.hearts span {
  position: fixed;
  bottom: -20px;
  font-size: 22px;
  animation: float 6s linear infinite;
}

@keyframes float {
  0% {
    transform: translateY(0) scale(1);
    opacity: 1;
  }
  100% {
    transform: translateY(-100vh) scale(1.5);
    opacity: 0;
  }
}