Column Count in HTML with the PHP MPDF library

I'm trying to show a pdf with columns, but it does not accept me% c_of css% My code:

<style type="text/css">
#container
{
    width: 100%;
    max-width: 700px;
    margin: 2em auto;
}

.cols
{
    -moz-column-count:3;
    -moz-column-gap: 3%;
    -moz-column-width: 30%;
    -webkit-column-count:3;
    -webkit-column-gap: 3%;
    -webkit-column-width: 30%;
    column-count: 3;
    column-gap: 3%;
    column-width: 30%;
}

.box
{
    margin-bottom: 20px;
}

.box.one
{
    height: 200px;
    background-color: #d77575;
}

.box.two
{
    height: 300px;
    background-color: #dcbc4c;
}

.box.three
{
    background-color: #a3ca3b;
    height: 400px;
}

.box.four
{
    background-color: #3daee3;
    height: 500px;
}

.box.five
{
    background-color: #bb8ed8;
    height: 600px;
}

.box.six 
{
    background-color: #baafb1;
    height: 200px;
}

<div id="container" class="cols">
<div class="box one"></div>
<div class="box two"></div>
<div class="box one"></div>
<div class="box three"></div>
<div class="box two"></div>
<div class="box five"></div>
<div class="box one"></div>
<div class="box two"></div>
<div class="box six"></div>
<div class="box three"></div>
<div class="box two"></div>

This in the browser is perfect, but in the pdf, nothing comes out. Any idea of the problem or any other code of use?

Thank you!