.btt-c931ab79-btn {
    position: fixed;
    bottom: 20px;
    right: 20px;
    display: flex;
    align-items: center;
    justify-content: center;
    background-color: #000;
    color: #fff;
    width: 40px;
    height: 40px;
    border-radius: 50%;
    cursor: pointer;
    opacity: 0;
    visibility: hidden;
    border: none;
    transition: opacity 0.3s ease, visibility 0.3s ease, background-color 0.3s ease, color 0.3s ease;
    z-index: 9999;
}

.btt-c931ab79-btn.is-visible {
    opacity: 1;
    visibility: visible;
}

.btt-c931ab79-btn:hover {
    background-color: #333;
}