body {
  margin: 0;
  padding: 0;
  font: normal 16px Arial, Helvetica, sans-serif;
}

#particles-js {
  background: firebrick;
  height: 400px;
}

#login {
  background: #FFF;
  opacity: 0.9;
  padding: 2em;
  border: 2px solid #CCC;
  position: absolute;
  top: 100px;
  left: 50px;
}

#login input[type="text"],
#login input[type="password"] {
  padding: 7px;
  margin-bottom: 10px;
  border: 1px solid #CCC;
}