[acee]

Thanks! That was exactly it. The CSS had hard-coded width/height in the main div class:

div.page {position: absolute;top: 0px;left: 0px;width: 1194px;height: 1672px;overflow: hidden;background-size: 1194px 1672px;}
img.backgroundImage {position: absolute;top: 0px;left: 0px;width: 100%;margin: 0px;}
div.linkhotspot {position:absolute;}
div.linkhotspot > a {-webkit-tap-highlight-color:rgba(0,0,0,0);}
span.linkhotspot {display:inline-block;width:100%;height:100%;}

I changed it to this and it helps shrink the page down such that the entire page is visible:

div.page {
	position: absolute;
	top: 0px;
	left: 0px;
	width: 95%;
	height: 100%;
	/*overflow: hidden;*/
	background-size: 100% 100%;
}
img.backgroundImage {position: absolute;top: 0px;left: 0px;width: 100%;margin: 0px;}
div.linkhotspot {position:absolute;}
div.linkhotspot > a {-webkit-tap-highlight-color:rgba(0,0,0,0);}
span.linkhotspot {display:inline-block;width:100%;height:100%;}

The only thing is that the title page display is a little off now... it only displays a thin narrow horizontal strip of the original tile page instead of the whole title page. But that's ok for now, the actual pages display ok when reading the EPUB.

Now to see if the CSS is consistent across all of the volumes in the series...!