine-tune slider { margin: $_slider_fine_tune_margin; }

  &.vertical {

    slider {
      margin-left: 1px + $_slider_margin;

      &:dir(rtl) {
        margin-left: $_slider_margin;
        margin-right: 1px + $_slider_margin;
      }
    }

    &.fine-tune slider {
      margin-left: 1px + $_slider_fine_tune_margin;

      &:dir(rtl) {
        margin-left: $_slider_fine_tune_margin;
        margin-right: 1px + $_slider_fine_tune_margin;
      }
    }

    trough {
      border-left-style: solid;

      &:dir(rtl) {
        border-left-style: none;
        border-right-style: solid;
      }
    }
  }

  &.horizontal {

    slider { margin-top: 1px + $_slider_margin; }

    &.fine-tune slider { margin-top: 1px + $_slider_fine_tune_margin; }

    trough { border-top-style: solid; }
  }
}

/**********
 * Switch *
 **********/

switch {
  font-weight: bold;
  font-size: smaller;
  outline-offset: -4px;
  box-shadow: inset 0 1px transparentize(black, 0.9), // needs to be set here
              _widget_edge();                         // otherwise it gets
                                                      // clipped
  // similar to the .scale
  border: 1px solid $borders_color;
  border-radius: 3px;
  color: $fg_color;
  background-image: linear-gradient(to bottom, mix($bg_color, $borders_color, 60%));
  text-shadow: 0 1px transparentize(black, 0.9);
  &:active {
      color: white;
      border-color: $selected_borders_color;
      background-color: $selected_bg_color;
      background-image: none;
      box-shadow: _widget_edge();
      text-shadow: 0 1px transparentize($selected_borders_color, 0.5),
                   0 0 2px transparentize(white, 0.4);
  }
  &:insensitive {
      color: $insensitive_fg_color;
      border-color: $borders_color;
      background-image: none;
      background-color: $insensitive_bg_color;
      box-shadow: _widget_edge();
      text-shadow: none;
  }
  &:backdrop {
      color: $backdrop_fg_color;
      border-color: $backdrop_borders_color;
      background-image: linear-gradient(to bottom, $backdrop_dark_fill);
      box-shadow: none;
      text-shadow: none;
      &:active {
        @if $variant == 'light' { color: $backdrop_bg_color; }
        border-color: if($variant == 'light', $selected_bg_color,
                                              $selected_borders_color);
        background-image: linear-gradient(to bottom, $selected_bg_color);
        box-shadow: none;
      }
  }
  &:insensitive {
        color: $backdrop_insensitive_color;
        border-color: $backdrop_borders_color;
        background-image: none;
        background-color: $insensitive_bg_color;
  }
  slider {
    margin: -1px;
    min-width: 45px;
    min-height: 27px;
    border: 1px solid;
    border-radius: 3px;
    @include button(normal);
    box-shadow: inset 0 1px if($variant=='light', white,
                               transparentize(white, 0.85)),
                inset 0 -2px transparentize($bg_color, 0.4),
                inset 0 -1px mix($bg_color, $borders_color, 50%);
  }
  &:hover slider {
    @include button(hover);
    box-shadow: inset 0 1px if($variant=='light', white,
                               transparentize(white, 0.85)),
                inset 0 -2px transparentize($bg_color, 0.4),
                inset 0 -1px mix($bg_color, $borders_color, 50%);
  }
  &:active slider { border: 1px solid $selected_borders_color; }

  &:insensitive slider { @include button(insensitive, $edge:none); }

  &:backdrop {
    slider {
      @include button(backdrop);
      box-shadow: none;
    }

    &:active slider { border-color: if($variant == 'light', $selected_bg_color, $selected_borders_color); }

    &:insensitive slider {
      @include button(backdrop-insensitive);
      box-shadow: none;
    }
  }
  row:selected & {
    @if $variant == 'light' {
      box-shadow: none;
      border-color: $selected_borders_color;
      &:backdrop { border-color: $selected_borders_color; }
      &.slider:dir(rtl) { border-left-color: $borders_color; }
      &.slider:dir(ltr) { border-right-color: $borders_color; }
      &.slider,
      &.slider:active { border-color: $selected_borders_color; }
    }
  }
}

/*************************
 * Check and Radio items *
 *************************/

// draw regular check and radio items using our PNG assets
// all assets are rendered from assets.svg. never add pngs directly

@each $w,$a in ('check', 'checkbox'),
               ('radio','radio') {

  //standard checks and radios
  @each $s,$as in ('','-unchecked'),
                  (':hover', '-unchecked-hover'),
                  (':active', '-unchecked-active'),
                  (':insensitive','-unchecked-insensitive'),
                  (':backdrop', '-unchecked-backdrop'),
                  (':backdrop:insensitive', '-unchecked-backdrop-insensitive'),
                  (':inconsistent', '-mixed'),
                  (':inconsistent:hover', '-mixed-hover'),
                  (':inconsistent:selected', '-mixed-active'),
                  (':inconsistent:backdrop', '-mixed-backdrop'),
                  (':inconsistent:insensitive', '-mixed-insensitive'),
                  (':inconsistent:insensitive:backdrop', '-mixed-backdrop-insensitive'),
                  (':checked', '-checked'),
                  (':checked:insensitive','-checked-insensitive'),
                  (':checked:hover', '-checked-hover'),
                  (':checked:active', '-checked-active'),
                  (':backdrop:checked', '-checked-backdrop'),
                  (':backdrop:checked:insensitive', '-checked-backdrop-insensitive') {
    #{$w}#{$s} {
      -gtk-icon-source: -gtk-scaled(url("assets/#{$a}#{$as}#{$asset_suffix}.png"),
                                    url("assets/#{$a}#{$as}#{$asset_suffix}@2.png"));
      -gtk-icon-shadow: if(str-index($s,"backdrop"), none, 0 1px 0 $borders_edge); //no edge highlight for :backdrop
      & button.flat { -gtk-icon-shadow: none; }
    }
    @if $variant == 'light' {
      // the borders of the light variant versions of checks and radios are
      // too similar in luminosity to the selected background color, hence
      // we need special casing.
      .view #{$w}#{$s}:selected,
      row:selected #{$w}#{$s} {
        -gtk-icon-source: -gtk-scaled(url("assets/selected-#{$a}#{$as}#{$asset_suffix}.png"),
                                      url("assets/selected-#{$a}#{$as}#{$asset_suffix}@2.png"));
      }
    }
  }

