body {
  background-color: #ffe6f0;
  font-family: Arial, sans-serif;
}

.container {
  width: 400px;
  margin: 80px auto;
  padding: 30px;
  background-color: #ffffff;
  text-align: center;
  border-radius: 10px;
}

h1 {
  color: #e91e63;
}

button {
  padding: 10px 20px;
  font-size: 16px;
  background-color: #e91e63;
  color: white;
  border: none;
  border-radius: 5px;
}

.result {
  font-size: 20px;
  margin: 20px 0;
}

/* アニメーション用 */
.animation {
  margin-top: 20px;
  font-size: 18px;
  animation: shake 0.5s infinite;
}

.hidden {
  display: none;
}

@keyframes shake {
  0% { transform: rotate(0deg); }
  25% { transform: rotate(5deg); }
  50% { transform: rotate(0deg); }
  75% { transform: rotate(-5deg); }
  100% { transform: rotate(0deg); }
}