Number of colums footer at tablets

Hi Kriesi,

I’m using a footer width 4 widgets. I would like to show them like this:

Desktop – 4 colums next to eachother
Tablet – 2 colums next to eachother
Mobile – 1 column

I found this code:

#footer .av_one_fourth:nth-child(1) {
    width: 20.5%;
}

#footer .av_one_fourth:nth-child(2) {
    width: 20.5%;
}

#footer .av_one_fourth:nth-child(3) {
    width: 20.5%;
}

#footer .av_one_fourth:nth-child(4) {
    width: 20.5%;
}

This code does the job, but it also affect the way of showing at desktops and it only works for the first 2 colums.