Why not just use an already established format like epub or mobi? And then you only need one file, note one for phones and one for larger devices...
Curious, are you using a content management system like ArborText so you only have to devlope it once or are you authoring it in a traditional layout tool and then duplicating and re-organizing it for each platform?Designing a consistent UX for the platform audiences are on is one of our principles. Here's the list of formats for #ZweihanderRPG:
Traditional Print
ePub
Kindle
Traditional digital pdf (ePDF)
Phone PDF
Roll20 Compendium (Dec 2019)
HTML5 SRD (2020)
My wife and I had the same reaction to this press release: how is it revolutionary to have a larger font to make it easier to read and to reformat it? It's not different than a mobile view and a desktop view for a website...
Well, according to the post a couple above yours, epub format (and others) is/are available.A for effort, C- for execution. A proper illustrated ePub would have been a better choice. (and you can bind custom fonts into an ePub.)