Thanks for the responses. Yes, there used to be a "download all pages in a collection" option that's now gone. I'm also not able to download single pages, even by right-clicking. I guess I'll email them and ask.
Thanks -- I just checked again, and now I see how to do it in Safari. Previously I was trying to do it from the link and not the page itself. I guess I was confused by the removal of the download button.