.brand-logo {
    margin-top: 0px;
    margin-bottom: 10px;
    font-family: sans-serif;
    font-size: 3rem;
    background: linear-gradient(to right, #ef5350, #f48fb1, #7e57c2, #2196f3, #26c6da, #43a047, #eeff41, #f9a825, #ff5722);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
  }

.header{
   background-image: url(https://www.alikonweb.it/images/banners/blue-clouds-day-fluffy-53594.webp);
  background-size: cover;
  background-repeat: no-repeat;
  background-attach: fixed;
  animation: animate-bg 50s infinite linear;
}

@keyframes animate-bg {
  from { background-size: 100%; background-position: 0% 0%; }
  50% { background-size: 120%; background-position: 0% 20% }
  to { background-size: 100%; background-position: 0% 0%; }
}