.calculadora {
    width: 100%;
    border-collapse: collapse;
    margin-top: 20px;
    font-family: Arial, sans-serif;
}

.calculadora th,
.calculadora td {
    border: 1px solid #ddd;
    padding: 10px;
    text-align: center;
}

.calculadora th {
    background-color: #f7f7f7;
    font-weight: bold;
}

.calculadora-input {
    border: 1px solid orange;
    padding: 6px;
    width: 90%;
    text-align: right;
    background-color: #fff;
}