gtk2/gtk/gtk-default.css

@define-color fg_color #000;
@define-color bg_color #dcdad5;
@define-color text_color #000;
@define-color base_color #fff;
@define-color selected_bg_color #4b6983;
@define-color selected_fg_color #fff;
@define-color tooltip_bg_color #eee1b3;
@define-color tooltip_fg_color #000;
@define-color placeholder_text_color #808080;

@define-color info_fg_color rgb (181, 171, 156);
@define-color info_bg_color rgb (252, 252, 189);
@define-color warning_fg_color rgb (173, 120, 41);
@define-color warning_bg_color rgb (250, 173, 61);
@define-color question_fg_color rgb (97, 122, 214);
@define-color question_bg_color rgb (138, 173, 212);
@define-color error_fg_color rgb (166, 38, 38);
@define-color error_bg_color rgb (237, 54, 54);

@define-color success_bg_color #4e9a06;

* {
  color: @fg_color;
  border-color: shade (@bg_color, 0.6);
  padding: 2px;
}

GtkWindow, .button, .slider {
  background-color: @bg_color;
}

.expander, GtkTreeView.view.expander {
  color: #fff;
}

.expander:hover,
GtkTreeView.view.expander:selected:hover {
  color: @text_color;
}

*:insensitive {
  border-color: shade (@bg_color, 0.7);
  background-color: shade (@bg_color, 0.9);
  color: shade (@bg_color, 0.7);
}

.entry:selected {
  background-color: shade (@bg_color, 0.9);
  color: @fg_color;
}

.entry:selected:focused {
  background-color: @selected_bg_color;
  color: @selected_fg_color;
}

.view {
  border-width: 0;
  border-radius: 0;
  background-color: @base_color;
  color: @text_color;
}
.view:selected {
  background-color: shade (@bg_color, 0.9);
  color: @fg_color;
}

.view:selected:focused {
  background-color: @selected_bg_color;
  color: @selected_fg_color;
}

.view column:sorted row,
.view column:sorted row:hover {
  background-color: shade (@bg_color, 0.85);
}

.view column:sorted row:nth-child(odd),
.view column:sorted row:nth-child(odd):hover {
  background-color: shade (@bg_color, 0.8);
}

.view row,
.view row:hover {
  background-color: @base_color;
  color: @text_color;
}

.view row:nth-child(odd),
.view row:nth-child(odd):hover {
  background-color: shade (@base_color, 0.93);
}

.view row:selected:focused {
  background-color: @selected_bg_color;
}

.view row:selected {
  background-color: darker (@bg_color);
  color: @selected_fg_color;
}

.view.cell.trough,
.view.cell.trough:hover,
.view.cell.trough:selected,
.view.cell.trough:selected:focused {
  background-color: @bg_color;
  color: @fg_color;
}

.view.cell.progressbar,
.view.cell.progressbar:hover,
.view.cell.progressbar:selected,
.view.cell.progressbar:selected:focused {
  background-color: @selected_bg_color;
  color: @selected_fg_color;
}

.rubberband {
  background-color: alpha (@fg_color, 0.25);
  border-color: @fg_color;
  border-style: solid;
  border-width: 1px;
}

.tooltip,
.tooltip * {
  background-color: @tooltip_bg_color;
  color: @tooltip_fg_color;
  border-color: @tooltip_fg_color;
  border-width: 1px;
  border-style: solid;
}

.button,
.slider {
  border-style: outset;
  border-width: 2px;
}

.button:active {
  background-color: shade (@bg_color, 0.7);
  border-style: inset;
}

.spinbutton.button:hover,
.button:hover,
.slider:hover {
  background-color: @selected_bg_color;
  color: @selected_fg_color;
  border-color: shade (@selected_bg_color, 0.7);
}

.trough {
  background-color: darker (@bg_color);
  border-style: inset;
  border-width: 1px;
  padding: 0;
}

.entry {
  border-style: inset;
  border-width: 2px;
  background-color: @base_color;
  color: @text_color;
}

