#back{
    width: 150px;
    height: 150px;
    background-image: url(../img/volver.svg);
    background-position: 90px 85px;
    background-size: 30px;
    background-repeat: no-repeat;
    position: absolute;
    z-index: 4;
    background-color: #4BD395;
    border-radius: 100%;
    left: -75px;
    top: -75px;
    cursor: pointer;
}

#help{
    width: 150px;
    height: 150px;
    background-image: url(../img/ayuda.png);
    background-position: 25px 80px;
    background-size: 40px;
    background-repeat: no-repeat;
    position: absolute;
    z-index: 4;
    background-color: #4BD395;
    border-radius: 100%;
    right: -75px;
    top: -75px;
    cursor: pointer;
}