palemoon-dev/platform/devtools/client/framework/options-panel.css

/* This Source Code Form is subject to the terms of the Mozilla Public
 * License, v. 2.0. If a copy of the MPL was not distributed with this
 * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
:root{
  -moz-user-select: none;
}

#options-panel-container {
  overflow: auto;
}

#options-panel {
  display: block;
}

.options-vertical-pane {
  display: inline;
  float: left;
}

.options-vertical-pane {
  margin: 5px;
  width: calc(100%/3 - 10px);
  min-width: 320px;
  padding-inline-start: 5px;
  box-sizing: border-box;
}

/* Snap to 50% width once there is not room for 3 columns anymore.
   This prevents having 2 columns showing in a row, but taking up
   only ~66% of the available space. */
@media (max-width: 1000px) {
  .options-vertical-pane {
    width: calc(100%/2 - 10px);
  }
}

.options-vertical-pane fieldset {
  border: none;
}

.options-vertical-pane fieldset legend {
  font-size: 1.4rem;
  margin-inline-start: -15px;
  margin-bottom: 3px;
  cursor: default;
}

.options-vertical-pane fieldset + fieldset {
  margin-top: 1rem;
}

.options-groupbox {
  margin-inline-start: 15px;
  padding: 2px;
}

.options-groupbox label {
  display: flex;
  padding: 4px 0;
  align-items: center;
}

/* Add padding for label of select inputs in order to
   align it with surrounding checkboxes */
.options-groupbox label span:first-child {
  padding-inline-start: 5px;
}

.options-groupbox label span + select {
  margin-inline-start: 4px;
}

.options-groupbox.horizontal-options-groupbox label {
  display: inline-flex;
  align-items: flex-end;
}

.options-groupbox.horizontal-options-groupbox label + label {
  margin-inline-start: 4px;
}

.options-groupbox > *,
.options-groupbox > .hidden-labels-box > checkbox {
  padding: 2px;
}

.options-groupbox > .hidden-labels-box {
  padding: 0;
}

.options-citation-label {
  display: inline-block;
  font-size: 1rem;
  font-style: italic;
   /* To align it with the checkbox */
  padding: 4px 0 0;
  padding-inline-end: 4px;
}

#devtools-sourceeditor-keybinding-select {
  min-width: 130px;
}

#devtools-sourceeditor-tabsize-select {
  min-width: 80px;
}