body {
  display: flex;
  justify-content: center;
  align-items: center;
  height: 100vh;
 background: linear-gradient(145deg, #383434, #121212, #383434);

  font-family: Arial, sans-serif;
}

.calculator {
  background-color: #1e1e1e; 
  padding: 20px;
  border-radius: 16px;
  box-shadow: 0px 8px 20px rgba(0,0,0,0.5);
}

.display {
  width: 100%;
  height: 50px;
  margin-bottom: 15px;
  text-align: right;
  padding: 7px;
  font-size: 24px;
  border-radius: 10px;
  border: none;
  background-color: #2a2a2a; 
  color: #f0f0f0; 
}

.buttons {
  display: flex;
  flex-direction: column;
  gap: 12px;
}

.row {
  display: flex;
  gap: 12px;
}

button {
  flex: 1;
  padding: 15px 0;
  font-size: 18px;
  border-radius: 12px;
  border: none;
  background-color: #333; 
  color: #f0f0f0;
  cursor: pointer;
  transition: all 0.2s;
}

button:hover {
  background-color: #555; 
}

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

.operator:hover {
  background-color: #ffa733;
}

.equals {
  background-color: #28a745; 
  color: #fff;
  flex: 2;
}

.equals:hover {
  background-color: #3fd165;
}

.special {
  background-color: #d32f2f; 
  color: #fff;
}

.special:hover {
  background-color: #e53935;
}