/* Reset dan font dasar */
body {
  margin: 0;
  padding: 0;
  font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
  background-color: #f4f4f4;
  display: flex;
  align-items: center;
  justify-content: center;
  height: 100vh;
}

/* Container kalkulator */
.calculator {
  background-color: #fff;
  padding: 20px;
  border-radius: 16px;
  box-shadow: 0 8px 20px rgba(0, 0, 0, 0.1);
  max-width: 320px;
  width: 100%;
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  grid-gap: 12px;
}

/* Display */
#display {
  grid-column: span 4;
  height: 60px;
  font-size: 24px;
  padding: 0 10px;
  text-align: right;
  border: none;
  background-color: #eaeaea;
  border-radius: 10px;
}

/* Tombol kalkulator */
button {
  height: 60px;
  font-size: 20px;
  border: none;
  border-radius: 12px;
  background-color: #f0f0f0;
  cursor: pointer;
  transition: background-color 0.2s ease;
}

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

button:active {
  background-color: #ccc;
}

/* Tombol operator */
button:nth-child(4n) {
  background-color: #4CAF50;
  color: white;
}

button:nth-child(4n):hover {
  background-color: #45a049;
}

/* Tombol sama dengan */
.equals {
  grid-column: span 4;
  background-color: #2196F3;
  color: white;
  font-size: 24px;
}

.equals:hover {
  background-color: #1976D2;
}

/* Tombol clear */
button:contains("C") {
  background-color: #ff5252;
  color: white;
}