Snap position must be placed on bottom of the child elements for scroll-margin-bottom to work. On pages written in English the snap position can normally be set on bottom of child elements by setting scroll-snap-align to "end none" because block direction is downwards. But, if we change block direction with the writing-mode property value set to "vertical-rl", the snap position changes from bottom to left side of the child elements. With the code like this the scroll-margin-bottom property no longer works.