footer{
    visibility: hidden;
    position: absolute;
    width: 100%;
    bottom: 0;
    left: 0;
    padding: 6em 0 6em 0;
}
footer .f1,
footer .f2{
    width: 50%;
}
footer .f21,
footer .f22,
footer .f23{
    width: 33%;
    line-height: 1.8em;
}
@media only screen and (max-width: 1024px), only screen and (max-device-width: 1024px) {
    footer .f1{
        width: 100%;
        margin-bottom: 3em;
        text-align: center;
    }
    footer .f2{
        width: 100%;
        text-align: center;
    }
}
@media only screen and (max-width: 540px), only screen and (max-device-width: 540px) {
    footer .f21,
    footer .f22{
        width: 100%;
        margin-bottom: 3em;
    }
    footer .f23{
        width: 100%;
    }
}

#divWhat{
    position: fixed;
    width: 50px;
    height: 50px;
    left: 2em;
    bottom: 3em;
    z-index: 99;
}
@media only screen and (max-width: 540px), only screen and (max-device-width: 540px) {
    #divWhat{
        left: 2em;
        bottom: 2em;
    }
}