>> Even with Javascript enabled, I still have to scroll down a full page
>> of white space to get to step 2.
>
> You clicked on one of the platforms?
>
Click on Get Started and you end up at Step 1.
However, there's no indication how to get to Step 2 and you have to
scroll down a page of whitespace before Step 2 comes into view.
IOW, you need a "Step 2" button after Step 1 in the same way you have
a "Step 3" button after Step 2.
I can see what you are doing with the individual links, but someone
might think "I've already choosen an operating system" and not click
on them as it's not clear you are talking about the installation of
GNAT here.
Thinking about it, I think it might be better to combine Steps 1 and 2
together into one installation step and maybe put the detailed
instructions on another page. They will only be installing Ada once
but they will be coming back to your website multiple times and it's
going to get annoying really quickly having to wade through that stuff
if they don't click on the links at the top of the page.
BTW, maybe your links at the top of the page should be three buttons:
Install Ada (instead of Get Started)
Learn Ada (or maybe "Explore Ada")
Advocate Ada