zammad/app/assets/stylesheets/font.css

@font-face {
  font-family: 'Fira Sans';
  src: url('fonts/FiraSans-Bold.eot');
  src: url('fonts/FiraSans-Bold.woff2') format('woff2'),
     url('fonts/FiraSans-Bold.woff') format('woff'),
     url('fonts/FiraSans-Bold.ttf') format('truetype');
  font-weight: bold;
  font-style: normal;
}

@font-face {
  font-family: 'Fira Sans';
  src: url('fonts/FiraSans-Regular.eot');
  src: url('fonts/FiraSans-Regular.woff2') format('woff2'),
     url('fonts/FiraSans-Regular.woff') format('woff'),
     url('fonts/FiraSans-Regular.ttf') format('truetype');
  font-weight: normal;
  font-style: normal;
}

@font-face {
  font-family: 'Fira Sans';
  src: url('fonts/FiraSans-Medium.eot');
  src: url('fonts/FiraSans-Medium.woff2') format('woff2'),
     url('fonts/FiraSans-Medium.woff') format('woff'),
     url('fonts/FiraSans-Medium.ttf') format('truetype');
  font-weight: 500;
  font-style: normal;
}

@font-face {
  font-family: 'Fira Sans';
  src: url('fonts/FiraSans-Light.eot');
  src: url('fonts/FiraSans-Light.woff2') format('woff2'),
     url('fonts/FiraSans-Light.woff') format('woff'),
     url('fonts/FiraSans-Light.ttf') format('truetype');
  font-weight: 300;
  font-style: normal;
}