#ppn-kalkulator {
    max-width: 600px;
    margin: 20px auto;
    background: #ffffff;
    border-radius: 12px;
    border: 1px solid #ccc;
    padding: 20px;
    color: #1b4f88;
    font-family: "Segoe UI", sans-serif;
}

#ppn-kalkulator h2, #ppn-kalkulator h3 {
    color: #1b4f88;
    text-align: center;
}

#ppn-kalkulator label {
    display: block;
    font-weight: bold;
    margin-top: 10px;
}

#ppn-kalkulator input, #ppn-kalkulator select {
    width: 100%;
    padding: 10px;
    margin-top: 5px;
    border-radius: 8px;
    border: 1px solid #ccc;
    margin-bottom: 15px;
}

#ppn-kalkulator .radio-group label {
    display: block;
    margin-bottom: 8px;
}

#ppn-kalkulator button {
    background: #1b4f88;
    color: white;
    border: none;
    border-radius: 8px;
    padding: 12px;
    cursor: pointer;
    width: 100%;
    font-size: 1em;
}