#rotatingHeader {
    height: 500px; /* altezza dello header, personalizzabile */
    background-size: cover;
    background-position: center;
    background-repeat: no-repeat;
    transition: background-image 1s ease-in-out;
}
  
.small-heading {
  font-size: 2.2rem; /* oppure usa px: es. 18px */
}