@layer objects {
/* Vertical-rhythm primitive. Children flow vertically with consistent gap.
   Use o-stack--tight / o-stack--loose for density variants. */

.o-stack { display: flex; flex-direction: column; gap: var(--space-4); }
.o-stack--tight { gap: var(--space-2); }
.o-stack--loose { gap: var(--space-6); }
}