Examples of websites using
PT Serif
(PT Serif is a serif font designed by ParaType. The font family consists of multiple styles, including regular and italic, and is suitable for various projects)
with
Untitled Sans
(Untitled Sans is a sans-serif font designed by Klim Type Foundry and released in 2017. The font family consists of 10 styles, including regular and italic styles, available in various weights and widths)