Fonts

Add custom fonts

Docs

Hosted fonts

Go to: Panel > Site > External files:

Add URL > https://fonts.googleapis.com/css?family=Roboto:400,400i,700,700i
Add URL > https://fonts.googleapis.com/css?family=Merriweather:400,700

Go to: Panel > Site > Custom CSS:

<style type="text/css">
  :root {
    --font-family-body: "Roboto";
    --font-family-heading: "Merriweather";
  }
</style>

Self-hosted fonts

Upload font files to server: /assets/fonts/

Go to: Panel > Site > Custom CSS:

<style type="text/css">
  /* font declaration */
  @font-face {
    font-family: 'Roboto';
    font-style: normal;
    font-weight: 400;
    src: 
      local('Roboto'),
      local('Roboto-Regular'),
      url('/assets/fonts/roboto/roboto-regular.woff') format('woff'),
      url('/assets/fonts/roboto/roboto-regular.woff2') format('woff2');
  }
  /* font assignment */
  :root {
    --font-family-body: Roboto;
    --font-family-heading: Lora;
  }
</style>

You'll need a @font-face declaration for every style/weight/language in every font
You can alternatively put all @font-face declarations in a css file, upload it to server, then add a link to it via panel
@font-face reference: https://developer.mozilla.org/en-US/docs/Web/CSS/@font-face
@font-face tutorial: https://css-tricks.com/snippets/css/using-font-face