Having had access to the web from the mid '90s I find it weird to talk about "old" as if it were a unifying style. The accessibility for making a webpage meant that there was a cambrian explosion of different styles.

If by "old" you mean "minimally styled" then there are plenty of sites from that era that were really extravagantly styled, since it was a new medium that many people were exploring. There were also plenty of sites with Java or Flash that were considerably more intrusive than sites today (not to mention the period of time between when someone realized you open as many popups as you wanted and when popup-blocker plugins appeared).

Also, this is probably me getting old, but https://ucjeps.berkeley.edu/ looks quite modern to me.