.mcb-chat-button {
    position: fixed;
    bottom: 20px;
    right: 20px;
    z-index: 9999;
    background: #0084ff;
    border-radius: 50%;
    padding: 10px;
    box-shadow: 0 4px 8px rgba(0,0,0,0.2);
}
.mcb-chat-button img {
    width: 40px;
    height: 40px;
}