//
// Suffix
//

$asset_suffix: if($variant == 'dark', '-dark', '');


//
// Background sizing
//

$text_button_large: rem(213px) * 1 / 0.8 rem(213px) * 1 / 0.8, auto;
$text_button_small: rem(106px) * 1 / 0.8 rem(106px) * 1 / 0.8, auto;
$image_button_large: rem(40px) * 1 / 0.8 rem(40px) * 1 / 0.8, auto;
$image_button_small: rem(26px) * 1 / 0.8 rem(26px) * 1 / 0.8, auto;
$attention: rem(5.3px) rem(5.3px);
$scale: 80%;
$separator_narrow: 1px 1px;
$separator_wide: 1px 1px, 1px 1px;


//
// transitions
//

%transition {
  // do not include sizing factors and text colors/shadows
  transition-property: opacity,
                       border-color,
                       border-image,
                       background-color,
                       background-image,
                       box-shadow,
                       icon-shadow;
  transition-timing-function: cubic-bezier(0.4, 0, 0.2, 1);
  transition-duration: 0.2s;
}


/*****************
 * Common States *
 *****************/

* {
  @extend %transition; // global transition setting

  padding: 0;
  background-clip: padding-box;

  -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;

  -GtkToolItemGroup-expander-size: 11;

  -GtkWidget-text-handle-width: 16;
  -GtkWidget-text-handle-height: 16;

  -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-style: solid;
  outline-width: 2px;
  outline-color: $track_color;
  outline-offset: rem(-4px);
  -gtk-outline-radius: 2px;

  -gtk-secondary-caret-color: $selected_bg_color;

  // disable drop-shadows as default
  text-shadow: none;
  -gtk-icon-shadow: none;
}


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

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

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

// for backdrop, tone down element surfaces with transparentize
%fade_effect {
  *:backdrop {
    opacity: 0.75;
    transition: 0.2s;
  }
}

.gtkstyle-fallback {
  background-color: $bg_color;
  color: $fg_color;
  &:hover {
    background-color: darken($bg_color, 5%);
    color: $fg_color;
  }
  &:active {
    background-color: darken($bg_color, 10%);
    color: $fg_color;
  }
  &:disabled {
    background-color: $bg_color;
    color: $insensitive_fg_color;
  }
  &:selected {
    background-color: $selected_bg_color;
    color: $selected_fg_color;
  }
}

.view,
%view {
  @extend row.activatable;
  background-color: $base_color;
  color: $fg_color;
  &:hover,
  &:active,
  &:selected {
    border-radius: 2px;
    -gtk-outline-radius: 2px;
  }
  &:disabled { color: $insensitive_fg_color; }
  &:backdrop {
  }
  &:selected,
  &:selected:focus { @extend %selected_items; }
}

.view,
textview {
  text {
    @extend %view;

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

textview border {
  background-color: $bg_color;
}

iconview { @extend .view; }

rubberband {
  border: 1px solid $secondary_selected_bg_color;
  background-color: gtkopacity($secondary_selected_bg_color, 0.2);
}

flowbox {
  rubberband { @extend rubberband; }

  flowboxchild {
    padding: rem(2px);
    border-radius: 2px;
    -gtk-outline-radius: 2px;
    &:selected {
      @extend %selected_items;
      outline-offset: rem(-2px);
    }
  }
}

label {
  caret-color: currentColor; // this shouldn't be needed.

  &.separator {
    @extend .dim-label;
    color: transparent;
  }

  &:selected,
  row:selected & { @extend %nobg_selected_items; }

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

  &:disabled {
    color: $insensitive_fg_color;

    selection { @extend %selected_items:disabled; }
  }

  // always use dark foreground in Gnome-Software
  &.kudo-label {
    color: $fixed_fg_color;
  }
}

.dim-label {
  opacity: 0.55;
}

assistant {
  // sidebar styling
  .sidebar {
    padding: rem(6.7px) 0;
    background-color: $secondary_dark_color;
    &:dir(ltr) { border-right: 1px solid $borders_color; }
    &:dir(rtl) { border-left: 1px solid $borders_color; }
  }

  &.csd .sidebar { border-top-style: none; }

  .sidebar label {
    padding: rem(5.3px) rem(8px) rem(6.7px);
    color: $secondary_fg_color;
    font-weight: 500;
    &.highlight { color: $selected_bg_color; }
  }

  // header-bar styling
  headerbar {
    // apply suggested-action button for "Next" and "Back"
    // last -> "cancel", nth -> "Next" and "Back", that's weird.
    button.flat:not(:last-child) {
      @include button(normal);
      background-color: $suggested_color;
      color: $secondary_selected_fg_color;
      &:hover {
        @include button(hover);
        color: $selected_fg_color;
      }
      &:active {
        @include button(active);
        color: $selected_fg_color;
        background-color: $selected_bg_color;
      }
      &:checked {
        @include button(checked);
        background-color: $suggested_color;
        color: $inverted_fg_color;
      }
      &:disabled { @include button(insensitive); }
    }
  }
}

// button box is always shown with flat-buttons
buttonbox {
  &, &.dialog-action-area {
    button {
      @include button(flat-normal);
      color: $secondary_accent_color;
      font-weight: 700;
      &:hover {
        @include button(flat-hover);
        color: $accent_color;
      }
      &:active {
        @include button(flat-active);
        color: $accent_color;
      }
      &:disabled { @include button(flat-insensitive); }
      &:checked {
        @include button(flat-checked);
        color: $accent_color;
      }
      &:checked:disabled {
        @include button(flat-checked-insensitive);
        color: gtkopacity($accent_color, 0.4);
      }
    }
  }
}

%osd, .osd { opacity: 0.9; }


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

@keyframes colorful_bar {
  0% {
    -gtk-icon-source: url("assets/bar-red.svg");
    -gtk-icon-transform: scale(0, 1.0);
  }
  24.9% {
    -gtk-icon-source: url("assets/bar-red.svg");
    -gtk-icon-transform: scale(1.0, 1.0);
  }
  25% {
    -gtk-icon-source: url("assets/bar-yellow.svg");
    -gtk-icon-transform: scale(1.0, 1.0);
  }
  49.9% {
    -gtk-icon-source: url("assets/bar-yellow.svg");
    -gtk-icon-transform: scale(0, 1.0);
  }
  50% {
    -gtk-icon-source: url("assets/bar-green.svg");
    -gtk-icon-transform: scale(0, 1.0);
  }
  74.9% {
    -gtk-icon-source: url("assets/bar-green.svg");
    -gtk-icon-transform: scale(1.0, 1.0);
  }
  75% {
    -gtk-icon-source: url("assets/bar-blue.svg");
    -gtk-icon-transform: scale(1.0, 1.0);
  }
  99.9% {
    -gtk-icon-source: url("assets/bar-blue.svg");
    -gtk-icon-transform: scale(0, 1.0);
  }
  100% {
    -gtk-icon-source: url("assets/bar-red.svg");
    -gtk-icon-transform: scale(0, 1.0);
  }
}

spinner {
  min-height: rem(16px);
  min-width: rem(16px);
  // FIXME: workaround for 3.20.1. Needs vertical padding more than 4px?
  padding: rem(5.3px) 0 rem(5.3px);
  margin: 0;
  background: none;
  opacity: 0; // non spinning spinner makes no sense
  -gtk-icon-source: url("assets/bar-red.svg");
  &:checked {
    opacity: 1.0;
    animation: colorful_bar 2s linear infinite;
    &:disabled { opacity: 0.4; }
    &:backdrop { opacity: 1.0; }
  }
  &:backdrop { opacity: 0; }
}


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

entry {
  min-height: rem(13.3px);
  min-width: rem(33.3px);
  padding: rem(9.3px) rem(8px) rem(10.7px);
  @include entry(normal);

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

  &.flat {
    border-radius: 0;
    @include entry(flat-normal);
    &:focus { @include entry(flat-focus); }
    &:disabled { @include entry(flat-insensitive); }
  }

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

  image { // icons inside the entry
    padding-left: rem(4px);
    padding-right: rem(4px);
  }

  progress { @extend %entry_progressbar; }

  .linked > &:not(.flat),
  .linked.vertical > &:not(.flat) {
    @extend entry.flat;
    border-radius: 0;
    -gtk-outline-radius: 0;
  }

  // entry error, warning and missing style
  @each $e_type, $e_color in (error, $error_color),
                             (warning, $warning_color),
                             (search-missing, $error_color) {
    &.#{$e_type} {
      @include entry(normal, $e_color);
      &:focus { @include entry(focus, $e_color); }
      &:disabled { @include entry(insensitive, $e_color); }
      &.flat {
        @include entry(flat-normal, $e_color);
        &:focus { @include entry(flat-focus, $e_color); }
        &:disabled { @include entry(flat-insensitive, $e_color); }
      }
    }
  }

  & image { // entry icons colors
    &:not(:hover):not(:active) { color: gtkalpha(currentColor, 0.75); }
    &:active { color: $selected_bg_color; }
    &:disabled { color: gtkalpha(currentColor, 0.55); }
  }

  &:drop(active) {
    &, &:focus {
      border-color: $drop_target_color;
      box-shadow: inset 0 0 0 1px $drop_target_color;
    }
  }

  treeview & { // reset styling inside tree-view
    &, &.flat:focus {
      padding: 1px;
      border-radius: 0;
      border-image: none;
      background-color: $base_color;
      color: $fg_color;
      box-shadow: none;
      transition-property: color,
                           background;

      &:selected { @extend %selected_items; }
    }
  }

  .osd & {
  }
}


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

// stuff for .needs-attention
@keyframes needs_attention {
  from {
    background-image: -gtk-gradient(radial,
                                    center center, 0,
                                    center center, 0.001,
                                    to($selected_bg_color),
                                    to(transparent));
  }
  to {
    background-image: -gtk-gradient(radial,
                                    center center, 0,
                                    center center, 0.5,
                                    to($selected_bg_color),
                                    to(transparent));
  }
}

button {
  min-height: rem(13.3px);
  min-width: rem(33.3px);
  padding: rem(9.3px) rem(13.3px) rem(10.7px);
  border-radius: 2px;
  -gtk-outline-radius: 2px;
  background-repeat: no-repeat;
  background-position: center, center;
  background-size: $text_button_small;
  font-weight: 500;
  @include button(normal);
  &:hover { @include button(hover); }
  &:active { @include button(active); }
  &:disabled { @include button(insensitive); }
  &:checked { @include button(checked); }
  &:checked:disabled { @include button(checked-insensitive); }
  &.flat {
    @include button(flat-normal);
    &:hover { @include button(flat-hover); }
    &:active { @include button(flat-active); }
    &:disabled { @include button(flat-insensitive); }
    &:checked { @include button(flat-checked); }
    &:checked:disabled { @include button(flat-checked-insensitive); }
    .linked > & {
      border-radius: 2px;
      -gtk-outline-radius: 2px;
      &.image-button {
        border-radius: 100px;
        -gtk-outline-radius: 100px;
      }
    }
  }

  // big standalone buttons like in Documents pager
  &.osd {
    &.image-button {
      @extend button.flat;
      @extend %image_button;
      padding: rem(17.3px);
      background-color: $inverted_dark_color;
      background-size: $image_button_large;
      &:not(:active):not(:disabled):not(hover) {
        color: $secondary_accent_color;
      }
      &:hover {
        color: $accent_color;
        background-color: gtkopacity($inverted_dark_color, 0.7);
        background-image: linear-gradient(to bottom, $track_color, $track_color);
      }
      &:active {
        color: $accent_color;
        background-color: gtkopacity($inverted_dark_color, 0.7);
        background-image: linear-gradient(to bottom, $accent_fill_color, $accent_fill_color);
      }
    }
    &:disabled { opacity: 0; }
  }

  // overlay / OSD style
  .osd & {
  }

  // Suggested and Destructive Action buttons
  @each $b_type, $b_color in (suggested-action, $suggested_color),
                             (destructive-action, $destructive_color) {
    &.#{$b_type} {
      background-color: $b_color;
      background-size: $text_button_small;
      color: $selected_fg_color;
      &:hover {
        @include button(hover);
        background-color: $b_color;
        color: $selected_fg_color;
      }
      &:active {
        @include button(active);
        background-color: $selected_bg_color;
        color: $selected_fg_color;
      }
      &:checked { background-color: mix($selected_fg_color, $b_color, 20%); }
      &:disabled {
        @include button(insensitive, $b_color,
                                     $insensitive_selected_fg_color);
      }
      &.flat {
        background-color: transparent;
        color: $b_color;
        &:hover { @include button(flat-hover, $track_color, $b_color); }
        &:active {
          @include button(flat-active);
          background-color: gtkalpha($selected_bg_color, 0.2);
          color: $selected_bg_color;
        }
        &:checked { @include button(flat-checked, $b_color, $selected_fg_color); }
        &:disabled {
          @include button(flat-insensitive, $b_color,
                                            $insensitive_selected_fg_color);
        }
      }
    }
  }

  &.image-button {
    @extend %image_button;
    min-width: rem(13.3px);
    min-height: rem(13.3px);
  }

  &.text-button {
    padding: rem(9.3px) rem(13.3px) rem(10.7px);
    border-radius: 2px;
    -gtk-outline-radius: 2px;
    font-weight: 700;
  }

  &.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-left: rem(13.3px);
    padding-right: rem(13.3px);
    border-radius: 2px;
    -gtk-outline-radius: 2px;

    label {
      padding-left: rem(4px);
      padding-right: rem(4px);
    }

    image {
      padding-left: rem(4px);
      padding-right: rem(4px);
    }

    &:drop(active) {
      color: $drop_target_color;
      background-color: $drop_target_fill_color;
    }
  }

  separator { // remove vertical separator
    @extend separator.wide;
    min-height: 0;
    min-width: 0;
    border-color: transparent;
    background-color: transparent;
    color: transparent;
  }

  stackswitcher & { // do not shrink buton width
    &.text-button {
      min-height: rem(17.3px);
      min-width: rem(112px);
    }
  }

  .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: rem(-2.6px); // needs to be set or it gets overriden
                                 // by GtkRadioButton outline-offset

    > label {
      padding-left: rem(8px);  // label padding
      padding-right: rem(8px); //
    }

    > image {
      padding-left: rem(8px);     // image padding
      padding-right: rem(8px);    //
      padding-top: rem(2.7px);    //
      padding-bottom: rem(2.7px); //
    }

    &.text-button {
      // compensate text-button paddings
      padding-left: rem(13.3px);
      padding-right: rem(13.3px);
      border-radius: 2px;
      -gtk-outline-radius: 2px;
    }

    &.image-button {
      // we want image buttons to have a 1:1 aspect ratio, so compensation
      // of the padding added to the image is needed
      padding-left: rem(8px);
      padding-right: rem(8px);
    }

    &.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;
    }
  }

  // mimic tab-switcher-like button array
  // horizontal array
  .linked > &:not(.flat):not(:only-child) { @extend %linked_middle; }
  .linked > &,
  .linked > & .image-button,
  .linked > & .text-button {
    @extend %linked_middle;
    @extend %button_array;
    min-width: rem(13.3px);
    padding: rem(9.3px) rem(5.3px) rem(10.7px);

    label {
      padding-left: rem(4px);
      padding-right: rem(4px);
    }

    image {
      padding-left: rem(4px);
      padding-right: rem(4px);
    }
  }
  // vertical array
  .linked.vertical > &:not(:only-child) { @extend %linked_vertical_middle; }
  .linked.vertical > &,
  .linked.vertical > & .image-button,
  .linked.vertical > & .text-button {
    @extend %linked_vertical_middle;
    @extend %button_vertical_array;
    min-height: rem(13.3px);
    min-width: rem(22.6px);
    padding: rem(10px) rem(6.7px) rem(10px);
  }

  // generic switcher image buttons
  .linked > &.image-button.radio,
  .linked.vertical > &.image-button.radio {
      min-width: rem(13.3px);
      min-height: rem(13.3px);
      padding: rem(8px);
  }