  //menu
  menu menuitem #{$w} {
    color: mix($fg_color, $bg_color, 70%);
    -gtk-icon-source: -gtk-icontheme('#{$a}-symbolic');
    -gtk-icon-shadow: none;
    &:hover, &:insensitive {
      -gtk-icon-source: -gtk-icontheme('#{$a}-symbolic');
      -gtk-icon-shadow: none;
    }
    &:checked, &:checked:hover, &:checked:insensitive {
      -gtk-icon-source: -gtk-icontheme('#{$a}-checked-symbolic');
      -gtk-icon-shadow: none;
    }
    &:inconsistent, &:inconsistent:hover, &:inconsistent:insensitive {
      -gtk-icon-source: -gtk-icontheme('#{$a}-mixed-symbolic');
      -gtk-icon-shadow: none;
    }
    &:hover { color: $selected_fg_color; }
    &:insensitive { color: mix($insensitive_fg_color, $bg_color, 50%); }
  }
}

//treeview and rows
.view.check, .view.radio,
row .check, row .radio {
  -gtk-icon-shadow: none;
  &:selected, &:hover { -gtk-icon-shadow: none; }
}

//selection-mode
@each $s,$as in ('','-selectionmode'),
                  (':hover', '-hover-selectionmode'),
                  (':active', '-active-selectionmode'),
                  (':backdrop', '-backdrop-selectionmode'),
                  (':checked', '-checked-selectionmode'),
                  (':checked:hover', '-checked-hover-selectionmode'),
                  (':checked:active', '-checked-active-selectionmode'),
                  (':backdrop:checked', '-checked-backdrop-selectionmode') {
  .view.content-view.check#{$s}:not(list) {
    -gtk-icon-shadow: none;
    -gtk-icon-source: -gtk-scaled(url("assets/checkbox#{$as}.png"),
                                    url("assets/checkbox#{$as}@2.png"));
    background-color: transparent;
  }
}

checkbutton.text-button, radiobutton.text-button {
  // this is for a nice focus on check and radios text
  padding: 1px 2px 4px;
  outline-offset: 0;
  &:insensitive,
  &:insensitive:active,
  &:insensitive:inconsistent {
    // set insensitive color, which is overriden otherwise
    color: $insensitive_fg_color;
    &:backdrop { color: $backdrop_insensitive_color; }
  }
}

radiobutton radio,
checkbutton check {
  min-width: 16px;
  min-height: 16px;
  margin: 0 2px 0 2px;
  &:only-child {
    margin: 0;
  }
}

/************
 * GtkScale *
 ************/

%scale_trough {
  border: 1px solid $borders_color;
  border-radius: 3px;
  background-color: $dark_fill;
  box-shadow: inset 1px 1px transparentize(black, 0.9),
              _widget_edge();

  &:insensitive {
    background-color: $insensitive_bg_color;
    box-shadow: _widget_edge();
  }

  &:backdrop {
    background-color: $backdrop_dark_fill;
    border-color: $backdrop_borders_color;
    box-shadow: none;
    &:insensitive { background-color: $insensitive_bg_color; }
  }

  // ...on selected list rows
  row:selected & {
    box-shadow: none;

    &, &:insensitive { border-color: $selected_borders_color; }
  }

  // OSD
  .osd & {
    border-color: $osd_borders_color;
    background-color: transparentize($osd_borders_color, 0.2);
    box-shadow: none;
    outline-color: transparentize($osd_fg_color, 0.8);

    &:insensitive { background-color: $osd_insensitive_bg_color; }
  }
}

%scale_highlight {
  border: 1px solid $selected_borders_color;
  border-radius: 3px;
  background-color: $selected_bg_color;

  &:insensitive {
    background-color: transparent;
    border-color: transparent;
  }

  &:backdrop {
    border-color: if($variant=='light', $selected_bg_color,
                                        $selected_borders_color);
    &:insensitive {
      background-color: transparent;
      border-color: transparent;
    }
  }

  // ...on selected list rows
  row:selected & { &, &:insensitive { border-color: $selected_borders_color; } }

  // OSD
  .osd & {
    border-color: $osd_borders_color;
    &:insensitive { border-color: transparent; }
  }
}

scale {
  -GtkScale-slider-length: 20;
  -GtkRange-slider-width: 26;
  -GtkRange-trough-border: 2;

  outline-offset: -10px;
  -gtk-outline-radius: 6px;

