/* 全体のデザイン */
body {
  font-family: 'Arial', sans-serif;
  display: flex;
  justify-content: center;
  align-items: center;
  height: 100vh;
  margin: 0;
  background-color: #f4f4f9;
}

.timer {
  text-align: center;
  background: #333;
  padding: 40px 50px;
  border-radius: 15px;
  box-shadow: 0 4px 20px rgba(0, 0, 0, 0.3);
}

.time {
  font-size: 72px;
  margin-bottom: 30px;
  font-weight: bold;
  letter-spacing: 2px;
  color: #f0f0f0;
}

.buttons {
  display: flex;
  gap: 20px;
  justify-content: center;
}

button {
  padding: 15px 30px;
  font-size: 20px;
  font-weight: bold;
  cursor: pointer;
  border: none;
  border-radius: 8px;
  transition: 0.3s ease;
}

#startStop {
  background-color: #4CAF50;
  color: white;
}

#startStop:hover {
  background-color: #45a049;
}

#reset {
  background-color: #f44336;
  color: white;
}

#reset:hover {
  background-color: #e53935;
}

button:disabled {
  background-color: #cccccc;
  cursor: not-allowed;
}

/* ボタンのホバー効果 */
button:hover {
  transform: scale(1.1);
}

/* ボタンが無効なとき */
button:disabled {
  background-color: #d3d3d3;
  cursor: not-allowed;
}