I was hoping to avoid css as it makes it much more complicated. Is there some sort of java that I can put into the html body?
If something like the <link rel = "stylesheet" type = "text/css" media = "screen and (max-width:2000px)" href = "one.css"> construction --which I'd never tried before-- works reliably for the devices you're targeting, the CSS itself becomes the equivalent of an include file.
The other day I was snooping around someone else's site and found they had twenty-four stylesheets. By actual count. Having two is not going to send you over the top. I do for most pages. I try not to go to three.