  // inline-toolbar and action-bar buttons
  .inline-toolbar &,
  actionbar {
    &, &:not(.text-button).image-button {
      @include button(flat-normal);
      min-width: rem(13.3px);
      min-height: rem(13.3px);
      padding: rem(10px);
      border-radius: 100px;
      -gtk-outline-radius: 100px;
      background-size: $image_button_small;
      &:hover { @include button(flat-hover); }
      &:active { @include button(flat-active); }
      &:disabled { @include button(flat-insensitive); }
      &:checked { @include button(flat-checked); }
      &:checked:disabled { @include button(flat-checked-insensitive); }
    }
    &.text-button {
      border-radius: 2px;
      -gtk-outline-radius: 2px;
    }
  }
  .inline-toolbar .linked > &,
  actionbar .linked > & {
    &, &:not(.text-button).image-button {
      min-width: rem(13.3px);
      min-height: rem(13.3px);
      padding: rem(6.7px);
      border-radius: 100px;
      -gtk-outline-radius: 100px;
    }
    &.image-button.toggle {
      min-width: rem(13.3px);
      min-height: rem(13.3px);
      padding: rem(8px) rem(4px) rem(8px);
      border-radius: 100px;
      -gtk-outline-radius: 100px;
    }
    &.text-button {
      border-radius: 2px;
      -gtk-outline-radius: 2px;
    }
  }

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

%button_array {
  @include button(flat-normal);
  border-radius: 0;
  -gtk-outline-radius: 0;
  color: $secondary_fg_color;
  border-image: -gtk-gradient(radial,
                              center bottom, 0,
                              center bottom, 0.5,
                              to($track_color),
                              to(transparent))
                              0 0 1 / 0 0 1px;
  &:hover {
    @include button(flat-hover);
    border-radius: 0;
    border-image: -gtk-gradient(radial,
                                center bottom, 0,
                                center bottom, 0.5,
                                to($track_color),
                                to(transparent))
                                0 0 2 / 0 0 2px;
  }
  &:active,
  &:checked {
    color: $fg_color;
    background-color: transparent;
    border-image: -gtk-gradient(radial,
                                center bottom, 0,
                                center bottom, 0.5,
                                to($selected_bg_color),
                                to(transparent))
                                0 0 2 / 0 0 2px;
    &:disabled {
      color: $insensitive_fg_color;
      background-color: transparent;
      border-image: -gtk-gradient(radial,
                                  center bottom, 0,
                                  center bottom, 0.5,
                                  to(gtkopacity($selected_bg_color, 0.2)),
                                  to(transparent))
                                  0 0 2 / 0 0 2px;
      > label { color: inherit; }
    }
  }
  &:disabled {
    color: $insensitive_fg_color;
    background-color: transparent;
    border-image: -gtk-gradient(radial,
                                center bottom, 0,
                                center bottom, 0.5,
                                to($track_color),
                                to(transparent))
                                0 0 1 / 0 0 1px;
  }
}

%button_vertical_array {
  @include button(flat-normal);
  border-image: none;
  border-width: 0;
  -gtk-outline-radius: 0;
  color: $secondary_fg_color;
  &:dir(ltr) { box-shadow: inset 1px 0 $track_color; }
  &:dir(rtl) { box-shadow: inset -1px 0 $track_color; }
  &:hover {
    @include button(flat-hover);
    &:dir(ltr) { box-shadow: inset 2px 0 $track_color; }
    &:dir(rtl) { box-shadow: inset -2px 0 $track_color; }
  }
  &:active,
  &:checked {
    color: $fg_color;
    background-color: transparent;
    &:dir(ltr) { box-shadow: inset 2px 0 $selected_bg_color; }
    &:dir(rtl) { box-shadow: inset -2px 0 $selected_bg_color; }
    &:disabled {
      color: $insensitive_fg_color;
      background-color: $track_color;
      &:dir(ltr) { box-shadow: inset 2px 0 gtkopacity($selected_bg_color, 0.2); }
      &:dir(ltr) { box-shadow: inset -2px 0 gtkopacity($selected_bg_color, 0.2); }
      > label { color: inherit; }
    }
  }
  &:disabled {
    color: $insensitive_fg_color;
    background-color: $track_color;
    &:dir(ltr) { box-shadow: inset 1px 0 $track_color; }
    &:dir(rtl) { box-shadow: inset -1px 0 $track_color; }
  }
}

%image_button {
  padding: rem(10px);
  border-radius: 100px;
  -gtk-outline-radius: 100px;
  background-size: $image_button_large;
}

%needs_attention {
  transition: none;
  animation: needs_attention 0.2s cubic-bezier(0.4, 0, 0.2, 1) forwards;
  background-repeat: no-repeat;
  background-position: right rem(3px);
  background-size: $attention;
  &:dir(rtl) { background-position: left rem(3px); }
}

// all the following is for the +|- buttons on inline toolbars, that way
// should really be deprecated...
toolbar.inline-toolbar toolbutton > button { // redefining the button look is
                                             // needed since those are flat...
}

// More inline toolbar buttons
toolbar.inline-toolbar toolbutton {
  // & > 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; }
}

%linked_middle { border-radius: 0; }

%linked {
  -gtk-outline-radius: 2px;
  @extend %linked_middle;
  &:first-child {
    border-top-left-radius: 2px;
    border-bottom-left-radius: 2px;
  }
  &:last-child {
    border-top-right-radius: 2px;
    border-bottom-right-radius: 2px;
  }
  &:only-child { border-radius: 2px; }
}

%linked_vertical_middle { border-radius: 0; }

%linked_vertical{
  -gtk-outline-radius: 2px;
  @extend %linked_vertical_middle;
  &:first-child {
    border-top-left-radius: 2px;
    border-top-right-radius: 2px;
  }
  &:last-child {
    border-bottom-left-radius: 2px;
    border-bottom-right-radius: 2px;
  }
  &:only-child { border-radius: 2px; }
}

// menu buttons on GtkPopover
modelbutton.flat,
menuitem button.flat {
  @include button(flat-normal);
  min-height: rem(26.6px);
  margin-left: rem(10px);
  margin-right: rem(10px);
  outline-offset: rem(-1px);
  background-size: $text_button_small;
  transition: none;
  &:hover { @include button(flat-hover); }
  &:active { @include button(flat-active); }
  &:disabled { @include button(flat-insensitive); }
  &:checked { @include button(flat-checked); }
  &:checked:disabled { @include button(flat-checked-insensitive); }

  check,
  radio {
    &:first-child { margin-right: rem(13.3px); }
    &:last-child { margin-left: rem(13.3px); }
  }
}

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 {
  min-width: rem(33.3px);
  min-height: rem(20px);
  padding: rem(6.7px) rem(8px) rem(6.7px); // Uniform padding on the GtkColorButton

  > colorswatch:first-child:last-child { // :first-child:last-child for
                                         // a specificity bump, it gets
                                         // overridden by the colorpicker style
    &, overlay {
      border-radius: 2px;
      -gtk-outline-radius: 2px;
    }
    box-shadow: $z-depth-1;
  }

  &,
  GtkColorSwatch {
    &:disabled {
      box-shadow: none;
      opacity: 0.4;
    }
  }
}

// toolpalette buttons
toolpalette {
  toolitemgroup {
    > button {
      border-top: 1px solid $borders_color;
      border-radius: 0;
    }
  }

  toolbutton {
    > button.toggle { // use square buttons
      border-radius: 2px;
      -gtk-outline-radius: 2px;
    }
  }
}


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

*:link {
  color: $link_color;
  &:hover,
  &:active { color: $link_color; }
  &:visited {
    color: $link_visited_color;
    &:hover,
    &:active { color: $link_visited_color; }
    *:selected & { color: mix($selected_fg_color, $selected_bg_color, 60%); }
  }
  &:selected,
  *:selected & { color: mix($selected_fg_color, $selected_bg_color, 80%); }
  &:disabled { opacity: 0.4; }
}

button:link,
button:visited {
  // FIXME: aggregate with buttons
  @extend *:link;
  & > label { text-decoration-line: underline; }
}


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

@keyframes spin_hover {
  from {
    background-image: -gtk-gradient(radial,
                                    center center, 0,
                                    center center, 0.01,
                                    to(gtkalpha(currentColor, 0)),
                                    to(transparent));
  }
  to {
    background-image: -gtk-gradient(radial,
                                    center center, 0,
                                    center center, 0.5,
                                    to(gtkalpha(currentColor, 0.1)),
                                    to(transparent));
  }
}

@keyframes spin_active {
  from {
    background-image: -gtk-gradient(radial,
                                    center center, 0,
                                    center center, 0.5,
                                    to(gtkalpha(currentColor, 0.2)),
                                    to(transparent));
  }
  to {
    background-image: -gtk-gradient(radial,
                                    center center, 0,
                                    center center, 0.01,
                                    to(gtkalpha(currentColor, 0)),
                                    to(transparent));
  }
}

spinbutton {
  &:not(.vertical) {
    // in this horizontal configuration, the whole spinbutton
    // behaves as the entry, so we extend the entry styling
    // and nuke the style on the internal entry
    @extend entry;
    padding: 0;

    // FIXME: this should not be set at all, but otherwise it gets the wrong
    // color
    &:disabled { color: $insensitive_fg_color; }

    entry {
      margin: 0;
      background: none;
      border: none;
      box-shadow: none;
    }

    button {
      @include button(flat-normal);
      min-width: rem(13.3px);
      min-height: rem(13.3px);
      padding: 0 rem(7.3px) 0;
      border: solid rem(2.7px) transparent;
      border-radius: 100px;
      -gtk-outline-radius: 100px;
      background: none;
      background-size: contain;
      color: $secondary_fg_color;
      box-shadow: none;
      transition-property: opacity,
                           color,
                           background-color,
                           background-image,
                           box-shadow;

      &:not(:last-child) { // '-' button
        &:hover {
          @include button(flat-hover);
          background: none;
          color: $error_color;
          animation: spin_hover 0.2s cubic-bezier(0.4, 0, 0.2, 1) forwards;
        }
        &:active {
          @include button(flat-active);
          background: none;
          color: $error_color;
          animation: spin_active 0.15s cubic-bezier(0.4, 0, 0.2, 1) forwards;
          transition-duration: 0.15s;
        }
        &:disabled {
          @include button(flat-insensitive);
          background: none;
          color: $insensitive_fg_color;
        }
      }
      &:last-child { // '+' button
        &:hover {
          @include button(flat-hover);
          background: none;
          color: $success_color;
          animation: spin_hover 0.2s cubic-bezier(0.4, 0, 0.2, 1) forwards;
        }
        &:active {
          @include button(flat-active);
          background: none;
          color: $success_color;
          animation: spin_active 0.15s cubic-bezier(0.4, 0, 0.2, 1) forwards;
          transition-duration: 0.15s;
        }
        &:disabled {
          @include button(flat-insensitive);
          background: none;
          color: $insensitive_fg_color;
        }
      }
    }
  }

  .osd &,
  .osd &.vertical {
    &,
    button,
    entry {
      color: $inverted_secondary_fg_color;
      &:focus { color: $inverted_fg_color; }
      &:disabled { color: $insensitive_inverted_secondary_fg_color; }
    }
  }

  &.vertical { // FIXME: try using linking templates for
               // vertically linked stuff
    entry {
      min-width: rem(33.3px);
      min-height: rem(33.3px);
      padding: 0;
      border-radius: 0;
    }

    button {
      min-width: rem(26.7px);
      min-height: rem(26.7px);
      padding: rem(2.7px);
      border: rem(2.7px) solid transparent;
      border-radius: 200px;
      -gtk-outline-radius: 200px;
      background: none;
      background-size: contain;
      color: $secondary_fg_color;
      box-shadow: none;
      transition-property: opacity,
                           color,
                           background-color,
                           background-image,
                           box-shadow;

      &.up { // '+' button
        &:hover {
          @include button(flat-hover);
          background: none;
          color: $success_color;
          animation: spin_hover 0.2s cubic-bezier(0.4, 0, 0.2, 1) forwards;
        }
        &:active {
          @include button(flat-active);
          background: none;
          color: $success_color;
          animation: spin_active 0.15s cubic-bezier(0.4, 0, 0.2, 1) forwards;
          transition-duration: 0.15s;
        }
        &:disabled {
          @include button(flat-insensitive);
          background: none;
          color: $insensitive_fg_color;
        }
      }
      &.down { // '-' button
        &:hover {
          @include button(flat-hover);
          background: none;
          color: $error_color;
          animation: spin_hover 0.2s cubic-bezier(0.4, 0, 0.2, 1) forwards;
        }
        &:active {
          @include button(flat-active);
          background: none;
          color: $error_color;
          animation: spin_active 0.15s cubic-bezier(0.4, 0, 0.2, 1) forwards;
          transition-duration: 0.15s;
        }
        &:disabled {
          @include button(flat-insensitive);
          background: none;
          color: $insensitive_fg_color;
        }
      }
    }
  }

  // Misc
  treeview & {
    & entry:focus {
      padding: 1px;
      border-radius: 0;
      border-width: 0;
      background-color: $base_color;
      color: $fg_color;
      box-shadow: none;
      &:selected { @extend %selected_items; }
    }
  }
}


/**************
 * ComboBoxes *
 **************/

combobox {
  arrow {
    -gtk-icon-source: -gtk-icontheme('pan-down-symbolic');
    min-height: rem(16px);
    min-width: rem(16px);
  }

  &.linked {
    button:nth-child(2) {
      &:dir(ltr) { @extend %linked:last-child; }
      &:dir(rtl) { @extend %linked:first-child; }
    }
  }

  &:drop(active) {
    button.combo { @extend button:drop(active); }
  }

  & menu { padding: rem(3.3px) 0; }
  & menu > menuitem { padding: rem(4.7px) rem(5.3px) rem(6px); }

  entry.combo {
  }

  button.combo { // button spacing
    min-height: rem(13.3px);
    min-width: rem(17.3px);
    padding: rem(8px) rem(5.3px) rem(8.7px);

    arrow { padding: 0 rem(4px) 0; }

    label {
      padding-left: rem(4px);
      padding-right: rem(4px);
    }

    image {
      min-height: rem(16px);
      min-width: rem(16px);
      padding-left: rem(4px);
      padding-right: rem(4px);
    }
  }

  button.combo { // button styling
    @include button(flat-normal);
    color: $secondary_fg_color;
    background: transparent;
    border-image: -gtk-gradient(radial,
                                center bottom, 0,
                                center bottom, 0.5,
                                to($track_color),
                                to(transparent))
                                0 0 1 / 0 0 1px;
    &:hover,
    &:active {
      @include button(flat-hover);
      border-radius: 0;
      color: $fg_color;
      background: transparent;
      border-image: -gtk-gradient(radial,
                                  center bottom, 0,
                                  center bottom, 0.5,
                                  to($selected_bg_color),
                                  to(transparent))
                                  0 0 2 / 0 0 2px;
    }
    &:disabled,
    &:checked:disabled {
      @include button(flat-insensitive);
      color: $insensitive_fg_color;
      background: transparent;
      border-image: -gtk-gradient(radial,
                                  center bottom, 0,
                                  center bottom, 0.5,
                                  to($track_color),
                                  to(transparent))
                                  0 0 1 / 0 0 1px;

    }
  }

  button.combo:not(:only-child) {
  }
  button.combo:only-child {
  }
}

.linked > combobox > box > button.combo {
  // the combo is a composite widget so the way we do button linking 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: rem(5.3px);
  background-color: $bg_color;
  color: $secondary_fg_color;
  box-shadow: if($variant == 'light', $toolbar-shadow-light,
                                      $toolbar-shadow-dark);

  &.vertical,
  .inline-toolbar &,
  paned &,
  paned &.primary-toolbar,
  grid &.primary-toolbar { // stop drawing fake-shadows
    box-shadow: none;
  }

