body {
  display: flex;
  justify-content: center;
  align-items: center;
  min-height: 100vh;
  margin: 0;
  font-family: Arial, sans-serif;
  background: transparent;
}

.timer-container {
  text-align: center;
}

#timer {
  font-size: 72px;
  font-weight: bold;
  color: #333;
  margin: 20px 0;
}

button {
  font-size: 18px;
  padding: 10px 20px;
  margin: 5px;
  border: none;
  border-radius: 5px;
  cursor: pointer;
  transition: background-color 0.3s;
}

#startBtn {
  background-color: #4caf50;
  color: white;
}

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

button:hover {
  opacity: 0.9;
}