.auth-shell {
  --auth-card-bg: rgba(255, 255, 255, 0.96);
  --auth-card-border: rgba(209, 213, 219, 0.9);
  --auth-card-shadow: 0 1.5rem 3.5rem rgba(15, 23, 42, 0.12);
  --auth-spinner-track: #dbe3f0;
  --auth-spinner-accent: var(--color-primary);
  display: grid;
  min-height: 100vh;
  place-items: center;
  padding: var(--space-6);
  background:
    radial-gradient(circle at top left, rgba(65, 105, 225, 0.14), transparent 24rem),
    linear-gradient(135deg, rgba(65, 105, 225, 0.08), rgba(255, 221, 87, 0.08) 52%, transparent 52%),
    var(--color-page);
}

.auth-card {
  width: min(100%, 32rem);
  padding: var(--space-8);
  background: var(--auth-card-bg);
  border: 1px solid var(--auth-card-border);
  border-radius: var(--radius-lg);
  box-shadow: var(--auth-card-shadow);
}

.auth-card__title {
  margin: 0;
  color: var(--color-heading);
  font-size: 1.5rem;
  line-height: 1.25;
}

.auth-card__copy {
  margin: var(--space-2) 0 0;
  color: var(--color-muted);
}

.auth-card__body {
  margin-top: var(--space-5);
}

.auth-card__footer {
  margin-top: var(--space-6);
  text-align: center;
}

.auth-card__footer a {
  color: var(--color-primary);
  font-weight: 700;
}

.auth-card__footer a:hover {
  color: var(--color-primary-dark);
}

.auth-transition {
  display: flex;
  flex-direction: column;
  align-items: center;
  text-align: center;
  gap: var(--space-4);
}

.auth-transition__spinner {
  width: 3rem;
  height: 3rem;
  border: 4px solid var(--auth-spinner-track);
  border-top-color: var(--auth-spinner-accent);
  border-right-color: var(--auth-spinner-accent);
  border-radius: 50%;
  animation: auth-transition-spin 0.8s linear infinite;
}

@keyframes auth-transition-spin {
  to {
    transform: rotate(360deg);
  }
}

@media (max-width: 480px) {
  .auth-shell {
    padding: var(--space-4);
  }

  .auth-card {
    padding: var(--space-6);
  }
}

@media (prefers-reduced-motion: reduce) {
  .auth-transition__spinner {
    animation: none;
  }
}

@media (prefers-color-scheme: dark) {
  .auth-shell {
    --auth-card-bg: rgba(17, 24, 39, 0.94);
    --auth-card-border: rgba(61, 75, 102, 0.95);
    --auth-card-shadow: 0 1.5rem 3.5rem rgba(0, 0, 0, 0.38);
    --auth-spinner-track: #2f3b52;
    --auth-spinner-accent: #9db4ff;
    background:
      radial-gradient(circle at top left, rgba(109, 141, 255, 0.18), transparent 24rem),
      linear-gradient(135deg, rgba(109, 141, 255, 0.11), rgba(255, 221, 87, 0.07) 52%, transparent 52%),
      var(--color-page);
  }
}