body {
  font-family: Arial, sans-serif;
  background: #f5f5f5;
  color: #333;
  text-align: center;
}

button {
  margin: 10px;
  padding: 10px 20px;
  font-weight: bold;
  cursor: pointer;
}

.modal {
  position: fixed;
  top: 50%;
  left: 50%;
  transform: translate(-50%, -50%);
  background: white;
  padding: 25px;
  border-radius: 8px;
  box-shadow: 0 0 12px rgba(0,0,0,0.3);
  z-index: 1001;
}

.overlay {
  position: fixed;
  top: 0; left: 0;
  width: 100%; height: 100%;
  background: rgba(0,0,0,0.4);
  z-index: 1000;
}

.hidden {
  display: none;
}