* {
  box-sizing: border-box;
  font-family: Arial, sans-serif;
}

body {
  align-items: center;
  min-height: 100vh;
  background-color: #f4f4f9;
  margin: 0;
}

#layar {
  width: 50%;
  height: 50px;
  background-color: #222;
  color: #fff;
  border: none;
  border-radius: 6px;
  font-size: 24px;
  text-align: left;
  padding: 10px;
  margin-bottom: 15px;
}

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

button {
  height: 50px;
  border: none;
  border-radius: 6px;
  font-size: 18px;
  background-color: #555;
  color: #fff;
}

button:hover {
  background-color: #777;
}

button.operator {
  background-color: #ff9500;
}

button.operator:hover {
  background-color: #e08400;
}

button.aksi {
  background-color: #a5a5a5;
  color: #000;
}

button.aksi:hover {
  background-color: #8e8e8e;
}