  // on OSD
  .osd & { background-color: transparent; }

  .osd &,
  &.osd {
    padding: 3px;
    border-style: solid;
    border-width: 9px;
    border-radius: 2px;
    border-image: -gtk-scaled(url("assets/osd-shadow#{$asset_suffix}.png"),
                              url("assets/osd-shadow#{$asset_suffix}@2.png"))
                  10 / 10px stretch;
    box-shadow: none;
    color: $inverted_fg_color;
    background-color: $inverted_dark_color;
    &:backdrop {
      border-image: -gtk-scaled(url("assets/osd-shadow-backdrop#{$asset_suffix}.png"),
                                url("assets/osd-shadow-backdrop#{$asset_suffix}@2.png"))
                    10 / 10px stretch;
    }

    button {
      @extend button.flat;
      &:not(:active):not(:disabled):not(hover) {
        color: $secondary_accent_color;
      }
      &:hover,
      &:active { color: $accent_color; }
      &:active,
      &:checked {
        border-image: none;
        box-shadow: none;
      }
      &:disabled { color: gtkopacity($accent_color, 0.4); }
    }

    .linked > button {
      &, &.image-button {
        border-image: none;
        box-shadow: none;
        &:hover { background-color: transparent; }
        &:not(:checked) {
          border-radius: 100px;
          -gtk-outline-radius: 100px;
        }
      }

      &.image-button {
        min-width: rem(13.3px);
        min-height: rem(29.3px);
        padding: 0 rem(6.7px) 0;
        border-radius: 100px;
        -gtk-outline-radius: 100px;
      }
    }

    label { padding: 0 1em; }
  }

  button { // use flat-buttons
    @extend button.flat;
    background-size: $text_button_small;
    box-shadow: none;
    border-image: -gtk-gradient(radial,
                                center bottom, 0,
                                center bottom, 0.001,
                                to($track_color),
                                to(transparent))
                                0 0 0 / 0 0 0px;
    color: $secondary_fg_color;
    &:hover {
      box-shadow: none;
      border-image: none;
      color: $fg_color;
    }
    &:checked {
      box-shadow: none;
      border-image: -gtk-gradient(radial,
                                  center bottom, 0,
                                  center bottom, 0.5,
                                  to($selected_bg_color),
                                  to(transparent))
                                  0 0 2 / 0 0 2px;
      background-color: transparent;
      color: $fg_color;
      &:disabled {
        box-shadow: none;
        background-color: transparent;
        color: $insensitive_fg_color;
        border-image: none;
        > label { color: inherit; }
      }
    }
    &:disabled {
      box-shadow: none;
      background-color: transparent;
      color: $insensitive_secondary_fg_color;
      border-image: none;
    }

    button,
    button.flat { // set specific roundness
      &,
      &.text-button,
      &.text-button.image-button {
        border-radius: 2px;
	-gtk-outline-radius: 2px;
      }
      &.image-button {
        border-radius: 100px;
	-gtk-outline-radius: 100px;
      }
    }

    .text-button,
    .image-button.text-button {
      min-width: rem(13.3px);
      min-height: rem(29.3px);
      padding: 0 rem(13.3px) 0;
      background-size: $text_button_small;
    }

    .image-button {
      min-width: rem(13.3px);
      min-height: rem(29.3px);
      padding: 0 rem(6.7px) 0;
      background-size: $image_button_large;
    }

    &.toggle { // remove double-background
      &:hover,
      &:active,
      &:checked {
        background-color: transparent;
        box-shadow: none;
      }
    }
  }

  .linked > button { // remove double-background and underlines
    &, &.image-button {
      border-image: none;
      box-shadow: none;
      &:hover,
      &:active {
        border-image: none;
        background-color: transparent;
        box-shadow: none;
      }
      &:not(:disabled) { // revive roundness
        border-radius: 100px;
        -gtk-outline-radius: 100px;
      }
    }

    .image-button {
      min-width: rem(13.3px);
      min-height: rem(29.3px);
      padding: 0 rem(6.7px) 0;
      border-radius: 100px;
      -gtk-outline-radius: 100px;
    }
  }
  .linked > button.text-button:not(.image-button) { // revive underlines
    @extend %button_array;
  }

  // toolbar separators
  separator {
    color: transparent;
    background: none;
  }
  &.horizontal {
    separator { margin: 0 rem(6px); }
  }
  &.vertical {
    separator { margin: rem(6px) 0; }
  }
}

// searchbar, location-bar & inline-toolbar
.inline-toolbar {
  padding: rem(5.3px);
  border-style: solid;
  border-width: 0 1px 1px;
  border-color: $borders_color;
  background-color: $secondary_dark_color;
  box-shadow: if($variant == 'light', $inline-shadow-light,
                                      $inline-shadow-dark);
}

searchbar,
.location-bar {
  padding: rem(5.3px);
  border-style: solid;
  border-width: 0 0 1px;
  border-color: $borders_color;
  background-color: $secondary_dark_color;

  .linked > button.image-button {
    padding-top: rem(9.3px);
    padding-bottom: rem(10.7px);
  }

  button.flat.close.raised {
    min-width: rem(13.3px);
    min-height: rem(13.3px);
    padding: rem(10px);
    border-radius: 100px;
    -gtk-outline-radius: 100px;
  }
}


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

.titlebar,
headerbar {
  @extend %fade_effect;
  background-color: $inverted_dark_color;
  background-clip: border-box;

  // text colours
  color: $inverted_secondary_fg_color;
  label,
  image {
    // &:hover { color: $inverted_fg_color; }
    // &:focus,
    // &:active,
    &:checked {
    // color: $inverted_fg_color;
      &:disabled { color: $insensitive_inverted_fg_color; }
    }
    button:disabled > &,
    .linked > button:disabled > &,
    &:disabled { color: $insensitive_inverted_secondary_fg_color; }
  }

  // titles
  .title {
    padding-left: rem(13.3px);
    padding-right: rem(13.3px);
    color: $inverted_fg_color;
    font-weight: 700;
    &:backdrop { @extend .dim-label; }
  }

  .subtitle {
    @extend .dim-label;
    padding-left: rem(13.3px);
    padding-right: rem(13.3px);
    color: $inverted_secondary_fg_color;
    font-size: 90%;
    &:backdrop { @extend .dim-label; }
  }

  // separators
  & separator.vertical,
  & > box > separator.vertical,
  & > box > box > separator.vertical {
    border: 0 none transparent;
    color: transparent;
    background-color: transparent;
  }

  // button styling
  button:not(.suggested-action):not(.destructive-action) {
    @extend button.flat;
    border-image: -gtk-gradient(radial,
                                center bottom, 0,
                                center bottom, 0.001,
                                to($selected_bg_color),
                                to(transparent))
                                0 0 0 / 0 0 0px;
    color: $inverted_secondary_fg_color;
    background-size: $text_button_small;
    &:hover { color: $inverted_fg_color; }
    &:checked {
      border-image: -gtk-gradient(radial,
                                  center bottom, 0,
                                  center bottom, 0.5,
                                  to($selected_bg_color),
                                  to(transparent))
                                  0 0 2 / 0 0 2px;
      // box-shadow: inset 0 -2px $selected_bg_color;
      background-color: transparent;
      color: $inverted_fg_color;
      // transition: all 0.2s cubic-bezier(0.4, 0, 0.2, 1),
      //             box-shadow 0 cubic-bezier(0.4, 0, 0.2, 1) 0.2s,
      //             color 0;
      // &:active { transition: none; }
      &:disabled {
        background-color: transparent;
        color: $insensitive_inverted_fg_color;
        > label { color: inherit; }
      }
    }
  }

  // force to draw circle flat buttons as default
  button:not(.suggested-action):not(.destructive-action) {
    border-radius: 100px;
    -gtk-outline-radius: 100px;
    &.text-button {
      border-radius: 2px;
      -gtk-outline-radius: 2px;
      &.image-button {
        border-radius: 2px;
        -gtk-outline-radius: 2px;
        background-size: $text_button_small;
      }
    }
  }

  // adjust spacing for finer aspect-ratio
  .linked > button {
    &.image-button {
      min-width: rem(17.3px);
      min-height: rem(37.3px);
      padding: 0 rem(6.7px) 0;
    }
  }
  button.toggle {
    min-width: rem(17.3px);
    min-height: rem(37.3px);
    padding: 0 rem(10px) 0;

    label { padding: rem(9.3px) rem(8px) rem(10.7px); }
    menu menuitem { // reset padding
      label { padding: 0; }
    }
  }

  button,
  .linked > button,
  button.suggested-action,
  button.destructive-action {
    &, & label.text-button {
      color: $inverted_secondary_fg_color;
      &:hover { color: $inverted_fg_color; }
      &:checked {
        color: $inverted_fg_color;
        &:disabled { color: $insensitive_inverted_fg_color; }
      }
      &:disabled { color: $insensitive_inverted_secondary_fg_color; }
    }
    label.text-button { // workaround for Gnome-Software
      border-image: none;
      box-shadow: none;
    }
  }

  // entry styling
  entry,
  .linked > entry {
    color: $inverted_secondary_fg_color;
    caret-color: $inverted_secondary_fg_color;
    &:focus {
      color: $inverted_fg_color;
      caret-color: $inverted_fg_color;
    }
    &:disabled { color: $insensitive_inverted_secondary_fg_color; }
  }

  // combobox styling
  combobox,
  .linked > combobox {
    & > entry.combo {
      color: $inverted_secondary_fg_color;
      caret-color: $inverted_secondary_fg_color;
      &:focus {
        color: $inverted_fg_color;
        caret-color: $inverted_fg_color;
      }
      &:disabled { color: $insensitive_inverted_secondary_fg_color; }
      &:backdrop { opacity: 0.5; }
    }
    & > button.combo {
      color: $inverted_secondary_fg_color;
      &:hover { color: $inverted_fg_color; }
      &:checked {
        color: $inverted_fg_color;
        &:disabled { color: $insensitive_inverted_fg_color; }
      }
      &:disabled { color: $insensitive_inverted_secondary_fg_color; }
      &:backdrop { opacity: 0.5; }
    }
  }

  // menu styling
  menu menuitem { // reset text colour
    color: $secondary_fg_color;
    &:hover { color: $fg_color; }
    label {
      &:disabled { color: $insensitive_fg_color; }
    }
    & accelerator { color: gtkalpha(currentColor, 0.55); }
    & separator { color: $borders_color; }
  }

  // pop-over styling
  popover button.flat {
    color: $secondary_fg_color;
    &:hover { color: $fg_color; }
    label {
      &:hover { color: $fg_color; }
      &:disabled { color: $insensitive_fg_color; }
    }
  }

  // switch styling
  switch {
    margin: rem(2.7px) 0;
    color: $inverted_secondary_fg_color;
    background-color: gtkopacity($inverted_secondary_fg_color, 0.1);
    &:checked {
      background-color: gtkopacity($selected_bg_color, 0.2);
      &:disabled { background-color: gtkopacity($selected_bg_color, 0.2); }
    }
    &:disabled {
      color: $insensitive_inverted_fg_color;
      background-color: $track_color;
    }

    slider { background-color: $inverted_bg_color; }
    &:hover slider {
      background-image: linear-gradient(to bottom,
                                        gtkalpha($selected_fg_color, 0.2),
                                        gtkalpha($selected_fg_color, 0.2));
    }
    &:checked slider {
      background-color: $selected_bg_color;
      &:disabled { background-color: #3F4E56; }
    }
    &:disabled slider { background-color: #3F4E56; }
  }

  // spinner spacing
  spinner {
    min-width: rem(13.3px);
    min-height: rem(13.3px);
    margin: rem(-5.3px);
  }

  // selection-mode styling
  &.selection-mode {
    border-width: 1px 0 1px 0; // remove side borders
    border-top-color: $highlight_color;
    border-bottom-color: transparent;
    background-color: $selected_bg_color;
    color: $selected_fg_color;

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

    button,
    button.image-button {
      border-image: -gtk-gradient(radial,
                                  center bottom, 0,
                                  center bottom, 0.001,
                                  to($selected_fg_color),
                                  to(transparent))
                                  0 0 0 / 0 0 0px;
      color: $secondary_selected_fg_color;
      &:hover,
      &:active,
      &:checked { color: $selected_fg_color; }
      &:disabled { color: $insensitive_inverted_secondary_fg_color; }
      &:checked {
        border-image: -gtk-gradient(radial,
                                    center bottom, 0,
                                    center bottom, 0.5,
                                    to($selected_fg_color),
                                    to(transparent))
                                    0 0 2 / 0 0 2px;
        color: $selected_fg_color;
        background-color: transparent;
        &:disabled {
          color: $insensitive_selected_fg_color;
          > label { color: inherit; }
        }
      }
      &.suggested-action {
        // NOTE: do not use @extend button;
        @include button(normal);
        &:hover { @include button(hover); }
        &:active { @include button(active); }
        &:disabled { @include button(insensitive); }
      }

      // text-button foreground colors
      &.text-button,
      &.suggested-action {
        color: $secondary_selected_fg_color;
        &:hover,
        &:active,
        &:checked { color: $selected_fg_color; }
        &:disabled { color: $insensitive_selected_fg_color; }
      }
    }

    button:not(.suggested-action):not(.destructive-action) {
      border-radius: 100px;
      -gtk-outline-radius: 100px;
      &.text-button,
      &.flat.selection-menu {
        border-radius: 2px;
        -gtk-outline-radius: 2px;
        &.image-button {
          border-radius: 100px;
          -gtk-outline-radius: 100px;
        }
      }
    }

    entry {
      color: $inverted_secondary_fg_color;
      &:focus { color: $inverted_fg_color; }
      &:disabled { color: $insensitive_inverted_secondary_fg_color; }
    }

    .selection-menu {
      padding-left: rem(16px);
      padding-right: rem(16px);
      &, &.popup {
        color: $secondary_selected_fg_color;
        &:hover,
        &:active,
        &:checked { color: $selected_fg_color; }
        &:disabled { color: $insensitive_inverted_secondary_fg_color; }
        &:checked {
          border-image: -gtk-gradient(radial,
                                      center bottom, 0,
                                      center bottom, 0.5,
                                      to($selected_fg_color),
                                      to(transparent))
                                      0 0 2 / 0 0 2px;
          background-color: transparent;
          &:disabled {
            color: $insensitive_selected_fg_color;
            > label { color: inherit; }
          }
        }
      }

      GtkArrow { -GtkArrow-arrow-scaling: 1.0; }

      .arrow {
        -gtk-icon-source: -gtk-icontheme('pan-down-symbolic');
        color: $secondary_selected_fg_color;
      }
    }
  }

  // misc
  .tiled & {
    @extend %tiled_integration;
    transition: none;
  }
  .maximized & {
    @extend %maxd_integration;
    transition: none;
  }

  &.default-decoration {
    min-height: 26.7px;
    padding: 5.3px;
    border-width: 0;

    .title { // fade_effect doesn't work
      color: $inverted_fg_color;
      &:backdrop { color: gtkopacity($inverted_fg_color, 0.4); }
    }

    button.titlebutton {
      min-width: 26.7px;
      min-height: 26.7px;
      margin: 0;
      padding: 0;
      color: $inverted_secondary_fg_color;
      background-size: $image_button_small;
      &:hover,
      &:active { color: $inverted_fg_color; }
      &:backdrop { color: gtkopacity($inverted_fg_color, 0.4); }
    }
  }
}

headerbar {
  // draw borders
  border-width: 1px 0 1px;
  border-style: solid;
  // do not use transparentize
  border-top-color: $top_edge_border_color;
  border-bottom-color: $solid_dark_borders_color;

  // To avoid double-padding, set it only for titlebar in case it
  // is placed on the header-bar.
  &.titlebar,
  .csd &,
  box &:only-child {
    padding: rem(5.3px);
    // draw hilight and shadows
    box-shadow: if($variant == 'light', $header-shadow-light,
                                        $header-shadow-dark);

