.space {
    width: 100%;
    flex: 0 0 auto;
}

.space--xs { height: 8px; }
.space--sm { height: 16px; }
.space--md { height: 24px; }
.space--lg { height: 40px; }
.space--xl { height: 64px; }
.space--2xl { height: 96px; }

@media (max-width: 640px) {
    .space--xs { height: 6px; }
    .space--sm { height: 12px; }
    .space--md { height: 18px; }
    .space--lg { height: 28px; }
    .space--xl { height: 40px; }
    .space--2xl { height: 56px; }
}