.trecolonne {
    -webkit-column-count: 3; /* Chrome, Safari, Opera */
    -moz-column-count: 3; /* Firefox */
    column-count: 3;

    -webkit-column-gap: 10px; /* Chrome, Safari, Opera */
    -moz-column-gap: 10px; /* Firefox */
    column-gap: 10px;

    /*-webkit-column-rule: 4px outset #ff00ff; /* Chrome, Safari, Opera */
    /*-moz-column-rule: 4px outset #ff00ff; /* Firefox */
    /*column-rule: 4px outset #ff00ff;*/

}

@media only screen and (max-width: 2040px) {
}


@media only screen and (max-width: 1200px) {
}

@media only screen and (max-width: 1024px) {
    .trecolonne {
        -webkit-column-count: 1; /* Chrome, Safari, Opera */
        -moz-column-count: 1; /* Firefox */
        column-count: 1;

        -webkit-column-gap: 10px; /* Chrome, Safari, Opera */
        -moz-column-gap: 10px; /* Firefox */
        column-gap: 10px;

        /*-webkit-column-rule: 4px outset #ff00ff; /* Chrome, Safari, Opera */
        /*-moz-column-rule: 4px outset #ff00ff; /* Firefox */
        /*column-rule: 4px outset #ff00ff;*/

    }
}

@media only screen and (max-width: 480px) {    
}

@media only screen and (max-width: 320px) {
}