    .tiled &  { @extend %tiled_integration; }
    .maximized & { @extend %maxd_integration; }
  }

  // override unwanted side-borders
  box &:not(:only-child):first-child,
  box &:not(:only-child):last-child {
    border-left-color: $inverted_dark_color;
    border-right-color: $inverted_dark_color;

    .tiled &,
    .maximized & {
      border-left-color: $panel_bg_color;
      border-right-color: $panel_bg_color;
    }
  }

  box & { // Remove unneeded side shadows with dirty hacks
    &:not(:only-child):last-child {
      &:dir(ltr) {
        box-shadow: if($variant == 'light', $sub-header-shadow-light-ltr,
                                            $sub-header-shadow-dark-ltr);

        .tiled &  { @extend %tiled_integration; }
        .maximized & { @extend %maxd_integration; }
      }
      &:dir(rtl) {
        box-shadow: if($variant == 'light', $sub-header-shadow-light-rtl,
                                            $sub-header-shadow-dark-rtl);

        .tiled &  { @extend %tiled_integration; }
        .maximized & { @extend %maxd_integration; }
      }
    }
  }

  // paned-separator is actually drawn by paned itself
  paned &:not(:only-child):last-child {
    &:dir(ltr) {
      // border-left: 1px solid $solid_dark_borders_color;

      .tiled &  { @extend %tiled_integration; }
      .maximized & { @extend %maxd_integration; }
    }
    &:dir(rtl) {
      // border-right: 1px solid $solid_dark_borders_color;

      .tiled &  { @extend %tiled_integration; }
      .maximized & { @extend %maxd_integration; }
    }
  }
}

headerbar.selection-mode { // selection-mode specific
  box & { // Remove unneeded side shadows with dirty hacks
    &:not(:only-child):last-child {
      &:dir(ltr) {
        box-shadow: if($variant == 'light', $selected-header-shadow-light-ltr,
                                            $selected-header-shadow-dark-ltr);

        .tiled &  { @extend %tiled_integration; }
        .maximized & { @extend %maxd_integration; }
      }
      &:dir(rtl) {
        box-shadow: if($variant == 'light', $selected-header-shadow-light-rtl,
                                            $selected-header-shadow-dark-rtl);

        .tiled &  { @extend %tiled_integration; }
        .maximized & { @extend %maxd_integration; }
      }
    }
  }
}

headerbar,
.titlebar { // set rounded corners
  border-top-left-radius: 2px;
  border-top-right-radius: 2px;

  box &:not(:last-child):not(.titlebar) {
    &:dir(ltr) {
      border-top-left-radius: 2px;
      border-top-right-radius: 0;
    }
    &:dir(rtl) {
      border-top-left-radius: 0;
      border-top-right-radius: 2px;
    }
  }

  box &:last-child:not(.titlebar) {
    &:dir(ltr) { border-top-left-radius: 0; }
    &:dir(rtl) { border-top-right-radius: 0; }
  }
}

// force using rounded corners in case of paned titlebars
window:not(.maximized):not(.tiled) {
  paned.titlebar {
    border-top-left-radius: 2px;
    border-top-right-radius: 2px;

    > headerbar:not(:last-child) {
      &:dir(ltr) {
        border-top-left-radius: 2px;
        border-top-right-radius: 0;
      }
      &:dir(rtl) {
        border-top-left-radius: 0;
        border-top-right-radius: 2px;
      }
    }
    > headerbar:last-child {
      &:dir(ltr) {
        border-top-left-radius: 0;
        border-top-right-radius: 2px;
      }
      &:dir(rtl) {
        border-top-left-radius: 2px;
        border-top-right-radius: 0;
      }
    }
  }
}

// revive top-edge highlight border for SSDs
.ssd decoration {
  .titlebar {
    border-top: 1px solid $highlight_color;
    box-shadow: none;
  }
}

// squared corners when the window is max'd or tiled
%tiled_integration {
  border-radius: 0;
  border-color: $panel_bg_color;
  border-width: 2px 0 0 0;
  border-top-color: $secondary_selected_bg_color;
  background-color: $panel_bg_color;
  box-shadow: none;
  &:backdrop { border-top-color: $track_color; }
}

%maxd_integration {
  border-radius: 0;
  border-color: $panel_bg_color;
  border-width: 1px 0 0 0;
  background-color: $panel_bg_color;
  box-shadow: none;
}


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

.linked.path-bar,
.path-bar {
  button {
    &, &.text-button {
      padding: 0 rem(1.3px) 0;
      -gtk-outline-radius: 2px;
    }
    &.image-button { padding: 0 rem(5.3px) 0; }

    &.text-button.image-button {
      -gtk-outline-radius: 2px;
      label {
        padding-left: 0;
        padding-right: 0;
      }
    }

    &.text-button.image-button {
      label { // FIXME: is it still needed?
        &:last-child { padding-right: rem(5.3px); }
        &:first-child { padding-left: rem(5.3px); }
      }
    }

    image { padding: rem(1.3px) rem(5.3px) 0; }

    &.slider-button, // FIXME: workaround for Nautilus 3.20.0
    &.image-button.text-button.toggle {
      min-height: rem(17.3px);
      padding: 0 rem(1.3px) 0;
      -gtk-outline-radius: 2px;
    }
  }
}


/**************
 * Tree Views *
 **************/

treeview.view {
  @at-root * {
    -GtkTreeView-horizontal-separator: 4;
    -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: $track_color;   // this is actually the tree lines color,
  border-top-color: $borders_color;  // while this is the grid lines color,
                                     // better then nothing

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

  border-radius: 0; // rest border radius in lists

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

  // override foreground colours
  &, entry,
  entry > label {
    color: $secondary_fg_color;
    &:hover,
    &:active,
    &:focus { color: $fg_color; }
    &:selected { color: $selected_fg_color; }
    &:disabled {
      color: $insensitive_fg_color;
      &:selected { color: $insensitive_selected_fg_color; }
    }
  }

  .separator {
    &, &:hover {
      color: transparent;
      background-color: $borders_color;
    }
  }

  // clear backgrounds
  background-color: transparent;
  background-image: none;
  box-shadow: none;

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

  expander {
    arrow {
      -gtk-icon-source: -gtk-icontheme('pan-end-symbolic');
      &:dir(rtl) { -gtk-icon-source: -gtk-icontheme('pan-end-symbolic-rtl'); }
      &:checked { -gtk-icon-source: -gtk-icontheme('pan-down-symbolic'); }
      &:selected {
        color: gtkopacity($selected_fg_color, 0.75);
        &:hover,
        &:active { color: $selected_fg_color; }
      }
    }
  }

  &.progressbar { // progressbar bit in treeviews
    box-shadow: inset 0 -4px $accent_color;
    &:selected { box-shadow: inset 0 -4px $selected_fg_color; }
  }

  &.trough { // progressbar trough in treeviews
    box-shadow: inset 0 -4px gtkalpha($accent_color, 0.2);
    &:selected { box-shadow: inset 0 -4px gtkalpha($selected_fg_color, 0.2); }
  }

  &, paned & { // redraw some stuff for RhythmBox
    background-color: $base_color;
    &:hover,
    row:hover { color: $fg_color; }
    &:selected,
    row:selected { @extend %selected_items; }
  }

  // see tests/testaccel to test
  acceleditor > label { background-color: $selected_bg_color; }

  header {
    button {
      @extend row.activatable;
      min-height: rem(20px);
      padding: 0 rem(6.7px) 0;
      border-style: none solid solid none;
      border-width: 1px;
      border-color: $borders_color;
      border-radius: 0;
      box-shadow: none;
      background-color: $base_color;
      // font-weight: 700;
      color: $tertiary_fg_color;
    }
    &:hover,
    &:active {
      color: $fg_color;
      box-shadow: none;
    }
    &:disabled { background-color: $base_color; }
    &.dnd { @extend column-header.button.dnd; }
  }
  & button:last-child,
  &:last-child button { // treeview-like derived widgets in Banshee
                        // and Evolution
    border-right-style: none;
  }

  &.separator {
    min-height: rem(2px);
    color: transparent;
    background-color: $borders_color;
  }
}

column-header.button.dnd { // for treeview-like derive widgets
  transition: none;
  border-left-style: solid;
  color: $selected_bg_color;
}


/*********
 * Menus *
 *********/

.menubar,
menubar {
  -GtkWidget-window-dragging: true;
  padding: 0;
  box-shadow: $menubar-shadow;
  background-color: $inverted_dark_color;
  color: $inverted_secondary_fg_color; // FIXME: Gtk+3 firefox needs this!

  .tiled &,
  .maximized & {
    background-color: $panel_bg_color;
    box-shadow: none;
    transition: none;
  }

  > menuitem {
    min-height: rem(20px);
    padding: rem(5.3px) rem(8px) rem(6.7px);
    color: $inverted_secondary_fg_color;
    background-color: transparent;
    &:hover { // Seems like it :hover even with keyboard focus
      color: $inverted_fg_color;
      box-shadow: inset 0 -2px $selected_bg_color;
    }
    &:disabled {
      color: $insensitive_inverted_fg_color;
      box-shadow: none;
    }
  }
}

.menu,
.context-menu,
menu {
  margin: rem(4px) 0;
  padding: rem(4px) 0;
  border-width: 1px; // adds borders in a non composited env
  border-style: solid;
  border-color: $base_color transparent transparent;
  background-color: $secondary_base_color;

  .csd & { // axes borders in a composited env
    border-width: 1px;
    border-radius: 2px;
    border-color: $base_color transparent transparent;
  }

  .menuitem,
  menuitem {
    min-height: rem(20px);
    min-width: rem(40px);
    padding: rem(5.3px) rem(8px) rem(6.7px);
    color: $secondary_fg_color;
    font: initial;
    text-shadow: none;
    transition: none;
    &:hover {
      color: $fg_color;
      background-color: gtkalpha(currentColor, 0.1);
      transition: none;
    }
    &:disabled { color: $insensitive_fg_color; }

    // submenu indicators
    arrow {
      min-height: rem(16px);
      min-width: rem(16px);

      &:dir(ltr) {
        -gtk-icon-source: -gtk-icontheme('pan-end-symbolic');
        margin-left: rem(10.7px);
      }
      &:dir(rtl) {
        -gtk-icon-source: -gtk-icontheme('pan-end-symbolic-rtl');
        margin-right: rem(10.7px);
      }
    }

    // avoids labels color being overridden, see
    // https://bugzilla.gnome.org/show_bug.cgi?id=767058
    label {
      &:dir(rtl),
      &:dir(ltr) { color: inherit; }
    }
  }

  > arrow { // overflow buttons
    @extend button.flat;
    min-height: rem(16px);
    min-width: rem(16px);
    padding: rem(4px);
    border-style: none;
    border-radius: 0;
    background-color: $secondary_base_color;
    &.top {
      margin-top: rem(-5.3px);
      -gtk-icon-source: -gtk-icontheme('pan-up-symbolic');
      border-bottom: 1px solid $borders_color;
    }
    &.bottom {
      margin-bottom: rem(-5.3px);
      -gtk-icon-source: -gtk-icontheme('pan-down-symbolic');
      border-top: 1px solid $borders_color;
    }
    &:hover { background-color: $secondary_dark_color; }
    &:disabled {
      color: transparent;
      background-color: transparent;
      border-color: transparent ;
    }
  }

  > separator {
    &:dir(ltr) { margin-left: rem(32px); }
    &:dir(rtl) { margin-right: rem(32px); }
  }
}

menuitem {
  accelerator { color: gtkalpha(currentColor, 0.55); }

  separator {
    color: transparent;
    background: none;
    border-top: 1px solid $borders_color;
    &:dir(ltr) { margin-left: rem(32px); }
    &:dir(rtl) { margin-right: rem(32px); }
  }
}

// round corners for CSD menus
.csd.popup { border-radius: 2px; }


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

popover.background {
  padding: 2px;
  background-color: $secondary_base_color;
  box-shadow:  $z-depth-3;

  .csd &,
  & {
    border: 1px solid;
    border-color: $base_color $secondary_base_color $secondary_base_color;
    border-radius: 2px + 1px;
  }

  &:backdrop { box-shadow: $z-depth-1; }

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

  button menuitem.flat,
  button.flat {
    transition: none;
    padding: 0 rem(10px) 0;
    background-color: transparent;
    background-size: $text_button_small;
    color: $secondary_fg_color;
    font: initial;
    &:hover {
      background-color: transparent; // remove double-bg
      color: $fg_color;
    }

    // FIXME: label padding is ugly
    // vertical padding of GtkMenuItem * 0.5
    label { padding: rem(2.7px) 0 rem(3.3px); }
  }

  button.image-button { padding: rem(6.7px); }

  button.model.image-button { min-height: rem(26.7px); }

  .linked > button {
    @include button(flat-normal);
    @extend %button_array;
    color: $secondary_fg_color;
    &:hover { @include button(flat-hover); }
    &:active { @include button(flat-active); }
    &:disabled { @include button(flat-insensitive); }
    &:checked {
      @include button(flat-checked);
      color: $fg_color;
      background-color: transparent;
    }
    &:checked:disabled { @include button(flat-checked-insensitive); }
  }

  .csd &,
  & {
    &.touch-selection,
    &.magnifier {
      @extend %osd;
      button { @include button(flat-normal); }
    }
  }

  &.osd { @extend %osd; }

  separator { margin: rem(3px) 0; }
}


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

notebook {
  padding: 0;

  &.frame {
    border: 1px solid $solid_light_borders_color;
    transition: none;

    // remove madness borders around header
    > header {
      &, &.frame { border-style: none; }
      @each $_header, $_margin in (top, -1px -1px 0 -1px),
                                  (bottom, 0 -1px -1px -1px),
                                  (left, -1px 0 -1px -1px),
                                  (right, -1px -1px -1px 0) {
        &.#{$_header} { margin: #{$_margin}; }
      }
    }
  }

  > stack {
    transition: none;
    &:only-child {
      border: none;
      background-color: transparent;
      box-shadow: none;
    }

    // the :not(:only-child) is for "hidden" notebooks
    &:not(:only-child),
    &:not(:first-child),
    &:not(:last-child) {
      border: none;
      background-color: $base_color;
      box-shadow: inset 0 0 0 1px $base_color;
    }
  }

  > header {
    $tab_indicator_size: 2px;
    // vertical tab sizing
    $vt_vpadding: rem(5.3px);
    $vt_hpadding: rem(16px);
    // horizontal tab sizing
    $ht_vpadding: rem(5.3px);
    $ht_hpadding: rem(10px);

    background-color: $bg_color;
    tabs { background-color: transparent; }

    @each $_header, $_border in (top, 0 1px),
                                (bottom, 0 -1px),
                                (left, 1px 0),
                                (right, -1px 0) {
      &.#{$_header} {
        // FIXME: outset borders
        box-shadow: #{$_border} $borders_color;
      }
    }

    &.top {
      > tabs {
        margin: 0 rem(6px) -1px rem(6px);
        > tab {
          margin: 0 -1px 0 -1px; // 1px horizontal overlap
          padding: $vt_vpadding $vt_hpadding;
          border-bottom-width: $tab_indicator_size;
          box-shadow: none;
          &.reorderable-page {
            padding-left: rem(10px);  // for a nicer close button
            padding-right: rem(10px); // placement
            border-left-width: 1px;
            border-right-width: 1px;
          }
        }
      }
    }
    &.bottom {
      > tabs {
        margin: -1px rem(6px) 0 rem(6px);
        > tab {
          margin: 0 -1px 0 -1px;
          padding: $vt_vpadding $vt_hpadding;
          border-top-width: $tab_indicator_size;
          box-shadow: none;
          &.reorderable-page {
            padding-left: rem(16px);
            padding-right: rem(16px);
            border-left-width: 1px;
            border-right-width: 1px;
          }
        }
      }
    }
    &.left {
      > tabs {
        margin: rem(6px) -1px rem(6px) 0;
        > tab {
          margin: -1px 0 -1px 0; // 1px vertical overlap
          padding: $ht_vpadding $ht_hpadding;
          border-right-width: $tab_indicator_size;
          box-shadow: none;
          &.reorderable-page {
            border-bottom-width: 1px;
            border-top-width: 1px;
          }
        }
      }
    }
    &.right {
      > tabs {
        margin: rem(6px) 0 rem(6px) -1px;
        > tab {
          margin: -1px 0 -1px 0;
          padding: $ht_vpadding $ht_hpadding;
          border-left-width: $tab_indicator_size;
          box-shadow: none;
          &.reorderable-page {
            border-bottom-width: 1px;
            border-top-width: 1px;
          }
        }
      }
    }

