@GeoffR: Just to point out that it's margin-top/margin-bottom and not left/right that's used in Kobo's stylehacks CSS

.
(Apart form that, nothing more to add, not my area of expertise, I'm doing my best impression of a sponge and soaking up knowledge in the background, carry on

).
That does explain why I thought the formatting looked wonky in terms of top/bottom margins in what I'm currently reading (unpadded scene breaks, for instance) ;p.