Originally Posted by Jellby
The CSS spec only says it's relative to the container's height, but there's no container, or rather the container's height is not defined, as it's a <div> inside <body>. It seems Adobe-based readers interpret this relative height with respect to the screen (minus margins, statusbar, etc., maybe), at least in some circumstances, but unfortunately that's not guaranteed.
have an explicit sizeóheight: 100%; width: 100%;
in the CSS. This should result in a <div>
that fills the screen.
The SVG scaling rules are then applied within that container, which means that if you tell it to scale proportionally, it should grow to the maximum size that will fit entirely within that div, which is the size of your screen.
If a reader doesn't do that, it's a bug.