  &.fine-tune {
    outline-offset: -8px;
    -gtk-outline-radius: 8px;

    trough {
      margin: 11px;
      &, fill, highlight { border-radius: 4px; }
    }
  }

  trough { margin: 13px; }

  &.horizontal slider { margin: 3px 0; }
  &.vertical slider { margin: 0 3px; }

  // the backing bit
  trough { @extend %scale_trough; }

  // the colored part of the backing bit
  highlight { @extend %scale_highlight; }

  // this is another differently styled part of the backing bit, the most relevant use case is for example
  // in media player to indicate how much video stream as been cached
  fill {
    @extend %scale_trough;
    &, &:backdrop {
      background-color: $borders_color;
      box-shadow: none;
    }

    &:insensitive {
      &, &:backdrop {
        border-color: transparent;
        background-color: transparent;
      }
    }

    // OSD
    .osd & {
      background-color: mix($osd_fg_color, $osd_borders_color, 25%);
      &:insensitive {
        &, &:backdrop {
          border-color: transparent;
          background-color: transparent;
        }
      }
    }
  }

  slider {
    // FIXME: scale-has-marks-* missing
    $_slider_edge_color: transparentize(black, 0.9);
    @include button(normal, $edge: $_slider_edge_color);
    border: 1px solid darken($borders_color, 3%);
    border-radius: 100%;

    &:hover { @include button(hover, $edge: $_slider_edge_color); }

    &:active { border-color: $selected_borders_color; }

    &:insensitive { @include button (insensitive); }

    &:backdrop {
      @include button(backdrop);
      &:insensitive { @include button(backdrop-insensitive); }
    }

    // ...on selected list rows
    row:selected & { &, &:insensitive { border-color: $selected_borders_color; } }

    // OSD
    .osd & {
      @include button(osd);
      border-color: darken($osd_borders_color, 3%);
      background-color: opacify($osd_bg_color, 1); // solid background needed here

      &:hover { @include button(osd-hover); }

      &:active { @include button(osd-active); }

      &:insensitive { @include button(osd-insensitive); }

      &:backdrop {
        @include button(osd-backdrop);

        &:insensitive { @include button(osd-backdrop-insensitive); }
      }
    }
  }

  marks { color: gtkalpha(currentColor, 0.4); }

  // *WARNING* scale with marks madness following

  // FIXME: OSD and selected list rows missing, I don't feel like adding the other 144 assets needed for those...
  $suffix: if($variant == 'light', '', '-dark');

  @each $dir_class, $dir_infix in ('', 'horz'),
                                  ('.vertical', 'vert') {
    @each $marks_infix, $nth_child in ('scale-has-marks-above', ':last-child:not(:only-child)'),
                                      ('scale-has-marks-below', ':first-child:not(:only-child)') {

      &#{$dir_class} {
        @each $state, $state_infix in ('', ''),
                                 (':hover', '-hover'),
                                 (':active', '-active'),
                                 (':insensitive', '-insensitive'),
                                 (':backdrop', '-backdrop'),
                                 (':backdrop:insensitive', '-backdrop-insensitive') {

          &.fine-tune trough#{$nth_child} {}

          trough#{$nth_child} {
            slider{
              margin: 0;
              &#{$state} {
                $_scale_asset: 'assets/slider-#{$dir_infix}-#{$marks_infix}#{$state_infix}#{$suffix}';
                // @warn $_file_name; // uncomment for debuggin purpose...
                border-style: none;
                border-radius: 0;

                background-image: -gtk-scaled(url('#{$_scale_asset}.png'), url('#{$_scale_asset}@2.png'));

                $_scale_slider_bg_pos: bottom;
                @if $dir_infix == 'horz' {
                  @if $marks_infix == 'scale-has-marks-above' { $_scale_slider_bg_pos: top; }
                }
                @else {
                  @if $marks_infix == 'scale-has-marks-above' { $_scale_slider_bg_pos: left; }
                  @else { $_scale_slider_bg_pos: right; }
                }

                background-position: $_scale_slider_bg_pos;
                background-repeat: no-repeat;
                box-shadow: none;
              }
            }
          }
        }
      }
    }
  }
}


/*****************
 * Progress bars *
 *****************/

progressbar {
  // sizing
  &.horizontal {
    trough,
    progress { min-height: 2px; } // FIXME: should be 4px, but looks like currently gtk+ consider borders
  }

  &.vertical {
    trough,
    progress { min-width: 2px; } // FIXME: should be 4px, but looks like currently gtk+ consider borders
  }

  &.horizontal progress { margin: 0 -1px; } // the progress node is positioned after the trough border
  &.vertical progress { margin: -1px 0; }   // this moves it over it.


  // FIXME: insensitive state missing and some other state should be set probably
  font-size: smaller;
  color: transparentize($fg_color, 0.6);

  box-shadow: _widget_edge();      // needs to be set here;
  &:backdrop { box-shadow: none; }

  trough {
    @extend %scale_trough;
  }

  &:backdrop trough { @extend %scale_trough:backdrop; } // looks like states are not passed to the trough component here

  progress {
    @extend %scale_highlight;
    border-radius: 1.5px;
    &.left {
      border-top-left-radius: 2px;
      border-bottom-left-radius: 2px;
    }
    &.right {
      border-top-right-radius: 2px;
      border-bottom-right-radius: 2px;
    }
    &.top {
      border-top-right-radius: 2px;
      border-top-left-radius: 2px;
    }
    &.bottom {
      border-bottom-right-radius: 2px;
      border-bottom-left-radius: 2px;
    }
  }

  &:backdrop progress { @extend %scale_highlight:backdrop; } // states not passed here as well

