body {
  display: flex;
  justify-content: center;
  align-items: center;
  height: 100vh;
  background:#333333;
  font-family: Arial, sans-serif;
}

.calculator {
  background: black;
  padding: 20px;
  border-radius: 20px;
  box-shadow: 0 10px 25px rgba(0,0,0,0.2);
  width: 280px;
  height: 450px;
}

.display {
  width: 100%;
  height: 50px;
  margin-bottom: 15px;
  font-size: 1.5rem;
  text-align: right;
  padding: 10px;
  border: none;
  border-radius: 10px;
  color:white;
  background-color:black;

}

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

button {
  padding: 20px;
  font-size: 1.2rem;
  border: none;
  border-radius: 50%;
  color: white;
  cursor: pointer;
  transition: background 0.3s;
}

button:hover {
  background: black;
}
#op {
    background-color:#f57c00;
    color: white;
}
#eq {
    background-color:#333333;
}
#ok {
    background-color:#545454;
    color: white;
}