:root {
  --sso-bg: #f4f6f8;
  --sso-card: #fff;
  --sso-text: #1a1d21;
  --sso-muted: #5c6570;
  --sso-accent: #0d6efd;
  --sso-alert: #842029;
  --sso-alert-bg: #f8d7da;
}

* { box-sizing: border-box; }

body {
  margin: 0;
  font-family: system-ui, -apple-system, "Segoe UI", Roboto, sans-serif;
  background: var(--sso-bg);
  color: var(--sso-text);
}

.sso-shell {
  min-height: 100vh;
  display: flex;
  align-items: center;
  justify-content: center;
  padding: 1.5rem;
}

.sso-card {
  max-width: 28rem;
  width: 100%;
  background: var(--sso-card);
  border-radius: 12px;
  padding: 1.75rem;
  box-shadow: 0 4px 24px rgba(0, 0, 0, 0.08);
}

.sso-card h1 {
  margin: 0 0 0.75rem;
  font-size: 1.35rem;
}

.sso-muted {
  color: var(--sso-muted);
  font-size: 0.95rem;
  line-height: 1.5;
}

.sso-alert {
  background: var(--sso-alert-bg);
  color: var(--sso-alert);
  padding: 0.75rem 1rem;
  border-radius: 8px;
  margin: 1rem 0;
}

.sso-school-list {
  display: flex;
  flex-direction: column;
  gap: 0.75rem;
  margin-top: 1.25rem;
}

.sso-school-option {
  display: flex;
  align-items: center;
  gap: 0.75rem;
  padding: 0.85rem 1rem;
  border: 1px solid #dee2e6;
  border-radius: 8px;
  cursor: pointer;
}

.sso-school-option:has(input:checked) {
  border-color: var(--sso-accent);
  background: #eef4ff;
}

.sso-school-label {
  font-weight: 500;
}

.sso-submit {
  margin-top: 0.5rem;
  width: 100%;
  padding: 0.85rem;
  font-size: 1rem;
  font-weight: 600;
  color: #fff;
  background: var(--sso-accent);
  border: none;
  border-radius: 8px;
  cursor: pointer;
}

.sso-submit:hover {
  filter: brightness(1.05);
}