.auth-bg {
  min-height: 100vh;
  display: flex; align-items: center; justify-content: center;
  padding: 24px;
  background:
    radial-gradient(circle at 15% 15%, var(--brand-tint) 0%, transparent 45%),
    var(--paper);
}
.auth-layout { width: 100%; max-width: 400px; }
.auth-card { width: 100%; }

@media (max-width: 480px) {
  .card { padding: 24px; }
  .card--tag { padding-left: 38px; }
}