.fondo-principal {
    background-image: linear-gradient(rgba(0, 0, 0, 0.3), rgba(0, 0, 0, 0.3)), url("../img/bg.jpg");
    background-size: cover;
    background-repeat: no-repeat;
    background-position: center center;
}
.texto-claro{
    color: #d6d6d6;
}

html, body {
    height: 100%;
  }