Arial with Miller Display in action on navigatingresponsibly.dk

Under the hood

.header-1 { font-family: MillerDisplay, serif; font-size: 93px; font-style: normal; font-weight: normal; letter-spacing: 1px; line-height: 112px; text-transform: none; color: #020E37; }
.header-2 { font-family: MillerDisplay, serif; font-size: 23px; font-style: normal; font-weight: normal; letter-spacing: 0px; line-height: 32px; text-transform: none; color: #020E37; }
.content-1 { font-family: Arial, sans-serif; font-size: 15px; font-style: normal; font-weight: normal; letter-spacing: 0px; line-height: 30px; text-transform: none; color: #020E37; }
.content-2 { font-family: Arial, sans-serif; font-size: 15px; font-style: normal; font-weight: normal; letter-spacing: 0px; line-height: 30px; text-transform: none; color: #020E37; }

Arial is available from Fonts.com and MyFonts.