Mark with Source Sans Pro in action on getkeepsafe.com

.header-1 { font-family: MarkPro, sans-serif; font-size: 39.3995px; font-style: normal; font-weight: 700; letter-spacing: normal; line-height: 47.2794px; text-transform: none; color: #371989; }
.header-2 { font-family: "Source Sans Pro", sans-serif; font-size: 17.5109px; font-style: normal; font-weight: 500; letter-spacing: normal; line-height: 21.8886px; text-transform: none; color: #371989; }
.content-1 { font-family: "Source Sans Pro", sans-serif; font-size: 15.7598px; font-style: normal; font-weight: 100; letter-spacing: 0.787989px; line-height: 20.1375px; text-transform: none; color: #2E2E2E; }
.content-2 { font-family: "Source Sans Pro", sans-serif; font-size: 21.0131px; font-style: normal; font-weight: 100; letter-spacing: 1.05065px; line-height: 26.2663px; text-transform: none; color: #371989; }
Source Sans Pro is available from Font Squirrel, Google Web Fonts and Typekit.

Try this combination out in Pair and Compare.
Found by @mikesten on 15 Dec 2018.

Liked by:
@mikesten @Joshua_D_

Mark with Source Sans Pro