#qr-service-app {
    max-width: 420px;
    margin: 40px auto;   /* 👈 ESTO lo centra horizontalmente */
    background: #fff;
    padding: 20px;
    border-radius: 10px;
    box-shadow: 0 10px 30px rgba(0,0,0,.1);
    font-family: Arial, sans-serif;
}

#qr-service-app h2 {
    text-align: center;
    margin-bottom: 15px;
}

#qr-service-app input,
#qr-service-app textarea,
#qr-service-app select {
    width: 100%;
    padding: 10px;
    margin-bottom: 10px;
    border-radius: 6px;
    border: 1px solid #ccc;
}

.qr-btn {
    width: 100%;
    background: #25D366;
    color: #fff;
    padding: 12px;
    border: none;
    border-radius: 6px;
    font-size: 16px;
    cursor: pointer;
}

.qr-btn:hover {
    background: #1ebc5c;
}

#qr-preview {
    display: none;
    text-align: center;
    margin-top: 15px;
}

#qr-preview img {
    width: 100%;
    max-width: 300px;
}