gecko-dev/browser/devtools/framework/connect/connect.css

:root {
  font: caption;
}

html {
  background-color: #111;
  background-image: url("chrome://browser/skin/newtab/noise.png");
}

body {
  font-family: Arial, sans-serif;
  color: white;
  max-width: 600px;
  margin: 30px auto 0;
  box-shadow: 0 2px 3px black;
  background-color: #3C3E40;
}

h1 {
  margin: 0;
  padding: 20px;
  background-color: rgba(0,0,0,0.12);
  background-image: radial-gradient(ellipse farthest-corner at center top , rgb(159, 223, 255), rgba(101, 203, 255, 0.3)), radial-gradient(ellipse farthest-side at center top , rgba(101, 203, 255, 0.4), rgba(101, 203, 255, 0));
  background-size: 100% 2px, 100% 5px;
  background-repeat: no-repeat;
  border-bottom: 1px solid rgba(0,0,0,0.1);
}

label {
  display: block;
  margin: 10px;
}

label > span {
  display: inline-block;
  min-width: 150px;
  text-align: right;
  margin-right: 10px;
}

#submit {
  margin-left: 160px;
}

input:invalid {
  box-shadow: 0 0 2px 2px #F06;
}

section {
  min-height: 160px;
  margin: 60px 20px;
  display: none; /* By default, hidden */
}

.error-message {
  color: red;
}

.error-message:not(.active) {
  display: none;
}

body:not(.actors-mode):not(.connecting) > #connection-form {
  display: block;
}

body.actors-mode > #actors-list {
  display: block;
}

body.connecting > #connecting {
  display: block;
}

#connecting {
  text-align: center;
}

#connecting > p > img {
  vertical-align: top;
}

.actors {
  padding-left: 0;
}

.actors > a {
  display: block;
  margin: 5px;
  padding: 5px;
  color: white;
}

.remote-process {
  font-style: italic;
  opacity: 0.8;
}

footer {
  padding: 10px;
  background-color: rgba(0,0,0,0.12);
  border-top: 1px solid rgba(0,0,0,0.1);
  font-size: small;
}

footer > a,
footer > a:visited {
  color: white;
}