body {
    font-family: Arial, sans-serif;
    text-align: center;
    background-color: #f4f4f4;
}

.calculator {
    width: 250px;
    margin: 50px auto;
    padding: 20px;
    background: white;
    box-shadow: 0 4px 8px rgba(0, 0, 0, 0.2);
    border-radius: 10px;
}

input {
    width: 100%;
    height: 40px;
    text-align: right;
    font-size: 1.2em;
    margin-bottom: 10px;
}

.buttons button {
    width: 48px;
    height: 48px;
    font-size: 1.2em;
    margin: 5px;
    cursor: pointer;
    border: none;
    background: #ddd;
}

.buttons button:hover {
    background: #bbb;
}