body.modal-open {
    overflow: hidden !important;
    position: fixed;
    width: 100%;
}

#welcomeGuideModal .modal-dialog {
    max-width: 600px;
    width: 100%;
    margin: 1.75rem auto;
}

@media (max-width: 576px) {
    #welcomeGuideModal .modal-dialog {
        max-width: 95vw;
        margin: 1rem auto;
    }
}