This is a royal pain in the ass.
Your options, judging from what I’ve seen:
- Buy HTMLDOC or download and compile v1.9 (unstable), which (supposedly) works with CSS.
- Download HTML2PS, which doesn’t work with CSS.
- Buy DA and set up an automator workflow that opens all HTML files and then exports them as PDF and then drag them into your database.
- Get used to clicking a whole lot.