gecko-dev/mobile/themes/core/netError.css

/*
 *  This defines the look-and-feel styling of the error pages.
 *  (see: netError.xhtml)
 *
 *  Original styling by William Price <bugzilla@mob.rice.edu>
 *  Updated for mobile by: Wes Johnston <wjohnston@mozilla.com>
 */

body {
  margin: 0;
  padding: 0 8px 8px;
  font-family: "Nokia Sans", Tahoma, sans-serif !important;
}

h1 {
  font-size: 22px;
}

h2 {
  font-size: 16px;
}

ul {
  margin: 0px;
  padding: 0px 0px 0px 1em;
}

li {
  margin: 0px;
  padding: 8px 0px;
}

#errorPage {
  background-color: #CEE6F4;
}

#errorPage.certerror {
  background-color: #EFD400;
}

#errorPage.blockedsite {
  background-color: #BF0000;
}

#errorTitle {
  background: url("chrome://browser/skin/images/errorpage-warning.png") left center no-repeat;
  /* Scaled by .666 of their actual size */
  background-size: 40px 40px;
  background-origin: content-box;
  min-height: 60px;
  margin-left: auto;
  margin-right: auto;
  max-width: 500px;
  margin-left: auto;
  margin-right: auto;
}

#errorPage.certerror #errorTitle {
  background-image: url("chrome://browser/skin/images/errorpage-larry-black.png");
}

#errorPage.blockedsite #errorTitle {
  background-image: url("chrome://browser/skin/images/errorpage-larry-white.png");
  color: white;
}

.errorTitleText {
  padding: 0px 0px 0px 50px;
  display: inline-block;
  vertical-align: middle
}

#errorPageContainer {
  background-color: white;
  border: 1px solid #999999;
  border-radius: 6px;
  padding: 6px 20px 20px;
  font-size: 14px;
  max-width: 500px;
  margin-left: auto;
  margin-right: auto;
}

#errorShortDesc > p:empty {
  display: none;
}

#errorShortDesc > p {
  overflow: auto;
  border-bottom: 1px solid #999999;
  padding-bottom: 1em;
}

#errorPage.blockedsite #errorShortDesc > p {
  font-weight: bold;
  border-bottom: none;
  padding-bottom: 0px;
}

#securityOverrideDiv {
  padding-top: 10px;
}

div[collapsed] {
  padding-left: 15px;
  background-image: url("chrome://browser/skin/images/arrowright-16.png");
  background-size: 11px 11px;
  background-repeat: no-repeat;
  background-position: left 0.3em;  
}

div[collapsed="true"] {
  background-image: url("chrome://browser/skin/images/arrowright-16.png");
}

div[collapsed="false"] {
  background-image: url("chrome://browser/skin/images/arrowdown-16.png");
}

div[collapsed="true"] > p,
div[collapsed="true"] > div {
  display: none;
}

button {
  padding: 0.3em !important;
}