@media only screen and (min-width:1280px) {
    .content {
        width: 68%;
    }
    .sidebar {
        width: 30%;
    }
}

@media only screen and (min-width:900px) and (max-width:1279px) {
    .content {
        width: 68%;
    }
    .sidebar {
        width: 30%;
    }
}

@media only screen and (min-width:501px) and (max-width:899px) {
    .content {
        width: 100%;
    }
    .sidebar {
        display: none;
    }
}

@media only screen and (max-width:500px) {
    .content {
        width: 100%;
    }
    .sidebar {
        display: none;
    }
}