.rrci-calculator {
    max-width: 400px;
    padding: 20px;
    background: #f8f9fa;
    border: 1px solid #ddd;
    border-radius: 8px;
}
.rrci-calculator h2 {
    text-align: center;
}
.rrci-calculator label {
    display: block;
    margin-top: 10px;
}
.rrci-calculator input {
    width: 100%;
    padding: 8px;
    margin-top: 5px;
}
.rrci-calculator button {
    margin-top: 15px;
    padding: 10px;
    width: 100%;
    background-color: #0073aa;
    color: white;
    border: none;
    border-radius: 5px;
    cursor: pointer;
}
#rrci-result {
    margin-top: 15px;
    text-align: center;
    font-weight: bold;
}