body {
    margin: 0;
    padding: 0;
    font-family: 'source-sans-pro', Helvetica, Arial, sans-serif;
    font-size: 14px;
}
.demo_wrapper {
    width: 100%;
    margin: 0 auto;
}
@media only screen and (max-device-width: 800px), screen and (max-width: 800px) {
    .demo_wrapper {
        width: 100%;
    }
}
.demo_block {
    width: 100%;
}