.atendente {
    position: fixed;
    right: 5%;
    top: 90%;
    transform: translateY(-50%);
    width: 50px;
    height: 50px;
    float: right;
    background-image: url("imagens/atendente.png");
    background-repeat: no-repeat;
    background-size: cover;
    background-attachment: fixed;
}

.atendente_b{
    width: 50px;
    height: 50px;
    opacity: 0;
}