.calculator {
    display: grid;
    grid-template-columns: repeat(4, 1fr);
    grid-gap: 10px;
    margin-bottom: 20px;
}

.calculator input[type="text"],
.calculator input[type="number"] {
    grid-column: span 4;
    padding: 10px;
    border: 1px solid #ccc;
    border-radius: 5px;
    font-size: 24px;
    text-align: right;
}

.calculator .btn {
    padding: 15px;
    border: none;
    border-radius: 5px;
    font-size: 18px;
    cursor: pointer;
    transition: background-color 0.3s;
}

.calculator .btn.clear {
    background-color: #ff6347;
    color: #fff;
}

.calculator .btn.equal {
    background-color: black;
    color: #fff;
}

.calculator .btn:hover {
    background-color: #ccc;
}