chromium/ui/file_manager/file_manager/foreground/css/combobutton.css

/* Copyright 2023 The Chromium Authors
 * Use of this source code is governed by a BSD-style license that can be
 * found in the LICENSE file. */

.dialog-header button.combobutton {
  align-items: stretch;
  background: transparent;
  border-radius: 3px;
  cursor: pointer;
  display: flex;
  flex: none;
  font-weight: 500;
  outline: none;
  padding: 8px;
  position: relative;
  user-select: none;
}

.dialog-header .combobutton > .button {
  align-items: center;
  display: flex;
}

.dialog-header .combobutton > .button > .action {
  background-position: left center;
  background-repeat: no-repeat;
  background-size: 16px 16px;
  padding-top: 1px;
  z-index: 1;
}

html[dir='rtl'] .dialog-header .combobutton > .button > .action {
  background-position: right center;
}

.dialog-header .combobutton > .button > .trigger {
  align-items: center;
  display: inline-flex;
  height: 20px;
  justify-content: center;
  margin-inline-start: 8px;
  width: 20px;
}

/* This pseudo element expands clickable area of the .trigger */
.dialog-header .combobutton > .button > .trigger::before {
  content: '';
  display: block;
  height: 48px;
  position: absolute;
  right: 12px; /* Same value as padding-inline-end of the button. */
  width: 20px;
}

.dialog-header .combobutton:not([multiple]) > .button > .trigger {
  display: none;
}

.dialog-header .combobutton[hidden] {
  display: none;
}