.back-to-top-btn {
    opacity: 0 !important;
    visibility: hidden !important;
    pointer-events: none;
    transition: opacity 0.3s ease, visibility 0.3s ease !important;
}

.back-to-top-btn.is-visible {
    opacity: 1 !important;
    visibility: visible !important;
    pointer-events: auto;
}