Examples of websites using
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)
with
Acier
(designed by Adolphe Mouron Cassandre and Jean-Baptiste Levée and released by Deberny & Peignot in 1930)