    // Reorderable-page
    @each $_tab, $_border in (top, bottom),
                             (bottom, top),
                             (left, right),
                             (right, left) {
      &.#{$_tab} tab.reorderable-page {
        border-#{$_border}-width: 2px;
        border-#{$_border}-color: transparent;
        &:hover {
          border-color: $borders_color;
          border-#{$_border}-width: 2px;
          border-#{$_border}-color: $borders_color;
          background-color: $base_color;
          box-shadow: none;
        }
        &:checked {
          border-color: $borders_color;
          border-#{$_border}-width: 2px;
          border-#{$_border}-color: $selected_bg_color;
          background-color: $base_color;
          box-shadow: if($variant == 'light', $tab-shadow-light,
                                              $tab-shadow-dark);
        }
      }
    }

    // Arrow buttons
    &.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 {
      transition: none;
      min-height: rem(16px);
      min-width: rem(16px);
      margin: 0 rem(6.7px);
      border-radius: 0;
      color: $tertiary_fg_color;
      &:hover,
      &:active { color: $fg_color; }
      &:disabled { color: $insensitive_fg_color; }
    }

    &.top, &.bottom,
    &.left, &.right { // button outside the tabs
      button {
        min-height: rem(16px);
        min-width: rem(16px);
        padding: 0;
        border-radius: 100px;
        -gtk-outline-radius: 100px;
        & > image { padding: rem(6.7px); }
      }
    }
  }

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

    outline-offset: rem(-6px);

    // here's the interesting stuff
    &:hover { border-color: $track_color; }
    &:checked { border-color: $selected_bg_color; }

    label { // tab text
      padding: rem(1.3px);
      font-weight: 700;
      color: $tertiary_fg_color;
    }
    &.reorderable-page label { // reorderable-page tab text
      padding: rem(5.3px) 0 rem(5.3px);
    }
    &:hover label {
      // hover tab text
      color: $fg_color;
    }
    &:checked label {
      // active tab text
      color: $fg_color;
    }

    button { // tab close button
      @include button(flat-normal);
      min-width: rem(16px);
      min-height: rem(16px);
      padding: 0;
      border-radius: 100px;
      -gtk-outline-radius: 100px;
      background-size: $image_button_small;
      color: $tertiary_fg_color;
      &:hover { @include button(flat-hover); }
      &:active { @include button(flat-active); }
      &:disabled { @include button(flat-insensitive); }
      & > image { // this is a hack which makes tabs grow
        padding: rem(6.7px);
      }
    }
    &:hover button,
    &:checked button { // close button colours
      color: $fg_color;
      image { color: $fg_color; }
    }
    &:disabled button {
      color: $insensitive_fg_color;
      image { color: $insensitive_fg_color; }
    }

    // special case for Gedit's tab 'close' button
    button.flat.image-button.small-button {
      min-width: rem(16px);
      min-height: rem(16px);
      padding: 0;
      // weird wdiget gets in our way
      & > widget > box > image { padding: rem(6.7px); }
    }
  }

  &:not(.reorderable-page) > entry { @extend entry.flat; }
}


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

$_slider_min_width: rem(12px);
$_slider_min_length: rem(32px);

@keyframes slow_down_vert {
  from {min-width: $_slider_min_width - rem(6px); }
  to { min-width: $_slider_min_width; }
}

@keyframes slow_down_horz {
  from {min-height: $_slider_min_width - rem(6px); }
  to { min-height: $_slider_min_width; }
}

scrollbar,
.scrollbar {
  // disable steppers
  @at-root * {
    -GtkScrollbar-has-backward-stepper: false;
    -GtkScrollbar-has-forward-stepper: false;
  }

  background-color: gtkopacity($base_color, 0.55);
  transition-duration: 0.2s;

  // scrollbar border
  &.top,
  &.bottom,
  &.left,
  &.right {
    &, .trough { border: none; }
  }

  // slider
  slider,
  .slider {
    margin: 0;
    border-radius: 0;
    border: 0 none transparent;
    background-color: gtkopacity($tertiary_fg_color, 0.55);
    &:hover { background-color: gtkopacity($secondary_fg_color, 0.55); }
    &:active { background-color: $fg_color; }
    &:disabled { opacity: 0.4; }
  }

  &.fine-tune slider { margin: 0; }

  &.vertical {
    slider,
    .slider {
      min-width: $_slider_min_width;
      min-height: $_slider_min_length;
      margin: 0;
    }
    &.fine-tune slider { margin: 0; }
  }
  &.horizontal {
    slider,
    .slider {
      min-width: $_slider_min_length;
      min-height: $_slider_min_width;
      margin: 0;
    }
    &.fine-tune slider { margin: 0; }
  }

  &.overlay-indicator {
    &:not(.dragging):not(.hovering) { // Overlay scrolling indicator
      border-color: transparent;
      background-color: transparent;

      slider {
        margin: 0;
        border: 0 none transparent;
      }

      button {
        min-width: $_slider_min_width;
        min-height: $_slider_min_width;
        background-color: gtkopacity($tertiary_fg_color, 0.55);
        border-radius: 0;
        border: none;
        -gtk-icon-source: none;
      }

      // w/o the following margin tweaks the slider shrinks
      // when hovering/dragging
      &.vertical {
        slider {
          min-width: $_slider_min_width - rem(6px);
          min-height: $_slider_min_length;
          margin: 0;
        }

        button {
          min-width: rem(6px);
          margin: 0;
        }
      }

      &.horizontal {
        slider {
          min-width: $_slider_min_length;
          min-height: $_slider_min_width - rem(6px);
          margin: 0;
        }

        button {
          min-height: rem(6px);
          margin: 0;
        }
      }
    }

    &.dragging,
    &.hovering { opacity: 0.8; }

    &.hovering { // slow-down when deforming
      &.vertical slider { animation: slow_down_vert 0.2s linear forwards; }
      &.horizontal slider { animation: slow_down_horz 0.2s linear forwards; }
    }
  }
}


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

switch {
  outline-offset: rem(-4px);
  font-size: 0;
  // similar to the scale
  border: rem(10px) solid transparent;
  border-radius: 100px;
  -gtk-outline-radius: 100px;
  background-color: $track_color;

  &:disabled { color: $insensitive_fg_color; }
  &:checked {
    background-color: gtkopacity($selected_bg_color, 0.2);
    &:disabled { background-color: gtkopacity($selected_bg_color, 0.2); }
  }
  &:disabled {
    color: $insensitive_fg_color;
    background-color: $track_color;
  }

  // slider styling
  // switch slider doesn't respond to its own states
  // but relies on the switch ones
  slider {
    @include button(normal);
    min-width: rem(20px);
    min-height: rem(20px);
    margin: rem(-4px) rem(-1px);
    padding: 0;
    border-radius: 100px;
    -gtk-outline-radius: 100px;
  }
  &:hover slider {
    @include button(hover);
    background-image: linear-gradient(to bottom,
                                      gtkalpha($selected_fg_color, 0.2),
                                      gtkalpha($selected_fg_color, 0.2));
  }
  &:checked slider { @include button(checked); }
  &:checked:hover slider {
    @include button(checked);
    background-image: linear-gradient(to bottom,
                                      gtkalpha($selected_fg_color, 0.2),
                                      gtkalpha($selected_fg_color, 0.2));
    box-shadow: $z-depth-2,
                inset 0 1px $highlight_color;
  }
  &:checked:disabled slider {
    @include button(checked-insensitive);
    // do not use any transparentize
    background-color: if($variant == 'light', #F0F2F3, #3F4E56);
    background-image: none;
    box-shadow: none;
  }
  &:disabled slider {
    background-color: if($variant == 'light', #F0F2F3, #3F4E56);
    background-image: none;
    box-shadow: none;
 }

  row:selected & { // return to monochrome
    background-color: $bg_color;
    &:checked {
      background-color: $secondary_dark_color;
      &:disabled { background-color: $secondary_dark_color; }
    }

    slider { background-color: $bg_color; }
    &:hover slider {
      background-image: linear-gradient(to bottom,
                                        gtkalpha($selected_fg_color, 0.2),
                                        gtkalpha($selected_fg_color, 0.2));
    }
    &:checked slider { background-color: $base_color; }
    &:checked:disabled slider { background-color: $secondary_dark_color; }
  }

  // special case inside the grid container,
  // need to protect geometry by using pixmaps images...
  grid & {
    margin: rem(6px) rem(5px);
    font-size: 0;
    outline-color: transparent;

    slider {
      min-width: rem(40px);
      min-height: rem(20px);
    }

    // reset all of default troughs
    &,
    &:hover,
    &:checked,
    &:checked:hover,
    &:checked:disabled,
    &:disabled {
      margin: rem(6px) rem(5px);
      border: none;
      color: transparent;
      background: none;
      background-image: none;
      background-size: 40px 20px;
      background-repeat: no-repeat;
      background-position: right center;
      box-shadow: none;

      &:dir(rtl) { background-position: left center; }
    }

    // reset all of default sliders
    slider,
    &:hover slider,
    &:checked slider,
    &:checked:hover slider,
    &:checked:disabled slider,
    &:disabled slider {
      margin: 0;
      border: none;
      border-radius: 0;
      color: transparent;
      background: none;
      background-image: none;
      background-size: 40px 20px;
      background-repeat: no-repeat;
      background-position: right center;
      box-shadow: none;

      &:dir(rtl) { background-position: left center; }
    }

    // use ugly pixmaps
    &:not(:hover):not(:checked):not(:disabled) {
      background-image: -gtk-scaled(
                        url("assets/toggle-off#{$asset_suffix}.png"),
                        url("assets/toggle-off#{$asset_suffix}@2.png"));
    }
    &:hover {
      background-image: -gtk-scaled(
                        url("assets/toggle-off-hover#{$asset_suffix}.png"),
                        url("assets/toggle-off-hover#{$asset_suffix}@2.png"));
    }
    &:checked {
      background-image: -gtk-scaled(url("assets/toggle-on.png"),
                                    url("assets/toggle-on@2.png"));
      &:hover {
        background-image: -gtk-scaled(url("assets/toggle-on-hover.png"),
                                      url("assets/toggle-on-hover@2.png"));
      }
      &:disabled {
        background-image: -gtk-scaled(
                          url("assets/toggle-on-insensitive#{$asset_suffix}.png"),
                          url("assets/toggle-on-insensitive#{$asset_suffix}@2.png"));
      }
    }
    &:disabled {
      background-image: -gtk-scaled(
                        url("assets/toggle-off-insensitive#{$asset_suffix}.png"),
                        url("assets/toggle-off-insensitive#{$asset_suffix}@2.png"));
    }
  }
}


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

@keyframes check_radio_hover {
  from {
    background-image: -gtk-gradient(radial,
                                    center center, 0,
                                    center center, 0.001,
                                    to(gtkalpha($secondary_fg_color, 0.1)),
                                    to(transparent));
  }
  to {
    background-image: -gtk-gradient(radial,
                                    center center, 0,
                                    center center, 0.5,
                                    to(gtkalpha($secondary_fg_color, 0.1)),
                                    to(transparent));
  }
}

@keyframes check_radio_active {
  from {
    background-image: -gtk-gradient(radial,
                                    center center, 0,
                                    center center, 0.001,
                                    to(gtkalpha($selected_bg_color, 0.1)),
                                    to(transparent));
  }
  to {
    background-image: -gtk-gradient(radial,
                                    center center, 0,
                                    center center, 0.5,
                                    to(gtkalpha($selected_bg_color, 0.1)),
                                    to(transparent));
  }
}

@keyframes check_radio_active_reverse {
  from {
    background-image: -gtk-gradient(radial,
                                    center center, 0,
                                    center center, 0.5,
                                    to(gtkalpha($selected_bg_color, 0.2)),
                                    to(transparent));
  }
  to {
    background-image: -gtk-gradient(radial,
                                    center center, 0,
                                    center center, 0.001,
                                    to(gtkalpha($selected_bg_color, 0)),
                                    to(transparent));
  }
}

// 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-active'),
                  (':active', '-unchecked-active'),
                  (':disabled','-unchecked-insensitive'),
                  (':indeterminate', '-mixed'),
                  (':indeterminate:hover', '-mixed-active'),
                  (':indeterminate:active', '-mixed-active'),
                  (':indeterminate:disabled', '-mixed-insensitive'),
                  (':checked', '-checked'),
                  (':checked:hover', '-checked-active'),
                  (':checked:active', '-checked-active'),
                  (':checked:disabled','-checked-insensitive') {
    #{$w}#{$s},
    .#{$w}#{$s} {
      -gtk-icon-source: -gtk-scaled(url("assets/#{$a}#{$as}#{$asset_suffix}.png"),
                                    url("assets/#{$a}#{$as}#{$asset_suffix}@2.png"));
      -gtk-icon-shadow: none;
    }
  }

  // menu
  @each $s,$as in ('',''),
                  // (':active', '-checked'),
                  (':disabled','-insensitive'),
                  (':indeterminate', '-mixed'),
                  // (':indeterminate:active', '-mixed'),
                  (':indeterminate:disabled', '-mixed-insensitive'),
                  (':checked', '-checked'),
                  // (':checked:active', '-checked'),
                  (':checked:disabled','-checked-insensitive') {
    menu menuitem #{$w}#{$s},
    menu menuitem .#{$w}#{$s} {
      -gtk-icon-source: -gtk-scaled(url("assets/#{$a}#{$as}-symbolic#{$asset_suffix}.png"),
                                    url("assets/#{$a}#{$as}-symbolic#{$asset_suffix}@2.png"));
      -gtk-icon-shadow: none;
      &:hover {
        -gtk-icon-source: -gtk-scaled(url("assets/#{$a}#{$as}-symbolic#{$asset_suffix}.png"),
                                      url("assets/#{$a}#{$as}-symbolic#{$asset_suffix}@2.png"));
        animation: none;
        -gtk-icon-shadow: none;
        transition: none;
      }
    }
  }
}

// check/radio inside treeview
treeview.view check,
treeview.view radio {
  &, &:only-child {
    // margin: rem(-6.7px);
    // padding: rem(6.7px);
    padding: 0; // FIXME: negative margin doesn't work.
  }
}

// check/radio inside selected-rows
@each $w,$a in ('check', 'checkbox'),
               ('radio','radio') {

  // standard checks and radios
  @each $s,$as in ('','-unchecked'),
                  (':active', '-unchecked'),
                  (':indeterminate', '-mixed'),
                  (':indeterminate:active', '-mixed'),
                  (':checked', '-checked'),
                  (':checked:active', '-checked') {
    treeview.view,
    row,
    row.activatable {
      #{$w}:selected#{$s},
      #{$w}:selected:focus#{$s} {
        -gtk-icon-source: -gtk-scaled(url("assets/#{$a}#{$as}-selected.png"),
                                      url("assets/#{$a}#{$as}-selected@2.png"));
        -gtk-icon-shadow: none;
      }
      // use dark variant for insensitive states
      #{$w}:selected:disabled,
      #{$w}:selected:focus:disabled {
        -gtk-icon-source: -gtk-scaled(url("assets/#{$a}-unchecked-insensitive-dark.png"),
                                      url("assets/#{$a}-unchecked-insensitive-dark@2.png"));
      }
      #{$w}:selected:indeterminate:disabled,
      #{$w}:selected:focus:indeterminate:disabled {
        -gtk-icon-source: -gtk-scaled(url("assets/#{$a}-mixed-insensitive-dark.png"),
                                      url("assets/#{$a}-mixed-insensitive-dark@2.png"));
      }
      #{$w}:selected:checked:disabled,
      #{$w}:selected:focus:checked:disabled {
        -gtk-icon-source: -gtk-scaled(url("assets/#{$a}-checked-insensitive-dark.png"),
                                      url("assets/#{$a}-checked-insensitive-dark@2.png"));
      }
    }
  }
}

