/* General Styles */
body {
  font-family: Arial, sans-serif;
  display: flex;
  justify-content: center;
  align-items: center;
  height: 100vh;
  margin: 0;
  background: linear-gradient(120deg, #2193b0, #6dd5ed);
}

/* Calculator Styles */
.calculator {
  background: #fff;
  width: 320px;
  border-radius: 8px;
  overflow: hidden;
  box-shadow: 0 4px 10px rgba(0, 0, 0, 0.3);
}

.display {
  background: #222;
  padding: 10px;
}

#calc-display {
  width: 100%;
  background: #000;
  color: #0f0;
  font-size: 1.5rem;
  border: none;
  padding: 10px;
  text-align: right;
}

.buttons,
.scientific {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 5px;
  padding: 10px;
}

button {
  background: #f0f0f0;
  border: 1px solid #ccc;
  font-size: 1rem;
  padding: 10px;
  border-radius: 4px;
  cursor: pointer;
  transition: background 0.2s ease;
}

button:hover {
  background: #ddd;
}

.scientific.hidden {
  display: none;
}

/* Special Buttons */
button:nth-child(4n) {
  background: #ff8c00;
  color: white;
}

button:nth-child(4n):hover {
  background: #ff6a00;
}

button#equal {
  background: #4caf50;
  color: white;
}

button#equal:hover {
  background: #45a049;
}