body {
  background-color: #0b4e4f;
}

.calculator {
  background-color: #0b4e4f;
  max-width: 400px;
  box-shadow: 0 4px 10px rgba(0, 0, 0, 0.4);
}

.display {
  background-color: #5a999b;
  border: none;
  font-size: 1.5rem;
  height: 60px;
  border-radius: 10px;
  color: wheat;
}

.calc-btn {
  background-color: #5a999b;
  color: wheat;
  width: 100%;
  height: 50px;
  font-weight: bold;
  border-radius: 25px;
  box-shadow: 1px 2px 2px rgba(0, 0, 0, 0.4);
  border: none;
}

.calc-btn:hover {
  background-color: #6fb5b8;
}

.zero {
  border-radius: 25px;  
  width: 100%;
}