Ghost_Ruby_Theme/assets/css/site/layout.css

.site {
    display: flex;
    flex-direction: column;
    min-height: 100vh;
}

.site-content {
    flex-grow: 1;
    padding-top: 30px;
    padding-bottom: 30px;
}

@media (min-width: 992px) {
    .related-column {
        order: 1;
    }

    .content-column {
        order: 2;
    }

    .sidebar-column {
        order: 3;
    }
}