.entry:insensitive {
  background-color: shade (@base_color, 0.9);
  color: shade (@base_color, 0.7);
}
.entry:active {
  background-color: #c4c2bd;
  color: #000;
}

.progressbar,
.entry.progressbar,
.cell.progressbar {
  background-color: @selected_bg_color;
  border-color: shade (@selected_bg_color, 0.7);
  color: @selected_fg_color;
  border-style: outset;
  border-width: 1px;
}

.level-bar.indicator-discrete {
    margin: 1px;
}

.level-bar.fill-block {
    background-color: @selected_bg_color;
}

.level-bar.fill-block.level-low {
    background-color: @warning_bg_color;
}

.level-bar.fill-block.level-high {
    background-color: @success_bg_color;
}

.level-bar.fill-block.empty-fill-block {
    background-color: @base_color;
}

GtkCheckButton:hover,
GtkCheckButton:selected,
GtkRadioButton:hover,
GtkRadioButton:selected {
  background-color: shade (@bg_color, 1.05);
}

.check, .radio,
.cell.check, .cell.radio,
.cell.check:hover, .cell.radio:hover {
  border-style: solid;
  border-width: 1px;
  background-color: @base_color;
  border-color: @fg_color;
}

.check:active, .radio:active,
.check:hover, .radio:hover {
  background-color: @base_color;
  border-color: @fg_color;
  color: @text_color;
}

.check:selected, .radio:selected {
  background-color: darker (@bg_color);
  color: @selected_fg_color;
  border-color: @selected_fg_color;
}

.check:selected:focused, .radio:selected:focused {
  background-color: @selected_bg_color;
}

.menuitem.check, .menuitem.radio {
  color: @fg_color;
  border-style: none;
  border-width: 0;
}

.popup {
  border-style: outset;
  border-width: 1px;
}

.viewport {
  border-style: inset;
  border-width: 2px;
}

.notebook {
  border-style: outset;
  border-width: 1px;
}

.frame {
  border-style: inset;
  border-width: 1px;
}

GtkScrolledWindow.frame {
  padding: 0;
}

.menu,
.menubar,
.toolbar {
  border-style: outset;
  border-width: 1px;
}

.menu:hover,
.menubar:hover,
.menuitem:hover,
.menuitem.check:hover,
.menuitem.radio:hover {
  background-color: @selected_bg_color;
  color: @selected_fg_color;
}

GtkSpinButton.button {
  border-width: 1px;
}

.scale.slider:hover,
GtkSpinButton.button:hover {
  background-color: shade (@bg_color, 1.05);
  border-color: shade (@bg_color, 0.8);
}

GtkSwitch.trough:active {
  background-color: @selected_bg_color;
  color: @selected_fg_color;
}

GtkToggleButton.button:inconsistent {
  border-style: outset;
  border-width: 1px;
  background-color: shade (@bg_color, 0.9);
  border-color: shade (@bg_color, 0.7);
}

GtkLabel:selected {
  background-color: shade (@bg_color, 0.9);
}

GtkLabel:selected:focused {
  background-color: @selected_bg_color;
}

.info {
  background-color: @info_bg_color;
  color: @info_fg_color;
}

.warning {
  background-color: @warning_bg_color;
  color: @warning_fg_color;
}

.question {
  background-color: @question_bg_color;
  color: @question_fg_color;
}

.error {
  background-color: @error_bg_color;
  color: @error_fg_color;
}

.highlight {
  background-color: @selected_bg_color;
  color: @selected_fg_color;
}

.light-area-focus {
  color: #000;
}

.dark-area-focus {
  color: #fff;
}
GtkCalendar.view {
  border-width: 1px;
  border-style: inset;
  padding: 1px;
}

GtkCalendar.view:inconsistent {
  color: darker (@bg_color);
}

GtkCalendar.header {
  background-color: @bg_color;
  border-style: outset;
  border-width: 2px;
}

GtkCalendar.highlight {
  border-width: 0;
}

GtkCalendar.button {
  background-color: @bg_color;
}

GtkCalendar.button:hover {
  background-color: lighter (@bg_color);
  color: @fg_color;
}

.menu * {
  border-width: 0;
  padding: 2px;
}