Ask HN: How do you keep web pages for further reference?

Lately, I started being much more systematic in how I keep track of what I read [1]. With it came the need to keep a reference to the source. While it is easy for scientific papers (just download the pdf), I struggle with web-based content (blog posts and podcasts, mostly). Keeping the URL is easy but not future proof. Printing to pdf kinda works for blog posts, but you loose links. Saving the html seems messy, and could still break if links to external content (stylesheets, scripts, images) break.

I am surely not the only one to hit this wall. I am curious to hear how others solved this.

[1] I use the Zettelkasten method, discovered recently through HN