one-dark/gtk-3.0/sass/ui/dialog.scss

//
// Dialogs
//
.dialog-action-area .button.text-button {
  padding: 6px 16px;
}

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

.message-dialog {
  // Message Dialog styling
  -GtkDialog-button-spacing: 0;

  .titlebar {
    background-color: $header_bg;
    border-bottom: 1px solid darken($header_bg, 7%);
  }

  &.csd {
    // rounded bottom border styling for csd version
    &.background {
      border-bottom-left-radius: 3px;
      border-bottom-right-radius: 3px;
      border: none;
    }
    .dialog-action-area .button {
      padding: 8px;
      border-radius: 0;

      @extend %middle_button;

      &:hover,
      &:active,
      &:disabled {
        @extend %middle_button;
      }

      &:first-child {
        @extend %first_button;
      }
      &:last-child {
        @extend %last_button;
      }
    }
    %middle_button {
      border-right-style: none;
      border-bottom-style: none;
    }
    %last_button {
      border-bottom-right-radius: 3px;
    }
    %first_button {
      border-left-style: none;
      border-bottom-left-radius: 3px;
    }
  }
}


//
// FileChooser
//
filechooser {
  #pathbarbox {
    background-color: $filechooser_bg;
    border-bottom: 1px solid $borders_color;
  }

  .search-bar {
    background-color: $filechooser_bg;
  }

  actionbar {
    background-color: $bg_color;
  }
}

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






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

  &.info,
  &.question,
  &.warning,
  &.error {
    background-color: $selected_bg_color;
    color: $selected_fg_color;
    caret-color: currentColor;

    button {
      @extend %selected_button;
    }

    selection {
      color: $selected_bg_color;
      background-color: $selected_fg_color;
    }

    *:link {
      @extend %link_selected;
    }

    &:disabled {
      label,
      image {
        color: transparentize($selected_fg_color, 0.5);
      }
    }
  }

  &.warning {
    background-color: $warning_color;
  }
  &.error {
    background-color: $destructive_color;
  }
  &.question {
    background-color: $question_color;
  }
}









//
// Tooltips
//
tooltip,
.tooltip {
  &.background {
    // background-color needs to be set this way otherwise it gets drawn twice
    // see https://bugzilla.gnome.org/show_bug.cgi?id=736155 for details.
    background-color: $tooltip_bg_color;
    background-clip: padding-box;

    label {
      padding: 4px;
    }
  }

  color: $tooltip_fg_color;
  border-radius: 2px;
  border: 1px solid $tooltip_border_color;

  decoration {
    background-color: transparent;
  }

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