.coin {
  width: 225px;
  height: 224px;
  background-size: cover; /* this makes the image fill the circle */
  background-image: url(/static/images/coin-head.png);
  border-radius: 50%;
  margin: 20px auto;
  box-shadow: 0 10px 20px rgba(0, 0, 0, 0.3);
  cursor: pointer;
  transition: transform 0.2s;
}
.coin:hover {
  transform: scale(1.05);
}
button {
  padding: 15px 30px;
  font-size: 18px;
  background: #4caf50;
  color: white;
  border: none;
  border-radius: 10px;
  cursor: pointer;
  margin: 10px;
}
button:hover {
  background: #45a049;
}
#result {
  font-size: 24px;
  font-weight: bold;
  margin-top: 20px;
  min-height: 30px;
}
@keyframes spin {
  0% {
    transform: rotateY(0deg);
  }
  50% {
    transform: rotateY(1800deg);
  }
  100% {
    transform: rotateY(3600deg);
  }
}
.coin.spinning {
  animation: spin 1.5s cubic-bezier(0.5, 0, 0.5, 1);
}