html,
body {
    min-height: 100%;
}

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

main {
    flex: 1 0 auto;
}

.gb-footer { padding: 28px 0; background: #000; color: #d6e4f1; font: 14px/1.6 Roboto; }
.gb-footer { flex: 0 0 auto; margin-top: auto; }
.gb-footer a { color: #fff; }