Avenir with Helvetica Neue in action on rampsapp.com

Under the hood

.header-1 { font-family: avenir, 'helvetica neue'; font-size: 40px; font-style: normal; font-weight: bold; letter-spacing: normal; line-height: normal; text-transform: none; color: #909090; }
.header-2 { font-family: 'helvetica neue'; font-size: 19px; font-style: normal; font-weight: normal; letter-spacing: normal; line-height: 32px; text-transform: none; color: #909090; }