Percentages for things like width or height of an element are relative to the size of the enclosing container. If that enclosing container is not a fixed size, then neither is a percentage of that size. If it is a fixed size, then a percentage of that size should always be the same.[/LIST]
That's helpful, thanks. When I added 'position:absolute' to the body tag in the CSS, I mostly solved the problem. I also understand, you need to add the page size in pixels. In some contexts I have seen the page size added to the body tag and sometimes to a div tag, which is used on each page to set the size. Does it matter which way you do it or is this a difference between epub and mobi versions?
The reason I ask, is that I have completed a fixed layout eBook, with the page dimensions added to the body tag, and with a separate div tag for each page, which I have used to identify and format all the elements on each page. I suppose, I should also add in the CSS width and height to each of these divs, but when I do it doesn't seem to make any difference. I still have the problem that there is a slight variation in the flow of the text, when I transfer the file from my computer to my Kindle Fire.