.calculator {
  border: 3px solid #444;
  border-radius: 10px;
  padding: 20px;
  width: fit-content;
  margin: 50px auto;
  background-color: #1e1e2f;
  box-shadow: 0 0 10px rgba(0, 0, 0, 0.5);
}

.buttons {
    display: grid;
    grid-template-columns: repeat(4,1fr);
    gap: 10px;
}

button {
  padding: 20px;
  font-size: 18px;
  border: none;
  border-radius: 5px;
  background-color: #2d2d3c;
  color: white;
  cursor: pointer;
  transition: background 0.2s ease;
}

#display {
  width: 93%;
  height: 50px;
  font-size: 24px;
  text-align: right;
  padding: 10px;
  margin-bottom: 15px;
  border: none;
  background-color: #2e2e3e;
  color: white;
  border-radius: 5px;
}