@media all and (max-width: 1600px) {
    .responsive-grid >.ui-block-a,
    .responsive-grid >.ui-block-b,
    .responsive-grid >.ui-block-c,
    .responsive-grid >.ui-block-d,
    .responsive-grid >.ui-block-e {
        width: 48% !important;
        float:left;
    }
}

@media all and (max-width: 800px) {
    .responsive-grid >.ui-block-a,
    .responsive-grid >.ui-block-b,
    .responsive-grid >.ui-block-c,
    .responsive-grid >.ui-block-d,
    .responsive-grid >.ui-block-e {
        width: 100% !important;
        float:none;
    }
}