/* Fondo general */
.auth-bg {
  min-height: 100vh;
  display: flex;
  align-items: center;
  justify-content: center;
  background: radial-gradient(circle at top, #111827 0, #020617 60%, #000 100%);
  font-family: system-ui, -apple-system, BlinkMacSystemFont, "Segoe UI", sans-serif;
}

/* Tarjeta de login */
.login-card {
  width: 100%;
  max-width: 420px;
  padding: 2.5rem 2.8rem;
  border-radius: 1rem;
  background: rgba(15, 23, 42, 0.85);
  box-shadow: 0 20px 45px rgba(0, 0, 0, 0.65);
  border: 1px solid rgba(148, 163, 184, 0.35);
  backdrop-filter: blur(18px);
  color: #e5e7eb;
}

/* Logo / título */
.login-card .logo {
  margin: 0 0 0.5rem;
  font-size: 1.6rem;
  font-weight: 700;
  letter-spacing: 0.06em;
  text-transform: uppercase;
  color: #38bdf8;
}

.login-card h2 {
  margin: 0 0 1.5rem;
  font-size: 1.25rem;
  font-weight: 600;
  color: #f9fafb;
}

/* Grupos de campos */
.form-group {
  margin-bottom: 1rem;
}

.form-group label {
  display: block;
  margin-bottom: 0.35rem;
  font-size: 0.9rem;
  color: #9ca3af;
}

.form-group input {
  width: 100%;
  padding: 0.65rem 0.8rem;
  border-radius: 0.5rem;
  border: 1px solid #4b5563;
  background: rgba(15, 23, 42, 0.9);
  color: #e5e7eb;
  font-size: 0.95rem;
  outline: none;
  transition: border-color 0.2s ease, box-shadow 0.2s ease, background 0.2s ease;
}

.form-group input:focus {
  border-color: #38bdf8;
  box-shadow: 0 0 0 1px rgba(56, 189, 248, 0.4);
  background: rgba(15, 23, 42, 1);
}

/* Botón principal */
.btn-primary {
  width: 100%;
  margin-top: 0.5rem;
  padding: 0.7rem 1rem;
  border-radius: 0.65rem;
  border: none;
  background: linear-gradient(135deg, #38bdf8, #0ea5e9);
  color: #0b1120;
  font-weight: 600;
  font-size: 0.98rem;
  cursor: pointer;
  transition: transform 0.12s ease, box-shadow 0.12s ease, filter 0.12s ease;
}

.btn-primary:hover {
  transform: translateY(-1px);
  box-shadow: 0 12px 25px rgba(8, 47, 73, 0.8);
  filter: brightness(1.04);
}

.btn-primary:active {
  transform: translateY(0);
  box-shadow: none;
}

/* Links inferiores */
.links {
  margin-top: 1.2rem;
  display: flex;
  justify-content: center;
  gap: 0.4rem;
  font-size: 0.9rem;
  color: #9ca3af;
}

.links a {
  color: #38bdf8;
  text-decoration: none;
}

.links a:hover {
  text-decoration: underline;
}

/* Mensaje de error */
.alerta-error {
  margin-bottom: 1rem;
  padding: 0.6rem 0.75rem;
  border-radius: 0.5rem;
  border: 1px solid rgba(248, 113, 113, 0.6);
  background: rgba(239, 68, 68, 0.1);
  color: #fecaca;
  font-size: 0.85rem;
}

/* Responsive */
@media (max-width: 480px) {
  .login-card {
    margin: 1.5rem;
    padding: 2rem 1.6rem;
  }
}