body {
    font-family: Arial, sans-serif;
    margin: 0;
    padding: 0;
    display: flex;
    justify-content: center;
    align-items: center;
    height: 100vh;
    background-color: #f0f0f0;
}

.calculator {
    background-color: #ffffff;
    padding: 2rem;
    border-radius: 1rem;
    box-shadow: 0 4px 6px rgba(0, 0, 0, 0.1);
}

input {
    width: 60px;
}

button {
    background-color: #007BFF;
    border: none;
    color: white;
    padding: 5px 15px;
    cursor: pointer;
    border-radius: 5px;
    margin-left: 10px;
}

button:hover {
    background-color: #0056b3;
}