iBook css and Calibre

[At_Libitum]

Not sure if this is the right place so please feel free to move if needed

I was rummaging around in the internals of iBook, trying to extract the fixed-layout view (book background/frame) when I found that iBook has css hacks included for things done by Calibre

notably I encountered this in the basic style sheet

.calibre > div, .calibre1 > div {
  position: static !important;
}

/* centering hack to support Calibre-generated vertical centered documents */
:root:not([__ibooks_has_multiple_pages]) *[__ibooks_centering_hack^="horizontal-"] {
  min-width: {{.pageWidth}}px;
}
:root:not([__ibooks_has_multiple_pages]) *[__ibooks_centering_hack^="vertical-"] {
  min-height: {{.pageHeight}}px;
}

The latter two likely will not thwart you but the first one might.

anyways, found it curious enough to share