body {
  display: flex;
  flex-direction: column;
  justify-content: center;
  align-items: center;
  margin: 0 auto;
  padding: 0;
  min-height: 100vh;
  font-family: Arial, sans-serif;
  background-color: #f0f0f0;
  gap: 10px;
}

h1 {
  margin: 0;
}

label {
  font-size: 1rem;
  color: #555;
}

input[type="number"] {
  padding: 5px 10px;
  font-size: 1rem;
  border: 1px solid #ccc;
  border-radius: 5px;
  width: 60px;
  text-align: center;
}

button {
  padding: 5px 15px;
  font-size: 1rem;
  color: white;
  background-color: #007bff;
  border: none;
  border-radius: 5px;
  cursor: pointer;
  transition: background-color 0.3s ease;
}

button:hover {
  background-color: #0056b3;
}

button:disabled {
  background-color: #e0e0e0;
  cursor: not-allowed;
}

.grid-container {
  display: flex;
  flex-direction: column;
  gap: 20px;
}

#error {
  color: red;
}