Whitespace separator utilities for horizontal, vertical, and flex-fill spacing. Uses --spacing (4px base unit) for sizing.
.spacer / .spacer-h — block-level vertical spacing (default 1rem = 16px)..spacer-v — inline horizontal spacing between inline/inline-block elements..spacer-fill — fills remaining space in a flex container (like flex: auto).spacer-{n} where n is a multiple of --spacing (e.g. spacer-4 = 16px, spacer-10 = 40px).