// selection-mode
@each $s,$as in ('','-selectionmode'),
                  (':hover', '-active-selectionmode'),
                  (':active', '-active-selectionmode'),
                  (':disabled', '-insensitive-selectionmode'),
                  (':checked', '-checked-selectionmode'),
                  (':checked:hover', '-checked-active-selectionmode'),
                  (':checked:active', '-checked-active-selectionmode'),
                  (':disabled:checked', '-checked-insensitive-selectionmode') {
  .view.content-view check#{$s}:not( list) {
    -gtk-icon-source: -gtk-scaled(url("assets/checkbox#{$as}#{$asset_suffix}.png"),
                                  url("assets/checkbox#{$as}#{$asset_suffix}@2.png"));
    background-color: transparent;
  }
}

checkbutton.text-button,
radiobutton.text-button {
  // this is for a nice focus on check and radios text
  padding: rem(2.7px) rem(6.7px);
  outline-offset: 0;
  color: $secondary_fg_color;
  &:hover,
  &:active,
  &:checked { color: $fg_color; }
  &:disabled,
  &:disabled:active,
  &:disabled:indeterminate {
    // set insensitive color, which is overriden otherwise
    // color: $insensitive_fg_color;
  }
}

radio,
.radio,
check,
.check {
  min-width: rem(16px);
  min-height: rem(16px);
  // margin: 0 rem(6.7px) 0 rem(6.7px);
  margin: rem(-10px) rem(-3.3px);
  padding: rem(10px);

  &:hover {
    animation: check_radio_hover 0.2s cubic-bezier(0.4, 0, 0.2, 1) forwards;
  }
  &:active {
    animation: check_radio_active_reverse 0.15s cubic-bezier(0.4, 0, 0.2, 1) forwards;
    transition-duration: 0.15s;
  }
  &:hover:checked,
  &:hover:indeterminate {
    animation: check_radio_active 0.2s cubic-bezier(0.4, 0, 0.2, 1) forwards;
  }

  menu menuitem & {
    min-width: rem(16px);
    min-height: rem(16px);
    margin: 0;
    padding: 0;
    &:dir(ltr) { margin-right: rem(8px); }
    &:dir(rtl) { margin-left: rem(8px); }

    &, &:hover, &:disabled { //FIXME: use button reset mixin
      border-color: transparent;
      background-image: none;
      background-color: transparent;
      box-shadow: none;
      -gtk-icon-shadow: none;
      color: inherit;
      animation: none;
    }
  }
}


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

@keyframes scale_enlarge {
  from { background-size: $scale; }
  to { background-size: 100%; }
}

%scale_trough {
  border: 1px solid transparent;
  border-radius: 0;
  background-color: $track_color;
  box-shadow: none;
  &:disabled {
    color: $insensitive_fg_color;
    background-color: $track_color;
  }

  &:backdrop {
  }

  // OSD
  .osd & {
  }
}

%scale_highlight {
  border: 1px solid transparent;
  border-radius: 0;
  background-color: $accent_color;
  &:disabled {
    color: $insensitive_fg_color;
    background-color: $track_color;
  }

  &:backdrop {
  }

  // OSD
  .osd & {
  }
}

$_marks_lenght: 6px;
$_marks_distance: 6px;

scale {
  // remove ugly outlines
  // outline-offset: -4px;
  // -gtk-outline-radius: 100px;
  outline-offset: 0;
  outline-width: 0;

  min-height: 10px;
  min-width: 10px;
  padding: 10px;

  &.fine-tune {
    // remove ugly outlines
    // outline-offset: rem(-4px);
    outline-offset: 0;
    outline-width: 0;
    &.horizontal {
      padding-top: 9px;
      padding-bottom: 9px;
      min-height: 10px;
    }

    &.vertical {
      padding-left: 9px;
      padding-right: 9px;
      min-width: 10px;
    }

    // to make the trough grow in fine-tune mode
    slider { margin: -9px; }

    highlight,
    fill,
    trough {
    }
  }

  slider {
    min-height: 20px;
    min-width: 20px;
    margin: -9px;

    &:not(:hover):not(:active) { background-size: $scale; }
    // @include entry(normal);
    // border-radius: 50%;
    // background-color: $success_color;
    @each $s,$as in ('',''),
                    // (':hover','-hover'),
                    (':active','-active'),
                    (':disabled','-insensitive') {
      &#{$s} {
        $_url: 'assets/slider#{$as}#{$asset_suffix}';
        border-style: none;
        border-radius: 0;
        background-color: transparent;
        background-image: -gtk-scaled(url('#{$_url}.png'),
                                      url('#{$_url}@2.png'));
        background-repeat: no-repeat;
        background-position: center;
        box-shadow: none;
      }
    }
    &:hover {
      animation: scale_enlarge 0.2s cubic-bezier(0.4, 0, 0.2, 1) forwards;
    }
    &:disabled {
    }
    // OSD sliders
    .osd & {
    }
  }

  // the backing bit sizing
  trough,
  fill,
  highlight {
    min-height: 2px;
    min-width: 2px;
    border-radius: 0;
    border-width: 0;
  }

  // the backing bit styling
  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;

    background-color: $accent_fill_color;

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

  // same opacity value with dim-label
  value { color: gtkalpha(currentColor, 0.55); }

  separator {
    color: transparent;
    background-color: $track_color;
  }

  // scales on selected list rows
  row:selected & {
  }
}

scale { // marks color
  marks {
    color: gtkalpha(currentColor, 0.55);
    @each $marks_class, $marks_pos, $marks_margin in (top, top, bottom),
                                                     (bottom, bottom, top),
                                                     (top, left, right),
                                                     (bottom, right, left) {
      &.#{$marks_class} {
        margin-#{$marks_margin}: $_marks_distance;
        margin-#{$marks_pos}: -($_marks_distance + $_marks_lenght);
      }
    }
  }

  &.fine-tune marks {
    @each $marks_class, $marks_pos, $marks_margin in (top, top, bottom),
                                                     (bottom, bottom, top),
                                                     (top, left, right),
                                                     (bottom, right, left) {
      &.#{$marks_class} {
        margin-#{$marks_margin}: $_marks_distance;
        margin-#{$marks_pos}: -($_marks_distance + $_marks_lenght - 3px);
      }
    }
  }

  &.horizontal {
    indicator {
      min-height: $_marks_lenght;
      min-width: 1px;
    }

    &.fine-tune indicator { min-height: ($_marks_lenght - 3px); }
  }

  &.vertical {
    indicator {
      min-height: 1px;
      min-width: $_marks_lenght;
    }

    &.fine-tune indicator { min-width: ($_marks_lenght - 3px); }
  }
}

// scale with marks
@each $d,$dn in ('horizontal', 'horz'),
                ('vertical', 'vert') {
  @each $ws,$w,$we in  (':last-child:not(:only-child)',
                        'scale-has-marks-above', 'scale_marks_above'),
                       (':first-child:not(:only-child)',
                        'scale-has-marks-below', 'scale_marks_below') {
    scale.#{$d} {
      %#{$w}-#{$dn},
      contents#{$ws} > trough > slider {
        @each $s,$as in ('',''),
                        // (':hover','-hover'),
                        (':active','-active'),
                        (':disabled','-insensitive') {
          &#{$s} {
            @extend %#{$we}_#{$dn}; // negative margin makes trough shrinking
            $_url: 'assets/slider-#{$dn}-#{$w}#{$as}#{$asset_suffix}';
            border-style: none;
            border-radius: 0;
            background-color: transparent;
            background-image: -gtk-scaled(url('#{$_url}.png'),
                                          url('#{$_url}@2.png'));
            background-repeat: no-repeat;
            background-position: center;
            box-shadow: none;
          }
        }
      }
      &.fine-tune {
        %#{$w}-#{$dn}-fine-tune,
        contents#{$ws} > tough > slider {
          @each $s,$as in ('',''),
                          // (':hover','-hover'),
                          (':active','-active'),
                          (':disabled','-insensitive') {
            &#{$s} { @extend %#{$we}_#{$dn}_ft; }
	  }
        }
      }
    }
  }
}

scale { // scales for colour
  &.color {
    min-height: 0;
    min-width: 0;

    // not actual trough colour
    trough {
      min-width: 2px;
      min-height: 2px;
      border-radius: 0;
      background-color: transparent;
    }

    &.horizontal {
      padding: 0 0 10px 0;

      trough { padding-bottom: 5px; }

      slider {
        &, &:hover, &:disabled {
          @extend %scale-has-marks-above-horz;
          margin-top: 5px;
          margin-bottom: -10px;
        }
      }
    }

    &.vertical {
      &:dir(ltr) {
        padding: 0 0 0 10px;

        trough { padding-left: 5px; }

        slider {
          &, &:hover, &:disabled {
            @extend %scale-has-marks-below-vert;
            margin-left: -10px;
            margin-right: 5px;
          }
        }
      }

      &:dir(rtl) {
        padding: 0 10px 0 0;

        trough { padding-right: 5px; }

        slider {
          &, &:hover, &:disabled {
            @extend %scale-has-marks-above-vert;
            margin-left: 5px;
            margin-right: -10px;
          }
        }
      }
    }

    &.fine-tune {
      &.horizontal {
        padding: 0 0 10px 0;

        trough { padding-bottom: 5px; }

        slider {
          @extend %scale-has-marks-above-horz-fine-tune;
          margin-top: 5px;
          margin-bottom: -10px;
        }
      }

      &.vertical {
        &:dir(ltr) {
          padding: 0 0 0 10px;

          trough { padding-left: 5px; }

          slider {
            @extend %scale-has-marks-below-vert-fine-tune;
            margin-left: -10px;
            margin-right: 5px;
          }
        }

        &:dir(rtl) {
          padding: 0 10px 0 0;

          trough { padding-right: 5px; }

          slider {
            @extend %scale-has-marks-above-vert-fine-tune;
            margin-left: 5px;
            margin-right: -10px;
          }
        }
      }
    }
  }
}

%scale_marks_above_horz { margin: -15px -10px -10px -10px; }
%scale_marks_below_horz { margin: -10px -10px -15px -10px; }
%scale_marks_above_vert { margin: -10px -10px -10px -15px; }
%scale_marks_below_vert { margin: -10px -15px -10px -10px; }
%scale_marks_above_horz_ft { margin: -15px -10px -10px -10px; }
%scale_marks_below_horz_ft { margin: -10px -10px -15px -10px; }
%scale_marks_above_vert_ft { margin: -10px -10px -10px -15px; }
%scale_marks_below_vert_ft { margin: -10px -15px -10px -10px; }


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

progressbar {
  // sizing
  &.horizontal {
    trough,
    progress { min-height: 4px; }
  }

  &.vertical {
    trough,
    progress { min-width: 4px; }
  }

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


  // FIXME: insensitive state missing and some other state
  // should be set probably
  font-size: 90%;
  color: $tertiary_fg_color;

  trough {
    box-shadow: none;
    border-radius: 0;
    background-color: gtkopacity($accent_color, 0.2);
  }

  progress {
    box-shadow: none;
    border-radius: 0;
    background-color: $accent_color;
    &.left {
      border-top-left-radius: 0;
      border-bottom-left-radius: 0;
    }
    &.right {
      border-top-right-radius: 0;
      border-bottom-right-radius: 0;
    }
    &.top {
      border-top-left-radius: 0;
      border-top-right-radius: 0;
    }
    &.bottom {
      border-bottom-left-radius: 0;
      border-bottom-right-radius: 0;
    }
  }

  &.osd {
    min-width: 4px;
    min-height: 4px;
    trough {
      border-style: none;
      box-shadow: none;
      background-color: gtkopacity($accent_color, 0.2);
    }
    progress {
      background-image: none;
      background-color: $accent_color;
      border-style: none;
      border-radius: 0;
    }
  }
}

%entry_progressbar { // progress inside entry
  margin: -10px -6px;
  border-style: none none solid;
  border-width: 2px;
  border-image: -gtk-gradient(radial,
                              center bottom, 0,
                              center bottom, 0.5,
                              to($accent_color),
                              to(transparent))
                              0 0 2 / 0 0 2px;
  border-radius: 0;
  box-shadow: none;
  background-color: transparent;
  background-image: none;
}


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

levelbar {
  box-shadow: $z-depth-1; // needs to be set here to avoid clipping

  block {
    min-width: rem(36px);
    min-height: rem(4px);
  }

  &.vertical block {
    min-width: rem(4px);
    min-height: rem(36px);
  }

  trough {
    padding: rem(2px);
    border-radius: 2px;
    box-shadow: $z-depth-1;
    &:disabled { box-shadow: none; }
    &.horizontal { padding: rem(2px) rem(1px); }
    &.vertical { padding: rem(1px) rem(2px); }
  }

  &.horizontal.discrete block { margin: 0 rem(1px); }
  &.vertical.discrete block { margin: rem(1px) 0; }

  block {
    border-radius: 0;
    border: none;
    box-shadow: none;
  }

  block.low { background-color: $warning_color; }

  block:not(.empty),
  block.high { background-color: $selected_bg_color; }

  block.full { background-color: $success_color; }

  block.empty { background-color: $track_color; }
}


/****************
 * Print dialog *
*****************/

printdialog {
  paper {
    padding: 0;
    color: $fg_color;
    border: 1px solid $borders_color;
    background-color: white;
  }

  .dialog-action-box { margin: rem(12px); }
}


/**********
 * Frames *
 **********/

frame > border,
.frame {
  margin: 0;
  padding: 0;
  border-radius: 0;
  border: 1px solid $borders_color;
  box-shadow: none;
  &.flat { border-style: none; }
}

actionbar > frame > border { border-width: 1px 0 0; }

actionbar > revealer > box {
  padding: rem(5.3px);
  border-top: 1px solid $borders_color;
}

placessidebar,
scrolledwindow {
  viewport.frame { // avoid double borders when viewport inside
                   // scrolled window
    border-style: none;
  }

  // This is used by GtkScrolledWindow,
  // when content is touch-dragged past boundaries.
  // This draws a box on top of the content, the size changes programmatically.
  overshoot {
    &.top {
      @include overshoot(top);
    }
    &.bottom {
    @include overshoot(bottom);
    }
    &.left {
      @include overshoot(left);
    }
    &.right {
      @include overshoot(right);
    }
  }

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

  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: $base_color;

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

// vbox and hbox separators
separator {
  // always disable separators
  color: transparent;
  background-color: $borders_color;
  min-width: 1px;
  min-height: 1px;
}


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

list {
  border-color: $borders_color;
  background-color: $base_color;
}

row {
  padding: 2px;
}

row.activatable {
  // let's take care of background colors
  background-image: -gtk-gradient(radial,
                                    center center, 0,
                                    center center, 0.5,
                                    to(gtkalpha(currentColor, 0)),
                                    to(transparent)),
                      linear-gradient(to bottom, gtkalpha(currentColor, 0), gtkalpha(currentColor, 0));
  background-repeat: no-repeat;
  background-position: center, center;
  background-size: $text_button_large;
  &.has-open-popup, // this is for indicating which sidebar row
                    // generated a popover
  &:hover {         // see https://bugzilla.gnome.org/show_bug.cgi?id=754411
    transition: none;
    background-image: -gtk-gradient(radial,
                                    center center, 0,
                                    center center, 0.5,
                                    to(gtkalpha(currentColor, 0)),
                                    to(transparent)),
                      linear-gradient(to bottom, gtkalpha(currentColor, 0.05), gtkalpha(currentColor, 0.05));
  }