  &.osd {
    min-width: 3px;
    min-height: 3px;
    trough {
      border-style: none;
      border-radius: 0;
      background-color: transparent;
      box-shadow: none;
    }

    progress {
      border-style: none;
      border-radius: 0;
    }
  }
}

/*************
 * Level Bar *
 *************/

levelbar {
  box-shadow: _widget_edge(); // needs to be set here to avoid clipping
  -GtkLevelBar-min-block-width: 34;
  -GtkLevelBar-min-block-height: 3;
  &.vertical {
    -GtkLevelBar-min-block-width: 3;
    -GtkLevelBar-min-block-height: 34;
  }
  & trough {
    border: 1px solid;
    padding: 2px;
    border-radius: 3px;
    @include entry(normal);
    &:backdrop {
      @include entry(backdrop);
    }
  }
  &.horizontal.discrete block { margin: 0 1px; }
  &.vertical.discrete block { margin: 1px 0; }
  & block:not(.empty) {
    border: 1px solid if($variant=='light', darken($selected_bg_color,10%),
                                              darken($selected_bg_color,5%));
    background-color: $selected_bg_color;
    box-shadow: 0 1px transparentize(black, 0.9);
    border-radius: 1px;
    &:backdrop {
      border-color: $selected_bg_color;
      box-shadow: none;
    }
  }
  & block.low {
    border-color: darken($warning_color,10%);
    background-color: $warning_color;
    &:backdrop { border-color: $warning_color; };
  }
  & block.high {
    border-color: darken($selected_bg_color,10%);
    background-color: $selected_bg_color;
    &:backdrop { border-color: $selected_bg_color; }
  }
  & block.full {
    border-color: darken($success_color,10%);
    background-color: $success_color;
    &:backdrop { border-color: $success_color; };
  }
  & block.empty {
    border: 1px solid if($variant=='light', darken($selected_bg_color,10%),
                                              darken($selected_bg_color,5%));
    border-radius: 1px;
    background-color: transparent;
    border-color: if($variant=='light', transparentize($fg_color,0.8),
                       transparentize($fg_color,0.9));
    box-shadow: none;
    &:backdrop { border-color: transparentize($backdrop_fg_color,0.85); }
  }
}


/**********
 * Frames *
 **********/
frame border,
.frame {
  box-shadow: none;
  margin: 0;
  padding: 0;
  border-radius: 0;
  border: 1px solid $borders_color;
  &.flat { border-style: none; }
  &:backdrop { border-color: $backdrop_borders_color; }
}

paper {
  border: 1px solid $borders_color;
  background: white;
  padding: 0;
  &:backdrop { border-color: $backdrop_borders_color; }
}

actionbar box {
  padding: 6px;
  border-width: 1px 0 0;
}

placessidebar,
scrolledwindow {
  viewport.frame { // avoid double borders when viewport inside scrolled window
    border-style: none;
  }
  // This is used when content is touch-dragged past boundaries.
  // draws a box on top of the content, the size changes programmatically.
  overshoot {
    &.top {
      @include overshoot(top);
      &:backdrop { @include overshoot(top, backdrop); }
    }
    &.bottom {
      @include overshoot(bottom);
      &:backdrop { @include overshoot(bottom, backdrop); }
    }
    &.left {
      @include overshoot(left);
      &:backdrop { @include overshoot(left, backdrop); }
    }
    &.right {
      @include overshoot(right);
      &:backdrop { @include overshoot(right, backdrop); }
    }
  }

  // Overflow indication, works similarly to the overshoot, the size if fixed tho.
  undershoot {
    &.top { @include undershoot(top); }
    &.bottom { @include undershoot(bottom); }
    &.left { @include undershoot(left); }
    &.right { @include undershoot(right); }
  }

  junction { // the small square between two scrollbars
    border-color: transparent;
    // the border image is used to add the missing dot between the borders, details, details, details...
    border-image: linear-gradient(to bottom, $borders_color 1px, transparent 1px) 0 0 0 1 / 0 1px stretch;
    background-color: $scrollbar_bg_color;

    &:dir(rtl) { border-image-slice: 0 1 0 0; }

    &:backdrop {
      border-image-source: linear-gradient(to bottom, $backdrop_borders_color 1px, transparent 1px);
      background-color: $backdrop_scrollbar_bg_color;
    }
  }
}

//vbox and hbox separators
separator {
  // always disable separators
  // -GtkWidget-wide-separators: true;
  background: transparentize(black, 0.9);
  min-width: 1px;
  min-height: 1px;

  // Font and File button separators
  button.file &.vertical,
  button.font &.vertical {
    // always disable separators
    -GtkWidget-wide-separators: true;
  }
}

/*********
 * Lists *
 *********/

list {
  background-color: $base_color;
  border-color: $borders_color;
  &:backdrop {
    background-color: $backdrop_base_color;
    border-color: $backdrop_borders_color;
  }
  row {
    padding: 2px;
  }
}

row.activatable {
  &.has-open-popup, // this is for indicathing which row generated a popover see https://bugzilla.gnome.org/show_bug.cgi?id=754411
  &:hover { background-color: if(variant == light, transparentize($fg_color, 0.9), transparentize($fg_color, 0.95)); }

  &:active { box-shadow: inset 0 2px 2px -2px transparentize(black, 0.8); }

  &:backdrop:hover { background-color: transparent; }

  &:selected {
    &:active { box-shadow: inset 0 2px 3px -1px transparentize(black, 0.5); }

    &.has-open-popup,
    &:hover { background-color: mix($fg_color, $selected_bg_color, 10%); }

