gecko-dev/toolkit/components/prompts/content/selectDialog.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 {
  min-width: 29em;
}

#selectContainer {
  max-width: 45em;
  margin: 5px;
}