Add local sources

[tracker1]

Prefix local variants of fonts...

  src: local('Roboto),
       local('Roboto Regular'),
       local('Roboto-Regular'),
       url('....'),
       ...

Example from inconsolata-fontface as a reference...

@font-face {
  font-family: 'Inconsolata';
  font-display: auto;
  src: local('Inconsolata'),
       local('Inconsolata Bold'),
       local('Inconsolata-Bold'),
       url('fonts/Inconsolata-Bold.woff2') format('woff2'),
       url('fonts/Inconsolata-Bold.woff') format('woff');
  font-weight: bold;
  font-style: normal;
}