jupyterlab/packages/theme-dark-extension/style/fonts.css

/*-----------------------------------------------------------------------------
| Copyright (c) Jupyter Development Team.
| Distributed under the terms of the Modified BSD License.
|----------------------------------------------------------------------------*/

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

@font-face {
  font-family: 'Source Code Pro';
  src: url('fonts/SourceCodePro-Bold.ttf') format('truetype');
  font-weight: 700;
  font-style: normal;
}