h2 {
  text-align: center;
  margin: 20px 0;
}

h2 a {
  color: #1a73e8;
  text-decoration: none;
  font-size: 1.2rem;
}

h2 a:hover {
  text-decoration: underline;
}

#calculator {
  width: 300px;
  margin: 50px auto;
  border: 2px solid #ccc;
  border-radius: 10px;
  padding: 10px;
  box-shadow: 0 0 10px rgba(0, 0, 0, 0.1);
}

#display {
  width: 100%;
  height: 50px;
  font-size: 2rem;
  text-align: right;
  border: none;
  background-color: #f0f0f0;
  padding: 5px;
  box-sizing: border-box;
}

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

.buttons button {
  height: 60px;
  font-size: 1.5rem;
  border: 1px solid #ccc;
  border-radius: 5px;
  cursor: pointer;
}

.buttons button:hover {
  background-color: #f0f0f0;
}

.operator {
  background-color: #f0ad4e;
  color: white;
}

.clear {
  background-color: #d9534f;
  color: white;
}

.equals {
  background-color: #5cb85c;
  color: white;
  grid-column: span 2;
}