.rcc-calculator {
    font-family: Arial, sans-serif;
    max-width: 400px;
    padding: 20px;
    border: 1px solid #ddd;
    border-radius: 10px;
    background: #f9f9f9;
}
.rcc-calculator label {
    display: block;
    margin: 10px 0 5px;
}
.rcc-calculator select {
    width: 100%;
    padding: 8px;
    border-radius: 5px;
    border: 1px solid #ccc;
}
.rcc-output {
    margin-top: 20px;
    font-size: 1.1em;
}