html,
body {
  height: 100%;
  background: #f5f5f5;
}

body {
  display: flex;
  align-items: center;
  justify-content: center;
}

.form-signin {
  max-width: 750px;
}

#results {
  opacity: 0;
  transition: opacity .5s;
}

#results.active {
  opacity: 1;
}