<style>

.glowfriends {
  animation: rainbowGlow 4s infinite;
}

@keyframes rainbowGlow {
  0%   { filter: drop-shadow(0 0 15px red); }
  25%  { filter: drop-shadow(0 0 15px violet); }
  50%  { filter: drop-shadow(0 0 15px blue); }
  75%  { filter: drop-shadow(0 0 15px green); }
  100% { filter: drop-shadow(0 0 15px red); }
}

</style>
