.fade-in {
  opacity: 0;
  transform: translateY(18px);
  animation: fadeInUp 0.8s ease-out forwards;
}
@keyframes fadeInUp {
  from {
    opacity: 0;
    transform: translateY(18px);
  }
  to {
    opacity: 1;
    transform: translateY(0);
  }
}
.button,
.icon-button,
.nav-list a,
.back-to-top {
  transition: transform 180ms ease, background 180ms ease, color 180ms ease, border-color 180ms ease;
}
.button:hover,
.icon-button:hover,
.back-to-top:hover,
.nav-list a:hover {
  transform: translateY(-1px);
}