This is more like a readability mode than a responsive website.
It's a button you click to automatically make a fixed-layout PDF fluid and easier to read on mobile.
You'd still author the document the same way without considering multiple device sizes. When the PDF needs to be reproduced faithfully (printing) it would still appear as the creator intended.
It's a button you click to automatically make a fixed-layout PDF fluid and easier to read on mobile.
You'd still author the document the same way without considering multiple device sizes. When the PDF needs to be reproduced faithfully (printing) it would still appear as the creator intended.