Not gonna work with my iPad, iPhone or MacMini. My PC just boots up for gaming these days, and that's fairly rare.
For all of the faults of PDFs, they are system agnostic. HTML is too, but the install program for offline work in this case is not. Thus the disconnect. Your solution (at the moment) is geared to one OS (obviously the most popular). When it comes to mobile OS, i think the iOS might have that market.
Dude surely you know me better than that by now

You've got Safari. You've got Goodreader or the like which does offline saves of web pages from Safari? Lots of ways of going about it:
Download the zip version and unzip it on PC or iPad. The contents are simply Safari ready web pages saveable offline through Goodreader. Copy over from PC if that's the preferred unzip platform.
Go to the
'Live' version of Treasure and save it where you like. This may not be ideal as I haven't tried saving that to an iPad, so the links may not turn out right. Depends how GoodReader handles them, but it demonstartes it can be done.
Or, heresy, stick a .doc on the old PC and burn a PDF. An online PDF Safari extension or or service might do the same, but it'd be mangled doing the burning on the iPad. The whole game is a small download compared to a PDF, but burning PDFs online off an iPad's processor ain't an option. This won't give full interactivity, but it shows the ease of switching between the options with the original as html.
Basically, last I checked it's good with every major browser.
Overall, you get far, far more 'ownership' this way. You choose what media goes in the rules and can re-arrange, mark, hook-up and save completely personal or group local versions.
You're discussing offline, but if nothing else check out the live page in Safari. It's worth it to see what the autostyling buttons near the top do to theme any game. The download takes a little first time, but not too much as each style only has 6 or 12 images to load at a time.
I should add that I make no claims on how WotC will choose to deliver their media. Treasure doesn't try to be a swap out for a 4e or a Pathfinder, as it's tactically more like poker meets Traveller; but WotC, Pathfinder and Goodman Games will eventually give you various offline options simply because they have to compete over the same gameplay territory and, quite rightly, you guys want rules you own/ physically hold.