This website is hosted by the very capable folks at Squarespace. The customized design is a takeoff of the Native template.
The text for the sub-title, navigation menu, and header are set in the Raleway typeface, which was designed by Matt McInerney as part of the League of Moveable Type, an open source typography website.
Raleway is an elegant sans-serif typeface, designed in a single thin weight. It is a display face that features both old style and lining numerals, standard and discretionary ligatures, a pretty complete set of diacritics, as well as a stylistic alternate inspired by more geometric sans-serif typefaces than its neo-grotesque inspired default character set.