The .stack applies vertical rhythm for elements. Based on the Owl selector, spacing between the elements is arranged. There are various reasons this pattern does not use the gap property. The most common reason is that this implementation allows for more control on exceptions (e.g. have a smaller gap on h2 + p).
Utility classes
The way .stack behaves can be controlled with several utility classes.
.stack-g-<name>: set the gap between the elements, based on$feo-sizes. Note, this setting works withorientationandwriting-directionCSS properties..stack-grow: sets the margin of the element tomargin-<top/left>: auto. This allows the element to grow and take the available space (similar toflex-grow: 1).