    &:backdrop { background-color: $selected_bg_color; }
  }
}

row:selected {
  @extend %selected_items;
  button {
    @include button(normal, $edge:none);
    @if $variant == 'light' { border-color: $selected_borders_color; }
    &.flat {
      @include button(undecorated, $edge:none);
      color: $selected_fg_color;
    }
    &:hover {
      @include button(hover, $edge:none);
      @if $variant == 'light' { border-color: $selected_borders_color; }
    }
    &:active, &:checked {
      @include button(active, $edge:none);
      @if $variant == 'light' { border-color: $selected_borders_color; }
    }
    &:backdrop, &.flat:backdrop {
      @include button(backdrop, $edge:none);
      @if $variant == 'light' { border-color: $selected_borders_color; }
      &:active, &:checked {
        @include button(backdrop-active, $edge:none);
        @if $variant == 'light' { border-color: $selected_borders_color; }
      }
      &:insensitive {
        @include button(backdrop-insensitive, $edge:none);
        @if $variant == 'light' { border-color: $selected_borders_color; }
        &:active, &:checked {
          @include button(backdrop-insensitive-active, $edge:none);
          @if $variant == 'light' { border-color: $selected_borders_color; }
        }
      }
    }
    &.flat:backdrop {
      @include button(undecorated);
      color: if($variant=='light', $backdrop_base_color, $backdrop_fg_color);
    }
    &:insensitive {
      @include button(insensitive, $edge:none);
      @if $variant == 'light' { border-color: $selected_borders_color; }
      &:active, &:checked { @include button(insensitive-active, $edge:none); }
    }
    //FIXME: make placeholder with buttons w/o edge to be extended around
    //       istead of repeating everytime this stuff.
  }
}

// transition
row {
  transition: all 150ms $ease-out-quad;
  &:hover { transition: none; }
}


/*********************
 * App Notifications *
 *********************/

.app-notification,
.app-notification.frame {
  @extend %osd;
  padding: 10px;
  border-radius: 0 0 5px 5px;
  background-color: $osd_bg_color;
  background-image: linear-gradient(to bottom, transparentize(black, 0.8),
                                               transparent 2px);
  background-clip: padding-box;
  &:backdrop { background-image: none; }

  button { @extend %osd_button; }
  border { border: none; }
}

/*************
 * Expanders *
 *************/

expander {
  & arrow {
    min-width: 16px;
    min-height: 16px;
    -gtk-icon-source: -gtk-icontheme('pan-end-symbolic');
    &:dir(rtl) { -gtk-icon-source: -gtk-icontheme('pan-end-symbolic-rtl'); }
    &:hover { color: lighten($fg_color,30%); } //only lightens the arrow
    &:checked { -gtk-icon-source: -gtk-icontheme('pan-down-symbolic'); }
  }
}

/************
 * Calendar *
 ***********/
calendar {
  color: $text_color;
  border: 1px solid $borders_color;

  &:selected {
    @extend .view:selected;
  }

  &.header {
    border: 1px solid transparentize(black, 0.9);
    border-radius: 0;

    &:backdrop { border-color: transparentize(black, 0.9); }
  }

  &.button {
    @extend %undecorated_button;
    color: transparentize($fg_color, 0.55);

    &:hover {
      @extend %undecorated_button;
      color: $fg_color;
    }

    &:backdrop {
      @extend %undecorated_button;
      color: transparentize($backdrop_fg_color,0.55);
    }

    &:insensitive {
      @extend %undecorated_button;
      color:  transparentize($insensitive_fg_color,0.55);
    }
  }

  &:inconsistent, &:inconsistent:backdrop { color: gtkalpha(currentColor, 0.55); }
  &.highlight, &.highlight:backdrop {
    font-size: smaller;
    color: $fg_color;
  }


  &:backdrop {
    color: $backdrop_text_color;
    border-color: $backdrop_borders_color;
  }
}

/***********
 * Dialogs *
 ***********/

messagedialog .dialog-action-area button {
  padding: 8px;
}

messagedialog { // Message Dialog styling
  @if $variant==light {
    // the bright variant as a slightly darker bg which in this case clashes with the window decoration, overriding
    &.background { background-color: $bg_color; }
  }

  .titlebar {
    border-style: none;
    box-shadow: inset 0 1px $borders_edge;
  }
  &.csd { // rounded bottom border styling for csd version
    &.background {
      // bigger radius for better antialiasing
      border-bottom-left-radius: 9px;
      border-bottom-right-radius: 9px;
    }
    .dialog-action-area button {
      padding: 12px;
      border-radius: 0;
      @include button(normal, $edge:none);
      @extend %middle_button;
      &:hover {
        @include button(hover, $edge:none);
        @extend %middle_button;
      }
      &:active {
        @include button(active, $edge:none);
        @extend %middle_button;
      }
      &:insensitive {
        @include button(insensitive, $edge:none);
        @extend %middle_button;
      }
      &:backdrop {
        @include button(backdrop, $edge:none);
        @extend %middle_button;
      }
      &:backdrop:insensitive {
        @include button(backdrop-insensitive, $edge:none);
        @extend %middle_button;
      }
      @each $b_type, $b_color in (suggested-action, $selected_bg_color),
                                 (destructive-action, $destructive_color) {
        &.#{$b_type} {
          @include button(normal, $b_color, white, $edge:none);
          @extend %middle_button;
          &:hover {
            @include button(hover, $b_color, white, $edge:none);
            @extend %middle_button;
          }
          &:active {
            @include button(active, $b_color, white, $edge:none);
            @extend %middle_button;
          }
          &:backdrop {
            @include button(backdrop, $b_color, white, $edge:none);
            @extend %middle_button;
            &:insensitive {
              @include button(backdrop-insensitive, $edge:none);
              @extend %middle_button;
            }
          }
          &:insensitive {
            @include button(insensitive, $edge:none);
            @extend %middle_button;
          }
        }
      }
      &:first-child{ @extend %first_button; }
      &:last-child { @extend %last_button; }
    }
    %middle_button {
      border-left-style: solid;
      border-right-style: none;
      border-bottom-style: none;
    }
    %last_button {
      border-bottom-right-radius: 7px;
      -gtk-outline-bottom-right-radius: 5px;
    }
    %first_button {
      border-left-style: none;
      border-bottom-left-radius: 7px;
      -gtk-outline-bottom-left-radius: 5px;
    }
  }
}

