Scroll-padding-right property is set on the container, so that the snap position of child elements is offset by a distance to the right of the container.
In this case, snap position is set to end in x direction, so the element in focus should snap into place at the very right of the container. But instead, because of the scroll-padding-right value, the element in focus is offset by a 20px distance from the right side of the container to the child element.