Structural section divider that opens deliberate breathing room between stacked sections. Three treatments: mark (a hairline broken by an editable label or an editorial ornament), glow (a precise luminous rule — a chromatic line of light with a soft bloom above and below), and bleed (atmospheric luminance — an elliptical light seam rising from the boundary). One Tone control spans all three — neutral, brand, accent, spectrum, aurora — plus editor-controlled spacing, weight, and an optional draw-in reveal that rides the shared scroll observer.