html, body {
  width: 100%;
  height: 100%;
  margin: 0; padding: 0;
}

body {
  font-size: 0.875rem;
  height: 100%;
  display: grid;
  grid-template-rows: auto 1fr auto;
}

.loginform {
  display: grid;
  place-items: center;
  height: 100%;
}

.loginform form {
  width: 40ch;
}