### Default Fonts

xaringanthemer by default uses a different set of default fonts for heading and body fonts. The new defaults use Cabin for headings and Noto Sans for body text. These fonts are easier to read on screens and at a distance during presentations, and they support a wide variety of languages and weights. Another reason for the change is that the xaringan (remarkjs) default body font, Droid Serif, is no longer officially included in Google Fonts.

If you would like to use the fonts from the default xaringan theme, you can use the following arguments in your style function.

    style_xaringan(
      text_font_family = "Droid Serif",
      text_font_url = "https://fonts.googleapis.com/css?family=Droid+Serif:400,700,400italic",
      header_font_google = google_font("Yanone Kaffeesatz")
    )

### Custom and Google Font Fonts

xaringanthemer makes it easy to use Google Fonts in your presentations (provided you have an internet connection during the presentation) or to fully specify your font files.

To use Google Fonts, set the `<type>_font_google` theme arguments – `text_font_google`, `header_font_google`, `code_font_google` — using the `google_font()` helper. The help documentation in `?google_font` provides more info.

    style_mono_light(
      header_font_google = google_font("Josefin Slab", "600"),
      text_font_google   = google_font("Work Sans", "300", "300i"),
      code_font_google   = google_font("IBM Plex Mono")
    )

If you set an `<type>_font_google` theme arguments, then `<type>_font_family`, `<type>_font_weight` and `<type>_font_url` are overwritten – where `<type>` is one of `header`, `text`, or `code`.

To use a font hosted outside of Google fonts, you need to provide both `<type>_font_family` and `<type>_font_url`. For example, suppose you want to use a code font with ligatures for your code chunks, such as Fira Code, which would be declared with `code_font_family`. The browser usage section of the Fira Code README provides a CSS URL to be used with an `@import` statement that you can use with the `code_font_url` argument.

    style_solarized_dark(
      code_font_family = "Fira Code",
      code_font_url = "https://cdn.jsdelivr.net/gh/tonsky/FiraCode@2/distr/fira_code.css"
    )

Remember that you need to supply either `<type>_google_font` using the `google_font()` helper or both `<type>_font_family` and `<type>_font_url`.

### Using Additional Fonts

If you want to use additional fonts for use in custom CSS definitions, use the `extra_fonts` argument to pass a list of URLs or `google_font()`s. Notice that you will need to add custom CSS (for example, via `extra_css`) to use the fonts imported in `extra_fonts`.

    style_mono_light(
      extra_fonts = list(
        google_font("Sofia"),
        # Young Serif by uplaod.fr
        "https://cdn.jsdelivr.net/gh/uplaod/YoungSerif/fonts/webfonts/fontface.css",
      ),
      extra_css = list(
        ".title-slide h2" = list("font-family" = "Sofia"),
        blockquote = list("font-family" = "youngserifregular")
      )
    )