

Arguing about which browser does not make much sense to me because ultimately to render HTML with CSS in the way that the designer expected is the whole reason you need CSS.
ePub is interesting, but the functionality supported in the HTML is limited, as is CSS support.
You make an interesting point about JavaScript, but in my experience, the use of it is increasing, not decreasing.
I never said that Firefox, Chrome or Safari was required, there are plenty of light(er) weight browsers around, there’s even a Wikipedia page about it:
https://en.m.wikipedia.org/wiki/Comparison_of_lightweight_web_browsers
My point stands, use a browser.
My excitement is muted by two things:
I want this to work, but so far it just doesn’t.
In case you’re wondering, try running a GUI application on a remote server side by side with one running on another server on the same display and copy/paste data between the two.