Examples of websites using
Circular
(Circular is a geometric sans-serif font designed by Laurenz Brunner and released by Lineto. The family consists of 6 weights with matching italics, totaling to 12 styles available)
with
Avenir
(Avenir is a sans-serif font designed by Adrian Frutiger and Nadine Chahine, released by Linotype in 1988. It features clean and modern letterforms and is available in multiple weights and styles)