body {
    width: 100%;
    margin: 0;
}

main {
    display: block;
}

body > header,
body > main,
body > footer {
    width: 100%;
    margin-right: auto;
    margin-left: auto;
}
@media (min-width: 576px) {
    body > header,
    body > main,
    body > footer {
        max-width: 510px;
        padding-right: 0;
        padding-left: 0;
    }
}
@media (min-width: 768px) {
    body > header,
    body > main,
    body > footer {
        max-width: 700px;
    }
}
@media (min-width: 1024px) {
    body > header,
    body > main,
    body > footer {
        max-width: 950px;
    }
}
@media (min-width: 1280px) {
    body > header,
    body > main,
    body > footer {
        max-width: 1200px;
    }
}
@media (min-width: 1536px) {
    body > header,
    body > main,
    body > footer {
        max-width: 1450px;
    }
}