body {
    display: flex;
    flex-direction: column;
    min-height: 100vh;
    margin: 0;
}
main {
    flex: 1;
}

@media (min-width: 576px) {
    .container,.container-sm {
        max-width:540px
    }
}

@media (min-width: 768px) {
    .container,.container-md,.container-sm {
        max-width:720px
    }
}

@media (min-width: 992px) {
    .container,.container-lg,.container-md,.container-sm {
        max-width:960px
    }
}

@media (min-width: 1200px) {
    .container,.container-lg,.container-md,.container-sm,.container-xl {
        max-width:960px
    }
}

@media (min-width: 1400px) {
    .container,.container-lg,.container-md,.container-sm,.container-xl,.container-xxl {
        max-width:960px
    }
}