Examples of websites using
IBM Plex Sans
(IBM Plex Sans is a Sans Serif font designed by Mike Abbink of Bold Monday. The font family consists of multiple styles and variations, including regular and italics, and is available in a range of weights)
with
Caslon
(Caslon is a serif font designed by Dave Farey and William Caslon and released by ITC in 1725. The font family consists of multiple styles in various weights and matching italics)