metamask-extension/ui/app/css/itcss/settings/typography.scss

@import url('https://fonts.googleapis.com/css?family=Roboto:300,500');

@import url('https://maxcdn.bootstrapcdn.com/font-awesome/4.4.0/css/font-awesome.min.css');

@font-face {
  font-family: 'Montserrat Regular';
  src: url('/fonts/Montserrat/Montserrat-Regular.woff') format('woff');
  src: url('/fonts/Montserrat/Montserrat-Regular.ttf') format('truetype');
  font-weight: 400;
  font-style: normal;
  font-size: 'small';
}

@font-face {
  font-family: 'Montserrat Bold';
  src: url('/fonts/Montserrat/Montserrat-Bold.woff') format('woff');
  src: url('/fonts/Montserrat/Montserrat-Bold.ttf') format('truetype');
  font-weight: 400;
  font-style: normal;
}

@font-face {
  font-family: 'Montserrat Light';
  src: url('/fonts/Montserrat/Montserrat-Light.woff') format('woff');
  src: url('/fonts/Montserrat/Montserrat-Light.ttf') format('truetype');
  font-weight: 400;
  font-style: normal;
}

@font-face {
  font-family: 'Montserrat UltraLight';
  src: url('/fonts/Montserrat/Montserrat-UltraLight.woff') format('woff');
  src: url('/fonts/Montserrat/Montserrat-UltraLight.ttf') format('truetype');
  font-weight: 400;
  font-style: normal;
}

@font-face {
  font-family: 'DIN OT';
  src: url('/fonts/DIN_OT/DINOT-2.otf') format('opentype');
  font-weight: 400;
  font-style: normal;
}

@font-face {
  font-family: 'DIN OT Light';
  src: url('/fonts/DIN_OT/DINOT-2.otf') format('opentype');
  font-weight: 200;
  font-style: normal;
}

@font-face {
  font-family: 'DIN NEXT';
  src: url('/fonts/DIN NEXT/DIN NEXT W01 Regular.otf') format('opentype');
  font-weight: 400;
  font-style: normal;
}

@font-face {
  font-family: 'DIN NEXT Light';
  src: url('/fonts/DIN NEXT/DIN NEXT W10 Light.otf') format('opentype');
  font-weight: 400;
  font-style: normal;
}

@font-face {
  font-family: 'Lato';
  src: url('/fonts/Lato/Lato-Regular.ttf') format('truetype');
  font-weight: 400;
  font-style: normal;
}