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

.calculator {
  width: 300px;
  background-color: #851010;
  border-radius: 8px;
}

#display {
  background-color: #222;
  color: white;
  font-size: 2em;
  padding: 20px;
  text-align: right;
}

.button {
  font-size: 1.5rem;
  padding: 15px;
  background-color: #444;
  color: #FFF;
  border: none;
  border-radius: 5px;
  cursor: pointer;
}

.button:hover {
  background-image: #555;
}

.buttons {
  display: grid;
  padding: 5px;
  grid-template-columns: repeat(4, 1fr);
  gap: 5px;
}