How can I import HTML into an iWork Pages document?

Question

I'm working on an ebook that I'm writing as plain text/Markdown. I converted that into HTML and would like to import the generated HTML document into a Pages document to do the final formatting.

I created a Pages template and defined styles for headings, lists, etc. However, when I copy/paste the HTML file from Safari into Pages, the paragraph styles are lost. E.g. headings in the HTML document are just bold text in the Pages document.

Edit > Paste and Match Styles does not work either as this removes all formatting.

It seems such an easy task, get the structured text, HTML, into the Pages document and have headings and lists remain headings and lists.

Any ideas would be appreciated! Thanks!