GtkFileChooserDialog {
  .dialog-action-box {
    border-top: 1px solid $borders_color;
    &:backdrop { border-top-color: $backdrop_borders_color; }
  }
}

/***********
 * Sidebar *
 ***********/

.sidebar {
  border: none;
  background-color: mix($bg_color, $base_color, 50%);

  &:backdrop {
    background-color: $backdrop_sidebar_bg_color;
  }

  :selected {
    @extend %selected_items;
  }
}

stacksidebar {
  & row {
    padding: 10px 4px;
    & > label {
      padding-left: 6px;
      padding-right: 6px;
    }
    &.needs-attention > label {
      @extend %needs_attention;
      background-size: 6px 6px, 0 0;
    }
  }
}

/****************
 * File chooser *
 ****************/

$_placesidebar_icons_opacity: 0.7;

placessidebar {
  row {
    // Needs overriding of the GtkListBoxRow padding
    padding: 0px;
    // Using margins/padding directly in the SidebarRow
    // will make the animation of the new bookmark row jump
    & > revealer {
      padding: 4px 14px 4px 12px;
    }
    & image.sidebar-icon {
      opacity: $_placesidebar_icons_opacity; // dim the device icons
      &:dir(ltr) { padding-right: 8px; }
      &:dir(rtl) { padding-left: 8px; }
    }
    & label.sidebar-label {
      &:dir(ltr) { padding-right: 2px; }
      &:dir(rtl) { padding-left: 2px; }
    }
    @at-root button.sidebar-button {
      padding: 5px;
      @extend button.flat;
      border-radius: 100%;
      -gtk-outline-radius: 100%;
      &:not(:hover):not(:active) > image,
      &:backdrop > image { opacity: $_placesidebar_icons_opacity };
    }
  }

  // in the sidebar case it makes no sense to click the selected row
  row:selected:active { box-shadow: none; }

   // looks like the label doesn't get all the states so work around
  row:selected:insensitive label { @extend %selected_items:insensitive; }
  row:selected:backdrop:insensitive label { @extend %selected_items:backdrop:insensitive; }

  row.sidebar-placeholder-row {
    border: solid 1px $selected_bg_color;
  }

  row.sidebar-new-bookmark-row {
    color: $selected_bg_color;
  }
}

placesview {
  .server-list-button > image {
    transition: 200ms $ease-out-quad;
    -gtk-icon-transform: rotate(0turn);
  }

  .server-list-button:checked > image {
    transition: 200ms $ease-out-quad;
    -gtk-icon-transform: rotate(-0.5turn);
  }

  row.activatable:hover {
    background-color: transparent;
  }
}

/*********
 * Paned *
 *********/

paned {
  separator {
    min-width: 1px;
    min-height: 1px;
    background-color: $borders_color;
    &:backdrop {
      background-color: $backdrop_borders_color;
    }
  }
  &:dir(ltr).horizontal separator {
    margin: 0 -8px 0 0;
    padding: 0 8px 0 0;
  }
  &:dir(rtl).horizontal separator {
    margin: 0 0 0 -8px;
    padding: 0 0 0 8px;
  }
  &.vertical separator {
    margin: 0 0 -8px 0;
    padding: 0 0 8px 0;
  }
  separator:selected {
    background-color: $selected_bg_color;
  }
  separator.wide {
    min-width: 5px;
    min-height: 5px;
    background-color: transparent;
    border-style: none solid;
    border-color: $borders_color;
    border-width: 1px;
  }
}


/**************
 * GtkInfoBar *
 **************/
infobar {
  border-style: none;
}

.info,
.question,
.warning,
.error {
  background-color: $selected_bg_color;
  color: $selected_fg_color;
  text-shadow: 0 1px darken($selected_bg_color, 10%);
  border-color: darken($selected_bg_color, 10%);
  button {
    // FIXME: extend selection mode buttons
    @include button(normal, $selected_bg_color, $selected_fg_color, none);
    &:hover {
      @include button(hover, $selected_bg_color, $selected_fg_color, none); }
    &:active {
      @include button(active, $selected_bg_color, $selected_fg_color, none); }
    &:insensitive {
      @include button(insensitive,$selected_bg_color,$selected_fg_color,none); }
    &:backdrop {
      @include button(backdrop, $selected_bg_color, $selected_fg_color, none);
      border-color: _border_color($selected_bg_color);
      &:insensitive {
        @include button(backdrop-insensitive, $selected_bg_color,
                        $selected_fg_color, none);
        border-color: _border_color($selected_bg_color);
      }
    }
  }
  & label:selected,
  & label:selected:focus,
  & label:selected:hover {
    background-color: darken($selected_bg_color, 10%);
  }
}

/************
 * Tooltips *
 ************/

tooltip {
  &.background {
    // background-color needs to be set this way otherwise it gets drawn twice
    // see https://bugzilla.gnome.org/show_bug.cgi?id=736155 for details.
    background-color: transparentize(black, 0.2);
    background-clip: padding-box;
    border: 1px solid $tooltip_borders_color; // this suble border is meant to
                                              // not make the tooltip melt with
                                              // very dark backgrounds
  }

  padding: 4px; /* not working */
  border-radius: 5px;
  box-shadow: none; // otherwise it gets inherited by windowframe.csd
  text-shadow: 0 1px black;
  // FIXME: we need a border or tooltips vanish on black background.
  decoration {
    background-color: transparent;
  }
  * { //Yeah this is ugly
    padding: 4px;
    background-color: transparent;
    color: white;
  }
}

/*****************
 * Color Chooser *
 *****************/

colorswatch {
  // This widget is made of two boxes one on top of the other, the lower box is colorswatch {} the other one
  // is colorswatch overlay {}, GtkColorSwatch has the programmatically set background, so most of the style
  // is applied to the overlay box.

