body {
  font-family: Arial, sans-serif;
  text-align: center;
  background-color: #f4f4f4;
  padding: 2rem;
}

h1 {
  margin-bottom: 2rem;
}

#display {
  font-size: 3rem;
  font-weight: bold;
  background: #fff;
  display: inline-block;
  padding: 1rem 2rem;
  border-radius: 10px;
  box-shadow: 0 0 15px rgba(0, 0, 0, 0.1);
  margin-bottom: 2rem;
}

.buttons button {
  font-size: 1rem;
  padding: 0.75rem 1.5rem;
  margin: 0.5rem;
  border: none;
  border-radius: 6px;
  cursor: pointer;
}

#start-btn {
  background-color: #28a745;
  color: white;
}

#stop-btn {
  background-color: #ffc107;
  color: black;
}

#reset-btn {
  background-color: #dc3545;
  color: white;
}