* {
  margin: 0;
  padding: 0;
}
.vertical-shake {
  animation: vertical-shaking 0.35s infinite;
}
@keyframes vertical-shaking {
  0% { transform: translateY(0) }
  25% { transform: translateY(5px) }
  50% { transform: translateY(-5px) }
  75% { transform: translateY(5px) }
  100% { transform: translateY(0) }
}
img {
  max-width: 100%;
  height: auto;
}