gecko-dev/browser/extensions/formautofill/content/editProfile.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/. */

body {
  font-size: 1rem;
  /* body needs padding until the edit profile dialog could be loaded as a
     stacked subdialog */
  padding: 2em;
}

form,
label,
div {
  display: flex;
}

form {
  flex-wrap: wrap;
}

label {
  margin: 0 0 0.5em;
}

label > span {
  flex: 0 0 8em;
  padding-inline-end: 0.5em;
  align-self: center;
  text-align: end;
}

input,
select {
  flex: 1 0 auto;
  width: 9em;
}

option {
  padding: 6px;
}

textarea {
  resize: none;
}

button {
  padding: 3px 2em;
}

#country-container {
  width: 15em;
}

#first-name-container,
#middle-name-container,
#address-level1-container,
#postal-code-container,
#country-container {
  flex: 0 1 50%;
}

#last-name-container,
#organization-container,
#street-address-container,
#address-level2-container,
#email-container,
#tel-container,
#controls-container {
  flex: 0 1 100%;
}

#controls-container {
  justify-content: end;
}

#last-name,
#organization,
#address-level2,
#tel{
  flex: 0 0 auto;
  width: calc(50% - 10em);
}

#street-address,
#email {
  flex: 1 0 auto;
}

#first-name-container,
#middle-name-container,
#last-name-container {
  /* Hide until we support names */
  display: none;
}