System Fonts in action on designcode.io

Under the hood

.header-1 { font-family: -apple-system, system-ui, Helvetica, Roboto; font-size: 104px; font-style: normal; font-weight: 400; letter-spacing: normal; line-height: 135px; text-transform: none; color: #FFFFFF; }
.header-2 { font-family: -apple-system, system-ui, Helvetica, Roboto; font-size: 104px; font-style: normal; font-weight: 700; letter-spacing: normal; line-height: 135px; text-transform: none; color: #FFFFFF; }
.content-1 { font-family: -apple-system, system-ui, Helvetica, Roboto; font-size: 19px; font-style: normal; font-weight: 500; letter-spacing: normal; line-height: 24px; text-transform: none; color: #FFFFFF; }
.content-2 { font-family: -apple-system, system-ui, Helvetica, Roboto; font-size: 24px; font-style: normal; font-weight: 600; letter-spacing: normal; line-height: 32px; text-transform: none; color: #FFFFFF; }
.content-3 { font-family: -apple-system, system-ui, Helvetica, Roboto; font-size: 14px; font-style: normal; font-weight: 500; letter-spacing: normal; line-height: 16px; text-transform: none; color: #FFFFFF; }
.content-4 { font-family: -apple-system, system-ui, Helvetica, Roboto; font-size: 20px; font-style: normal; font-weight: 700; letter-spacing: normal; line-height: 26px; text-transform: none; color: #FFFFFF; }
.content-5 { font-family: -apple-system, system-ui, Helvetica, Roboto; font-size: 12px; font-style: normal; font-weight: 400; letter-spacing: normal; line-height: 15px; text-transform: none; color: #FFFFFF; }