.success-popup {
  position: fixed;
  top: 30%;
  left: 50%;
  transform: translate(-50%, -50%);
  background: rgba(34, 34, 34, 0.95);
  color: #fff;
  padding: 20px 30px;
  border-radius: 10px;
  text-align: center;
  font-size: 16px;
  z-index: 9999;
  animation: popup-fade 0.3s ease;
}

@keyframes popup-fade {
  from { opacity: 0; transform: translate(-50%, -60%); }
  to { opacity: 1; transform: translate(-50%, -50%); }
}

.success-popup button {
  background: #ff4444;
  color: #fff;
  border: none;
  padding: 6px 12px;
  border-radius: 5px;
  margin-top: 10px;
  cursor: pointer;
}

.firework {
  position: fixed;
  width: 6px;
  height: 6px;
  background: hsl(calc(360 * var(--i)), 100%, 60%);
  border-radius: 50%;
  pointer-events: none;
  animation: explode 0.8s ease-out forwards;
}

@keyframes explode {
  0% { transform: scale(0); opacity: 1; }
  100% { transform: scale(3); opacity: 0; }
}