  $_colorswatch_shadow: inset 0 1px transparentize(black, 0.9), _widget_edge();

  $_colorswatch_radius: 5px;

  box-shadow: $_colorswatch_shadow;

  // take care of colorswatches on selected elements
  :selected & {
    box-shadow: none;
    & overlay, & overlay:hover {
      border-color: $selected_fg_color;
    }
  }

  // we need to re-set the shadow here since it get axed by the previous bit
  &:selected { box-shadow: $_colorswatch_shadow; }

  // base color corners rounding
  // to avoid the artifacts caused by rounded corner anti-aliasing the base color
  // sports a bigger radius.
  // nth-child is needed by the custom color strip.
  // The :not() madness is needed since actually the overlay is selectable by GtkColorSwatch > .overlay
  // and GtkColorSwatch.overlay, I know it's weird, but this is gtk+, not a browser.
  &.top {
    border-top-left-radius: $_colorswatch-radius + 1px;
    border-top-right-radius: $_colorswatch-radius + 1px;
  }
  &.bottom {
    border-bottom-left-radius: $_colorswatch-radius + 1px;
    border-bottom-right-radius: $_colorswatch-radius + 1px;
  }
  &.left, &:first-child:not(overlay):not(.top) {
    border-top-left-radius: $_colorswatch-radius + 1px;
    border-bottom-left-radius: $_colorswatch-radius + 1px;
  }
  &.right, &:last-child:not(overlay):not(.bottom) {
    border-top-right-radius: $_colorswatch-radius + 1px;
    border-bottom-right-radius: $_colorswatch-radius + 1px;
  }
  &:only-child:not(overlay) { border-radius: $_colorswatch-radius + 1px; }

  // overlay corner rounding
  &.top > overlay {
    border-top-left-radius: $_colorswatch-radius;
    border-top-right-radius: $_colorswatch-radius;
  }
  &.bottom > overlay {
    border-bottom-left-radius: $_colorswatch-radius;
    border-bottom-right-radius: $_colorswatch-radius;
  }
  &:first-child:not(.top) > overlay {
    border-top-left-radius: $_colorswatch-radius;
    border-bottom-left-radius: $_colorswatch-radius;
  }
  &:last-child:not(.bottom) > overlay {
    border-top-right-radius: $_colorswatch-radius;
    border-bottom-right-radius: $_colorswatch-radius;
  }
  &:only-child > overlay { border-radius: $_colorswatch-radius; }

  // hover effect
  &.activatable:hover,
  &.activatable:hover:selected {
    background-image: linear-gradient(135deg, transparentize(white, 0.3),
                                              transparentize(white, 1) 50%);
    box-shadow: inset 0 1px transparentize(white, 0.6),
                inset 0 -1px if($variant == 'light', transparentize(black, 0.9), transparentize(black, 0.6));
  }
  &:backdrop,
  &:backdrop:selected
  &.dark:backdrop,
  &.dark:backdrop:selected {
    background-image: none;
    box-shadow: none;
  }

  // indicator and keynav outline colors
  &.dark {
    color: white;
    outline-color: transparentize(white, 0.5);
    border: 1px solid if($variant == 'light', transparentize(black, 0.7), $borders_color);
    &:hover { border-color: if($variant == 'light', transparentize(black, 0.5), black); }
    &:backdrop { color: transparentize(white, 0.7); }
  }
  &.light {
    color: black;
    outline-color: transparentize(black, 0.5);
    border: 1px solid if($variant == 'light', transparentize(black, 0.7), $borders_color);
    &:hover { border-color: if($variant == 'light', transparentize(black, 0.5), black); }
    &:backdrop { color: transparentize(black, 0.7); }
  }

  // border color
  & overlay,
  & overlay:selected {
    background: none;
    border: none;
  }

  // make the add color button looks like, well, a button
  &#add-color-button {
    border-style: solid; // the borders are drawn by the overlay for standard colorswatches to have them semi
    border-width: 1px;   // translucent on the colored background, here it's not necessary so they need to be set
    @include button(normal);
    &:hover { @include button(hover); }
    &:backdrop { @include button(backdrop); }
    overlay { @include button(undecorated); } // reset the overlay to not cover the button style underneat
  }
}


/********
 * Misc *
 ********/

//content view (grid/list)
.content-view {
  background-color: darken($bg_color,7%);
  &:hover { -gtk-icon-effect: highlight; }
  &:backdrop { background-color: darken($bg_color,7%); }
  & rubberband { @extend rubberband; }
}

.scale-popup {

   .osd & { @extend %osd; }

   .osd & button.flat {  //FIXME: quick hack, redo properly
     padding: 6px;
     border-style: none;
     border-radius: 5px;
   }

  button { // +/- buttons on GtkVolumeButton popup
    padding: 6px;
    &:hover {
      @extend %undecorated_button;
      background-color: transparentize($fg_color,0.9);
      border-radius: 5px;
    }
    &:backdrop,
    &:backdrop:hover,
    &:backdrop:insensitive { @extend %undecorated_button; }
  }
}

