/* Hero image (portada principal) */
.hero-image {
  background-image: linear-gradient(rgba(0,0,0,.4), rgba(0,0,0,.4)), url(heroimag.jpg);
  background-size: cover;
  background-position: center;
  height: 55vh;
  display: flex;
  justify-content: center;
  align-items: center;
  color: #fff;
  font-size: 3rem;
  font-weight: bold;
}