Proxima Nova in action on circleci.com

Under the hood

.header-1 { font-family: ProximaNova, "Helvetica Neue", Helvetica, Arial, sans-serif; font-size: 52px; font-style: normal; font-weight: 300; letter-spacing: normal; line-height: 78px; text-transform: none; color: #212121; }
.header-2 { font-family: ProximaNova, "Helvetica Neue", Helvetica, Arial, sans-serif; font-size: 20px; font-style: normal; font-weight: 300; letter-spacing: normal; line-height: 30px; text-transform: none; color: #555555; }
.content-1 { font-family: ProximaNova, "Helvetica Neue", Helvetica, Arial, sans-serif; font-size: 16px; font-style: normal; font-weight: bold; letter-spacing: 1px; line-height: 24px; text-transform: capitalize; color: #FFFFFF; }