GtkScaleButton.button,
GtkVolumeButton.button {
  // I assume both are image-button *by default*
  // with the image-button/text-button classes automagically applied depending on the button child these selectors can be deleted.
  @extend .image-button;

  &.text-button { @extend button.text-button }
}

/**********************
 * Window Decorations *
 *********************/

decoration {
  border-radius: 7px 7px 0 0;
  // lamefun trick to get rounded borders regardless of CSD use
  border-width: 0px;

  // this needs to be transparent
  // see bug #722563
  $_wm_border: if($variant=='light', transparentize(black, 0.77), transparentize($borders_color, 0.1));
  $_wm_border_backdrop: if($variant=='light', transparentize(black, 0.82), transparentize($borders_color, 0.1));

  box-shadow: 0 3px 9px 1px transparentize(black, 0.5),
              0 0 0 1px $_wm_border; //doing borders with box-shadow

  // FIXME rationalize shadows

  /* this is used for the resize cursor area */
  margin: 10px;

  &:backdrop {
    /* the transparent shadow here is to enforce that the shadow extents don't
     * change when we go to backdrop, to prevent jumping windows
     */
    box-shadow: 0 2px 6px 2px transparentize(black, 0.8),
                0 3px 9px 1px transparent,
                0 0 0 1px $_wm_border_backdrop;
  }
  .tiled & {
    border-radius: 0;
  }
  .popup & {
    box-shadow: none;
  }
  // server-side decorations as used by mutter
  &.ssd {
    box-shadow: 0 0 0 1px $_wm_border; //just doing borders, wm draws actual shadows
  }
  .csd.popup & {
    border-radius: 0;
    box-shadow: 0 1px 2px transparentize(black, 0.8),
                0 0 0 1px transparentize($_wm_border,0.1);
  }
  tooltip.csd & {
    border-radius: 5px;
    box-shadow: none;
  }
  messagedialog.csd & {
    border-radius: 7px;
    box-shadow: 0 1px 2px transparentize(black, 0.8),
                  0 0 0 1px transparentize($_wm_border,0.1);
  }
  .solid-csd & {
    border-radius: 0;
    margin: 4px;
    background-color: $backdrop_bg_color;
    border: solid 1px $backdrop_borders_color;
    box-shadow: none;
  }
}

// Window Close button
headerbar button.titlebutton,
.titlebar button.titlebutton {
  @extend button;
  @extend button.flat;
  @extend .image-button;
  @include _button_text_shadow;
  &:backdrop { -gtk-icon-shadow: none; }
}

headerbar.selection-mode button.titlebutton,
.titlebar.selection-mode button.titlebutton {
  @include _button_text_shadow(white, $selected_bg_color);
  &:backdrop { -gtk-icon-shadow: none; }
}


// catch all extend :)

%selected_items {
  background-color: $selected_bg_color;
  color: $selected_fg_color;
  @if $variant == 'light' {
    outline-color: transparentize($selected_fg_color, 0.7);
  }
  &:insensitive { color: mix($selected_fg_color, $selected_bg_color, 50%); }
  &:backdrop {
    color: $backdrop_selected_fg_color;
    &:insensitive {
      color: mix($backdrop_selected_fg_color, $selected_bg_color, 30%);
    }
  }
}

.monospace {
  font: Monospace;
}

/**********************
 * Touch Copy & Paste *
 *********************/

//touch selection handlebars for the Popover.osd above
cursor-handle {
  background-color: transparent;
  background-image: none;
  box-shadow: none;
  border-style: none;
  @each $s,$as in ('',''),
                  (':hover','-hover'),
                  (':active','-active') { //no need for insensitive and backdrop
                    &.top#{$s}:dir(ltr), &.bottom#{$s}:dir(rtl) {
                      $_url: 'assets/text-select-start#{$as}#{$asset_suffix}';
                      -gtk-icon-source: -gtk-scaled(url('#{$_url}.png'),
                                        url('#{$_url}@2.png'));
                      padding-left: 10px;
                    }
                    &.bottom#{$s}:dir(ltr), &.top#{$s}:dir(rtl) {
                      $_url: 'assets/text-select-end#{$as}#{$asset_suffix}';
                      -gtk-icon-source: -gtk-scaled(url('#{$_url}.png'),
                                        url('#{$_url}@2.png'));
                      padding-right: 10px;
                    }
                    &.insertion-cursor#{$s}:dir(ltr), &.insertion-cursor#{$s}:dir(rtl) {
                      $_url: 'assets/slider-horz-scale-has-marks-above#{$as}#{$asset_suffix}';
                      -gtk-icon-source: -gtk-scaled(url('#{$_url}.png'),
                                        url('#{$_url}@2.png'));
     }
  }
}

/* Decouple the font of context menus from their entry/textview */
.context-menu {
  font: initial;
}

button.circular {
  border-radius: 20px;
  -gtk-outline-radius: 20px;
}

button.circular label {
  padding: 0;
}

frame.keycap {
  background-color: #fefefe;
  border: 1px solid #cecece;
  border-radius: 5px;
  box-shadow: 0px 1px 0px #fff inset,
              0px -2px 0px #dedede inset;
  color: #555753;
  padding: 3px 8px 3px 8px;
}

*:dnd:focus,
*:dnd {
  border: 1px solid black;
}

stackswitcher button.text-button {
  min-width: 100px;
}

stackswitcher button.circular {
  min-width: 0px;
}