body::before {
  content: "";
  position: fixed;
  top: 0; left: 0;
  width: 100%;
  height: 100%;
  background: linear-gradient(45deg,
    #3a78b7,  /* Azul profundo */
    #a2c9f2,  /* Azul claro */
    #60c6cb,  /* Verde-água médio */
    #e6f7ff,  /* Azul muito claro */
    #5a92d6,  /* Azul médio mais saturado */
    #d4ecf9   /* Azul suave claro */
  );
  background-size: 500% 500%;
  animation: gradientFlow 18s ease-in-out infinite;
  z-index: -1;
  opacity: 0.7;
}

@keyframes gradientFlow {
  0% { background-position: 0% 50%; }
  50% { background-position: 100% 50%; }
  100% { background-position: 0% 50%; }
}