  &:active {
    animation: list_ripple_effect 0.2s cubic-bezier(0.4, 0, 0.2, 1) forwards;
  }
}

// button spacing
row {
  & button.image-button {
    padding: rem(8px);
    background-size: $image_button_small;
  }

  & button.circular {
    min-width: rem(13.3px);
    min-height: rem(13.3px);
    padding: rem(8px);
    background-size: $image_button_small;
  }
}

row:selected {
  @extend %selected_items;
  button {
    &:disabled { color: $insensitive_secondary_selected_fg_color; }
    &.flat {
      color: $secondary_selected_fg_color;
      &:hover, &:active { color: $selected_fg_color; }
      &:disabled { color: $insensitive_secondary_selected_fg_color; }
    }
  }
}

// transition
row {
  &:hover { transition: none; }
}


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

.app-notification,
.app-notification.frame {
  @extend %osd;
  @extend toolbar.osd;
  button {
  }
  border { border: none; }
}


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

expander {
  padding: rem(2.7px) rem(4px) rem(3.3px);

  arrow {
    -gtk-icon-source: -gtk-icontheme('pan-end-symbolic');
    min-width: rem(16px);
    min-height: rem(16px);
    &:dir(rtl) { -gtk-icon-source: -gtk-icontheme('pan-end-symbolic-rtl'); }
    &:checked { -gtk-icon-source: -gtk-icontheme('pan-down-symbolic'); }
    &:not(:hover):not(:active) { color: gtkalpha(currentColor, 0.75); }
    &:selected { color: $selected_fg_color; }
  }

  label {
    color: $secondary_fg_color;
    &:hover,
    &:active { color: $fg_color; }
    &:selected { color: $selected_fg_color; }
  }
}


/************
 * Calendar *
 ***********/

calendar {
  margin: rem(8px) 0;
  padding: rem(5.3px) rem(1.3px) rem(2.7px);
  border: 1px solid $borders_color;
  color: $fg_color;
  &:selected {
    border: none;
    border-radius: 100px;
    color: $selected_bg_color;
    background-color: transparent;
    background-image: -gtk-scaled(url("assets/calendar-day-selected.png"),
                                  url("assets/calendar-day-selected@2.png"));
    background-size: rem(19.3px) rem(19.3px);
    background-position: center top;
    background-repeat: no-repeat;
  }

  &.header {
    border: 1px solid transparent;
    border-bottom-color: $borders_color;
    border-radius: 0;
  }

  &.button,
  &.header.button {
    @include button(flat-normal);
    color: gtkalpha(currentColor, 0.20);
    background-size: $image_button_small;
    &:hover { @include button(flat-hover); }
    &:active { @include button(flat-active); }
    &:disabled { @include button(flat-insensitive); }
  }

  &:indeterminate { color: gtkalpha(currentColor, 0.20); }
  &.highlight {
    color: gtkalpha(currentColor, 0.55);
    font-size: 90%;
    font-weight: 500;
  }
}


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

messagedialog { // Message Dialog styling
  .titlebar {
    min-height: rem(20px);
    border-style: none;
    border-top-left-radius: 2px;
    border-top-right-radius: 2px;
    color: $inverted_secondary_fg_color;
    background-color: $inverted_dark_color;
  }

  entry {
    &, &:focus {
      color: $inverted_fg_color;
      caret-color: $inverted_fg_color;
    }
    &:disabled { color: $insensitive_inverted_fg_color; }
  }

  button { // set foregrounds for fallback-mode
    color: $secondary_accent_color;
    &:hover,
    &:active,
    &:checked { color: $accent_color; }
    &:disabled { color: $insensitive_inverted_fg_color; }
  }
  .linked > button {
    border: 2px solid transparent;
    border-radius: 2px;
    border-image: none;
    box-shadow: none;
  }

  @each $s,$as in ('','-unchecked'),
                  (':hover', '-unchecked-active'),
                  (':active', '-unchecked-active'),
                  (':disabled','-unchecked-insensitive'),
                  (':indeterminate', '-mixed'),
                  (':indeterminate:hover', '-mixed-active'),
                  (':indeterminate:active', '-mixed-active'),
                  (':indeterminate:disabled', '-mixed-insensitive'),
                  (':checked', '-checked'),
                  (':checked:hover', '-checked-active'),
                  (':checked:active', '-checked-active'),
                  (':checked:disabled','-checked-insensitive') {
    check#{$s} { // always use dark variant
      -gtk-icon-source: -gtk-scaled(url("assets/checkbox#{$as}-dark.png"),
                                    url("assets/checkbox#{$as}-dark@2.png"));
    }

    radio#{$s} {
      -gtk-icon-source: -gtk-scaled(url("assets/radio#{$as}-dark.png"),
                                    url("assets/radio#{$as}-dark@2.png"));
    }
  }

  checkbutton.text-button,
  radiobutton.text-button {
    color: $inverted_secondary_fg_color;
    &:hover,
    &:active,
    &:checked { color: $inverted_fg_color; }
    &:disabled,
    &:disabled:active,
    &:disabled:indeterminate { color: $insensitive_inverted_fg_color; }
  }

  &.csd { // rounded bottom border styling for csd version
    &.background {
      // bigger radius for better antialiasing
      border-bottom-left-radius: 2px;
      border-bottom-right-radius: 2px;
    }
  }

  &.background,
  &.csd.background {
    color: $inverted_secondary_fg_color;
    background-color: $inverted_dark_color;
    opacity: 0.9;

    .dialog-action-area {
      button,
      .linked > button {
        @include button(flat-normal);
        border: 2px solid transparent;
        border-radius: 0;
        color: $inverted_secondary_fg_color;
        font-size: initial;
        font-weight: 700;
        background-size: $text_button_small;
        box-shadow: none;
        // &:first-child { border-bottom-left-radius: 2px; }
        // &:last-child { border-bottom-right-radius: 2px; }

        background-color: transparent;
        color: $secondary_accent_color;
        &:hover {
          @include button(flat-hover);
          color: $accent_color;
        }
        &:active {
          @include button(flat-active);
          color: $accent_color;
        }
        &:checked {
          @include button(flat-checked);
          color: $secondary_accent_color;
        }
        &:disabled { @include button(flat-insensitive); }

        &:first-child {
          border-radius: 0 0 0 2px;
          border-right-width: 0;
        }
        &:last-child {
          border-radius: 0 0 2px 0;
          border-left-width: 0;
        }
      }
    }
  }
}

filechooser {
  .dialog-action-box { border-top: 1px solid $borders_color; }

  #pathbarbox { border-bottom: 1px solid $bg_color; }
}

filechooserbutton:drop(active) {
  box-shadow: none;
  border-color: transparent;
}


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

.sidebar {
  border: none;
  color: $secondary_fg_color;

  &, list { // draw shadows
     &:dir(ltr) { box-shadow: if($variant == 'light', $sidebar-light-ltr,
                                                      $sidebar-dark-ltr);
    }
    &:dir(rtl) { box-shadow: if($variant == 'light', $sidebar-light-rtl,
                                                     $sidebar-dark-rtl);
    }
  }

  // remove background from child-elements
  treeview.view,
  .frame,
  list { background-color: transparent; }

  treeview.view {
    box-shadow: none;
    &:selected,
    row:selected { @extend %selected_items; }
  }

  // fill actual background
  background-color: $secondary_dark_color;
  .frame list { box-shadow: none; }

  list,
  row,
  row.activatable {
    color: $secondary_fg_color;
    background-color: transparent;
    font-weight: 500;
    &:hover { color: $fg_color; }
    &:selected {
      color: $selected_bg_color;
      background-color: transparent;

      label { color: $selected_bg_color; }
    }
  }

  // disable shadows on overshoot/undershoot area
  // of gtk3-demo's sidebar
  overshoot,
  undershoot { box-shadow: none; }
}

stacksidebar {
  row,
  row.activatable {
    padding: rem(5.3px) rem(8px) rem(6.7px);

    > label {
      padding-left: rem(5.3px);
      padding-right: rem(5.3px);
    }

    color: $secondary_fg_color;
    background-color: transparent;
    font-weight: 500;
    &:hover { color: $fg_color; }
    &:selected {
      color: $selected_bg_color;
      background-color: transparent;

      label { color: $selected_bg_color; }
    }
    &:backdrop { opacity: 1.0; }

    &.needs-attention > label { @extend %needs_attention; }
  }

  .frame list { // draw shadows
    // dim background with alpha-blending
    background-color: if($variant == 'light', rgba(12, 18, 0, 0.01),
                                              rgba(18, 22, 0, 0.04));

    &:dir(ltr) { box-shadow: if($variant == 'light', $sidebar-light-ltr,
                                                     $sidebar-dark-ltr);
    }
    &:dir(rtl) { box-shadow: if($variant == 'light', $sidebar-light-rtl,
                                                     $sidebar-dark-rtl);
    }
  }

  // remove unwanted separator
  separator,
  .separator {
    @extend separator.wide;
    min-height: 0;
    border-color: transparent;
    background-color: transparent;
    color: transparent;
  }
}


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

placessidebar {
  @extend scrolledwindow; // needs for overshoot / undershoot

  list,
  row {
    // Background color for Nautilus and FileChooser sidebar
    background-color: $secondary_dark_color;
  }

  row {
    // Needs overriding of the GtkListBoxRow padding
    padding: rem(5.3px) 0 rem(6.7px);

    // Using margins/padding directly in the row
    // will make the animation of the new bookmark row jump
    & > revealer {
      padding: rem(4px) rem(14px) rem(4px) rem(12px);
    }

    & image.sidebar-icon {
      opacity: 0.75; // dim the device icons
      &:dir(ltr) { padding-right: rem(6.7px); }
      &:dir(rtl) { padding-left: rem(6.7px); }
    }

    & label.sidebar-label {
      &:dir(ltr) { padding-right: rem(2px); }
      &:dir(rtl) { padding-left: rem(2px); }
    }

    button {
      &.image-button { // Eject button for removable storages
        padding: rem(6.7px); // Same as of placessidebar row
        @extend button.flat;
      }
    }

    &:selected {
      color: $selected_bg_color;

      label { color: $selected_bg_color; }

      button.image-button {
        color: $secondary_selected_bg_color;
        &:hover,
        &:active { color: $selected_bg_color; }
      }
    }

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

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

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

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

    &:drop(active):not(:disabled) {
      color: $drop_target_color;
      box-shadow: inset 0 1px $drop_target_color,
                  inset 0 -1px $drop_target_color;

      &:selected {
        color: $selected_fg_color;
        background-color: $drop_target_color;
      }
    }
  }
}

placesview {
  .server-list-button > image {
  }

  .server-list-button:checked > image {
  }

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

  // this selects the "connect to server" label
  > actionbar > revealer > box > label {
    padding-left: rem(8px);
    padding-right: rem(8px);
  }
}


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

paned {
  > separator {
    min-width: 1px;
    min-height: 1px;
    border-style: none;
    background-color: transparent;
    -gtk-icon-source: none; // defeats the ugly default handle decoration
    // using background instead of a border
    // since the border will get rendered twice (?)
    background-image: image($borders_color);
    background-size: $separator_narrow;
    transition: none;

    &:backdrop,
    &:selected { // FIXME: is this needed?
      background-image: image($solid_light_borders_color);
      transition: none;
    }

    window & {
      // do not across over GtkHeaderBar with solid border
      &,
      &:backdrop,
      &:selected {
        // FIXME: still happaned double-border though
        background-image: image($paned_borders_color);
        transition: none;
      }
    }

    window > grid.vertical & { // do not use transparentize
      &,
      &:backdrop,
      &:selected {
        background-image: image($solid_light_borders_color);
        transition: none;
      }
    }

    &.wide {
      min-width: rem(6px);
      min-height: rem(6px);
      margin: 0;
      padding: 0;
      // FIXME: use opaque borders to avoid double-border
      background-color: $bg_color;
      background-image: image($solid_light_borders_color),
                        image($solid_light_borders_color);
      background-size: $separator_wide;

      &:backdrop,
      &:selected { // FIXME: is this needed?
        // background-image: none;
        background-image: image($solid_light_borders_color),
                          image($solid_light_borders_color);
      }
    }
  }

  &.horizontal > separator {
    background-repeat: repeat-y;

    &:dir(ltr) {
      margin: 0 rem(-8px) 0 0;
      padding: 0 rem(8px) 0 0;
    }
    &:dir(rtl) {
      margin: 0 0 0 rem(-8px);
      padding: 0 0 0 rem(8px);
    }

    &.wide {
      background-repeat: repeat-y, repeat-y;
      background-position: left, right;
    }
  }

  &.vertical > separator {
    margin: 0 0 rem(-8px) 0;
    padding: 0 0 rem(8px) 0;
    background-repeat: repeat-x;
    background-position: top;

    &.wide {
      background-repeat: repeat-x, repeat-x;
      background-position: bottom, top;
    }
  }
}


/**************
 * GtkInfoBar *
 **************/

infobar {
  padding: rem(5.3px);
  border-width: 0 0 1px;
  border-style: solid;
  // do not use transparentize
  border-color: $solid_light_borders_color;
  background-color: $secondary_dark_color;
}

.info,
.question,
.warning,
.error {
  // always use dark forefground
  &:not(.error) {
    color: if($variant == 'light', $secondary_fg_color,
                                   $secondary_fixed_fg_color);
  }

  button {
    @include button(flat-normal);
    color: $secondary_fixed_fg_color;
    &:hover {
      @include button(flat-hover);
      color: $fixed_fg_color;
    }
    &:active {
      @include button(flat-active);
      color: $fixed_fg_color;
    }
    &:checked {
      @include button(flat-checked);
      color: $fixed_fg_color;
    }
    &:disabled { color: $insensitive_fixed_fg_color; }
    &.flat {
      color: $secondary_fixed_fg_color;
      &:hover, &:active { color: $fixed_fg_color; }
      &:disabled { color: $insensitive_fixed_fg_color; }
    }

    &.image-button {
      min-height: rem(13.3px);
      min-width: rem(13.3px);
      padding: rem(6.7px) rem(2.7px) rem(6.7px);
      border-radius: 100px;
      -gtk-outline-radius: 100px;
    }
  }

  selection { background-color: darken($selected_bg_color, 10%); }

  progressbar { // use 'white' bit and trough
    trough { background-color: gtkopacity($selected_fg_color, 0.2); }
    progress { background-color: $selected_fg_color; }
  }
}

.info { background-color: $info_bg_color; }

.question { background-color: $question_bg_color; }

.warning { background-color: $warning_bg_color; }

.error { // use white test for this
  color: $selected_fg_color;
  background-color: $error_bg_color;
}


/************
 * 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.
    border: 1px solid gtkopacity($inverted_dark_color, 0.9);
    background-color: gtkopacity($inverted_dark_color, 0.9);
    background-clip: padding-box;
  }

  color: $inverted_fg_color;
  padding: rem(4px);
  border-radius: 2px;
  box-shadow: none; // otherwise it gets inherited by windowframe.csd

  // FIXME: we need a border or tooltips vanish on black background.
  decoration { background-color: transparent; }

  * { // Yeah this is ugly
    background-color: transparent;
    color: $inverted_fg_color;
  }
}


/*****************
 * 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 {}, colorswatch has the programmatically set
  // background, so most of the style is applied to the overlay box.

  box-shadow: $z-depth-1;

