gecko-dev/browser/base/content/aboutDialog.css

#aboutDialog {
  padding-top: 0;
  -moz-padding-end: 0;
  padding-bottom: 10px;
  -moz-padding-start: 0;
  width: 600px;
}

#clientBox {
  background-color: #F7F7F7;
  color: #222222;
}

#leftBox {
  background-image: url("chrome://branding/content/about-logo.png");
  background-repeat: no-repeat;
  /* min-width and min-height create room for the logo */
  min-width: 210px;
  min-height: 210px;
  margin-top:20px;
  -moz-margin-start: 30px;
}

#rightBox {
  background-image: url("chrome://branding/content/about-wordmark.png");
  background-repeat: no-repeat;
  /* padding-top creates room for the wordmark */
  padding-top: 38px;
  margin-top:20px;
  -moz-margin-end: 30px;
  -moz-margin-start: 30px;
}

#rightBox:-moz-locale-dir(rtl) {
  background-position: 100% 0;
}

#bottomBox {
  padding: 15px 10px 0;
}

#version {
  margin-top: 5px;
  -moz-margin-start: 0;
}

#distribution,
#distributionId {
  font-weight: bold;
  display: none;
  margin-top: 0;
  margin-bottom: 0;
}

.text-blurb {
  margin-bottom: 10px;
  -moz-margin-start: 0;
  -moz-padding-start: 0;
}

#updateBox {
  margin-bottom: 10px;
}

#updateButton,
#updateDeck > hbox > label {
  -moz-margin-start: 0;
  -moz-padding-start: 0;
}

#updateDeck > hbox > label:not([class="text-link"]) {
  color: #909090;
  font-style:italic;
}

.update-throbber {
  width: 16px;
  min-height: 16px;
  -moz-margin-end: 3px;
  list-style-image: url("chrome://global/skin/icons/loading_16.png");
}

.trademark-label,
.text-link,
.text-link:focus {
  margin: 0px;
  padding: 0px;
}

.bottom-link,
.bottom-link:focus {
  text-align: center;
  margin: 0 40px;
}

#trademark {
  font-size: xx-small;
  text-align: center;
  color: #999999;
  margin-top: 10px;
}