When resizing the browser window with the new template, the sidebar content gets a min-height set by makeToggle(). However when you switch to tablet mode, the sidebar is a lot wider and thus the height of some elements like longer text blocks is decreased which means that the min-height is now too high so there is some whitespace displayed below the sidebar. This can be reproduced on dokuwiki.org, start with a wide browser window (desktop mode), then resize till the sidebar collapses, then expand again to desktop mode, then resize again to tablet mode and expand the sidebar - then there should be additional whitespace below the sidebar like on the attached screenshot. I think the fix could be to remove the min-height again once the animation has completed.