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

  // 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 colorswatch > .overlay and colorswatch.overlay,
  // I know it's weird, but this is gtk+, not a browser.
  &.top {
    border-top-left-radius: 2px;
    border-top-right-radius: 2px;
  }
  &.bottom {
    border-bottom-left-radius: 2px;
    border-bottom-right-radius: 2px;
  }
  &.left, &:first-child:not(.overlay):not(.top) {
    border-top-left-radius: 2px;
    border-bottom-left-radius: 2px;
  }
  &.right, &:last-child:not(.overlay):not(.bottom) {
    border-top-right-radius: 2px;
    border-bottom-right-radius: 2px;
  }
  &:only-child:not(.overlay) { border-radius: 2px; }

  // overlay corner rounding
  &.top > .overlay {
    border-top-left-radius: 2px;
    border-top-right-radius: 2px;
  }
  &.bottom > .overlay {
    border-bottom-left-radius: 2px;
    border-bottom-right-radius: 2px;
  }
  &:first-child:not(.top) > .overlay {
    border-top-left-radius: 2px;
    border-bottom-left-radius: 2px;
  }
  &:last-child:not(.bottom) > .overlay {
    border-top-right-radius: 2px;
    border-bottom-right-radius: 2px;
  }
  &:only-child > .overlay { border-radius: 2px; }

  // hover effect
  &:hover { box-shadow: $z-depth-2; }

  // no hover effect for the colorswatch in the color editor
  GtkColorEditor & {
    border-radius: 2px; // same radius as the entry
    &:hover { box-shadow: $z-depth-1; }
  }

  // indicator and keynav outline colors
  &.color-dark {
    color: white;
  }
  &.color-light {
    color: gtkopacity(black, 0.8);
  }

  // border color
  &.overlay,
  &.overlay:selected {
  }

  // make the add color button looks like, well, a button
  &#add-color-button {
  background-image: linear-gradient(to right,
                                    $error_bg_color 25%,
                                    $warning_bg_color 25%, $warning_bg_color 50%,
                                    $info_bg_color 50%, $info_bg_color 75%,
                                    $question_bg_color 75%);
  color: white;
  }
}

// colorscale popup
colorchooser .popover.osd {
  padding: 3px;
  border-style: solid;
  border-width: 9px;
  border-radius: 2px;
  border-image: -gtk-scaled(url("assets/osd-shadow#{$asset_suffix}.png"),
                            url("assets/osd-shadow#{$asset_suffix}@2.png"))
                10 / 10px stretch;
  box-shadow: none;
  color: $inverted_fg_color;
  background-color: $inverted_dark_color;
  &:backdrop {
    border-image: -gtk-scaled(url("assets/osd-shadow-backdrop#{$asset_suffix}.png"),
                              url("assets/osd-shadow-backdrop#{$asset_suffix}@2.png"))
                  10 / 10px stretch;
  }

  label {
    color: $accent_color;
    font-weight: 700;
  }
}


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

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

@keyframes volume_hover {
  from {
    background-image: -gtk-gradient(radial,
                                    center center, 0,
                                    center center, 0.001,
                                    to(gtkalpha(currentColor, 0)),
                                    to(transparent));
  }
  to {
    background-image: -gtk-gradient(radial,
                                    center center, 0,
                                    center center, 0.5,
                                    to(gtkalpha(currentColor, 0.1)),
                                    to(transparent));
  }
}

.scale-popup {
   .osd & { @extend %osd; }

   .osd & button.flat { // FIXME: quick hack, redo properly
   }

  .osd & .vertical button,
  & .vertical button { // +/- buttons on GtkVolumeButton popup
    // padding: rem(10.7px);
    border-radius: 100px;
    -gtk-outline-radius: 100px;
    background-color: transparent;
    color: $secondary_fg_color;

    &:first-child { // '+' button
      &:hover {
        @include button(flat-hover);
        background: none;
        color: $success_color;
        animation: volume_hover 0.2s linear forwards;
      }
      &:disabled {
        @include button(flat-insensitive);
        background: none;
        color: gtkalpha($success_color, 0.4);
      }
    }
    &:last-child { // '-' button
      &:hover {
        @include button(flat-hover);
        background: none;
        color: $error_color;
        animation: volume_hover 0.2s linear forwards;
      }
      &:disabled {
        @include button(flat-insensitive);
        background: none;
        color: gtkalpha($error_color, 0.4);
      }
    }
  }
  .osd & button,
  button {
    border-radius: 100px;
    -gtk-outline-radius: 100px;
    background-color: transparent;
    color: $secondary_fg_color;

    &:first-child { // '-' button
      &:hover {
        @include button(flat-hover);
        background: none;
        color: $error_color;
        animation: spin_hover 0.2s linear forwards;
      }
      &:disabled {
        @include button(flat-insensitive);
        background: none;
        color: gtkalpha($error_color, 0.4);
      }
    }
    &:last-child { // '+' button
      &:hover {
        @include button(flat-hover);
        background: none;
        color: $success_color;
        animation: spin_hover 0.2s linear forwards;
      }
      &:disabled {
        @include button(flat-insensitive);
        background: none;
        color: gtkalpha($success_color, 0.4);
      }
    }
  }
}

button.flat.scale { // standalone Speaker/Mic buttons
  // 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;
  min-width: rem(17.3px);
  min-height: rem(17.3px);
  padding: rem(10px);
  border-radius: 100px;
  -gtk-outline-radius: 100px;
}

.nautilus-window .floating-bar {
  @extend %osd;
  // @extend toolbar.osd;
  padding: rem(1.3px) 0 rem(2.7px);
  border: 1px solid transparent;
  border-radius: 0;
  color: $inverted_secondary_fg_color;
  background-color: $inverted_dark_color;
  transition: none;

  button {
    min-height: rem(13.3px);
    min-width: rem(13.3px);
    padding: rem(4px);
    margin: 0 rem(4px);
    color: $secondary_accent_color;
    &:hover,
    &:active,
    &:checked { color: $accent_color; }
    &:disabled { color: gtkopacity($accent_color, 0.4); }
  }

  spinner {
    min-height: rem(12px);
    min-width: rem(12px);
    padding: rem(6.7px) 0 rem(6.7px);
    margin: 0 rem(-1px);
  }
}

// axes left border and border radius
.nautilus-window .floating-bar.bottom.left {
  border-width: 1px 1px 0 0;
  border-radius: 0 2px + 1px 0 0;
  // border-width: 8px 8px 0 0;
  // border-image-width: 10px 10px 0 0;
}

// axes right border and border radius
.nautilus-window .floating-bar.bottom.right {
  border-width: 1px 0 0 1px;
  border-radius: 2px + 1px 0 0 0;
  // border-width: 8px 0 0 8px;
  // border-image-width: 10px 0 0 10px;
}


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

decoration {
  transition: none;
  border-radius: 2px 2px 0 0;
  // lamefun trick to get rounded borders regardless of CSD use
  border-width: 0;
  box-shadow: $z-depth-4;

  // FIXME rationalize shadows

  // this is used for the resize cursor area
  margin: 8px;

  &:backdrop {
    // the transparent shadow here is to enforce that the shadow extents don't
    // change when we go to backdrop, to prevent jumping windows.
    // The biggest shadow should be in the same order then in the active state
    // or the jumping will happen during the transition.
    box-shadow: $z-depth-2-backdrop;
    transition: none;
  }

  .fullscreen &,
  .maximized &,
  .tiled & {
    border-radius: 0;
    transition: none;
  }

  .popup & { box-shadow: none; }

  // server-side decorations as used by mutter
  .ssd & {
    button {
      @extend button.flat;
      border-radius: 100px;
      -gtk-outline-radius: 100px;
    }

    // just doing borders, wm draws actual shadows
    // otherwise incorrect shadows are appeared
    box-shadow: $z-depth-1-backdrop;

    .tiled & .titlebar {
      @extend %tiled_integration;
      transition: none;
    }
    .maximized & .titlebar {
      @extend %maxd_integration;
      transition: none;
    }
  }

  .csd.popup & {
    border-radius: 2px;
    box-shadow: $z-depth-3;
  }
  tooltip.csd & {
    border-radius: 2px;
    box-shadow: $z-depth-2;
  }
  message-dialog.csd & {
    border-radius: 2px;
    box-shadow: $z-depth-4;
    &:backdrop {
      box-shadow: $z-depth-2-backdrop;
      transition: none;
    }
  }

  .solid-csd & {
    border-radius: 2px 2px 0 0;
    margin: -1px;
    background-color: $bg_color;
    border: none;
    box-shadow: none;
  }
}

// Window manager buttons
.csd headerbar,
.csd .titlebar {
  button.titlebutton,
  &.selection-mode button.titlebutton {
    @extend %fade_effect;
    @extend button.flat;
    min-width: rem(13.3px);
    min-height: rem(13.3px);
    padding: rem(10px);
    border-radius: 100px;
    -gtk-outline-radius: 100px;
    

    &.close,
    &.minimize,
    &.maximize {
      &:hover:backdrop,
      &:active:backdrop { opacity: 1.0; }

      > image {
        min-height: 16px;
	min-width: 16px;
        color: transparent;
        background-size: 16px 16px;
        background-repeat: no-repeat;
        background-position: center;
      }
    }

    // raised 'Close' button
    &.close {
      > image {
        background-image: -gtk-scaled(url("assets/window-close.png"),
                                      url("assets/window-close@2.png"));
      }

      &:hover {
        @include button(hover);
        color: $selected_fg_color;
        background-color: $destructive_color;

        > image {
          background-image: -gtk-scaled(url("assets/window-close-active.png"),
                                        url("assets/window-close-active@2.png"));
        }
      }
      &:active {
        @include button(active);
        color: $selected_fg_color;
        background-color: $selected_bg_color;

        > image {
          background-image: -gtk-scaled(url("assets/window-close-active.png"),
                                        url("assets/window-close-active@2.png"));
        }
      }
    }

    &.minimize {
      > image {
        background-image: -gtk-scaled(url("assets/window-minimize.png"),
                                      url("assets/window-minimize@2.png"));
      }

      &:hover,
      &:active {
        > image {
          background-image: -gtk-scaled(url("assets/window-minimize-active.png"),
                                        url("assets/window-minimize-active@2.png"));
        }
      }
    }

    &.maximize {
      > image {
        background-image: -gtk-scaled(url("assets/window-maximize.png"),
                                      url("assets/window-maximize@2.png"));
      }

      &:hover,
      &:active {
        > image {
          background-image: -gtk-scaled(url("assets/window-maximize-active.png"),
                                        url("assets/window-maximize-active@2.png"));
        }
      }
    }
  }
}

.csd.maximized headerbar,
.csd.maximized .titlebar {
  & button.titlebutton,
  &.selection-mode button.titlebutton {
    &.maximize {
      > image {
        background-image: -gtk-scaled(url("assets/window-unmaximize.png"),
                                      url("assets/window-unmaximize@2.png"));
      }

      &:hover,
      &:active {
        > image {
          background-image: -gtk-scaled(url("assets/window-unmaximize-active.png"),
                                        url("assets/window-unmaximize-active@2.png"));
        }
      }
    }
  }
}

// specific button styling for SSDs
.ssd .titlebar {
  button.titlebutton {
    &.close,
    &.minimize,
    &.maximize { // reset styling
      color: transparent;
      background-size: 28px 28px;
      background-repeat: no-repeat;
      background-position: center;
      background: none;
      box-shadow: none;
      &:backdrop,
      &:hover:backdrop,
      &:active:backdrop { color: transparent; }
    }

    @each $_class,
          $_state,
          $_shadow in ('', '', none),
                      (':hover', '-hover', $z-depth-2),
                      (':active', '-active', $z-depth-2),
                      (':backdrop', '-backdrop', none),
                      (':backdrop:hover', '-backdrop-hover', $z-depth-2),
                      (':backdrop:active', '-backdrop-active', $z-depth-2) {
      &.close#{$_class} {
        background-image: -gtk-scaled(
                          url("assets/window-close-ssd#{$_state}.png"),
                          url("assets/window-close-ssd#{$_state}@2.png"));
        box-shadow: #{$_shadow};
      }
    }

    @each $_class, $_state in ('', ''),
                              (':hover', '-hover'),
                              (':active', '-active'),
                              (':backdrop', '-backdrop'),
                              (':backdrop:hover', '-backdrop-hover'),
                              (':backdrop:active', '-backdrop-active') {
      &.minimize#{$_class} {
        background-image: -gtk-scaled(
                          url("assets/window-minimize-ssd#{$_state}.png"),
                          url("assets/window-minimize-ssd#{$_state}@2.png"));
      }
    }

    @each $_class, $_state in ('', ''),
                              (':hover', '-hover'),
                              (':active', '-active'),
                              (':backdrop', '-backdrop'),
                              (':backdrop:hover', '-backdrop-hover'),
                              (':backdrop:active', '-backdrop-active') {
      &.maximize#{$_class} {
        background-image: -gtk-scaled(
                          url("assets/window-maximize-ssd#{$_state}.png"),
                          url("assets/window-maximize-ssd#{$_state}@2.png"));
      }
    }
  }
}

.maximized.ssd .titlebar {
  button.titlebutton {
    @each $_class, $_state in ('', ''),
                              (':hover', '-hover'),
                              (':active', '-active'),
                              (':backdrop', '-backdrop'),
                              (':backdrop:hover', '-backdrop-hover'),
                              (':backdrop:active', '-backdrop-active') {
      &.maximize#{$_class} {
        background-image: -gtk-scaled(
                          url("assets/window-unmaximize-ssd#{$_state}.png"),
                          url("assets/window-unmaximize-ssd#{$_state}@2.png"));
      }
    }
  }
}

.ssd decoration .titlebar {
  // shrink titlebar height for SSD
  button.titlebutton {
    min-width: 26.7px;
    min-height: 26.7px;
    padding: 0;
  }
}

// catch all extend :)
%selected_items {
  background-color: $selected_bg_color;

  @at-root %nobg_selected_items, & {
    color: $selected_fg_color;
    &:disabled { color: $insensitive_selected_fg_color; }
    &:backdrop {
      // color: $backdrop_selected_fg_color;
      &:disabled { color: $insensitive_selected_fg_color; }
    }
  }
}

.monospace { font-family: Monospace; }


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

// touch selection handlebars for the Popover.osd above
cursor-handle {
  background-color: $success_color;
  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;
}

popover.touch-selection {
  font: initial;
  color: $fg_color;
  background-color: $base_color;
  box-shadow: $z-depth-2;
  &:backdrop { box-shadow: $z-depth-1; }
  button {
  }
}

button.circular {
  border-radius: 100px;
  -gtk-outline-radius: 100px;

  label { padding: 0; }
}

// shortcut window keys
.keycap {
  min-width: rem(20px);
  min-height: rem(26px);
  margin-top: rem(2.7px);
  margin-bottom: rem(3.3px);
  padding: 0 rem(6px);
  border: none;
  border-radius: 2px;
  color: $fg_color;
  background-color: $base_color;
  box-shadow: $z-depth-1;
  font-size: 90%;
  font-weight: 500;
}

// FIXME: needs to be done widget by widget,
// this wildcard should really die
*:drop(active):focus,
*:drop(active) {
  border-color: $drop_target_color;
  box-shadow: inset 0 0 0 1px $drop_target_color;
  caret-color: $drop_target_color;
}

// FIXME: aggregate with buttons
stackswitcher button.circular,
stackswitcher button.text-button.circular {
  min-width: rem(37.3px);
  min-height: rem(37.3px);
  padding: 0;
}

// undershoot for speciic-cases
undershoot {
  box > scrolledwindow & {
    &.top { @include undershoot(top, $bg_color); }
    &.bottom { @include undershoot(bottom, $bg_color); }
    &.left { @include undershoot(left, $bg_color); }
    &.right { @include undershoot(right, $bg_color); }
  }

  placessidebar &,
  .sidebar & {
    &.top { @include undershoot(top, $secondary_dark_color); }
    &.bottom { @include undershoot(bottom, $secondary_dark_color); }
    &.left { @include undershoot(left, $secondary_dark_color); }
    &.right { @include undershoot(right, $secondary_dark_color); }
  }
}