Customise Focused (Themes, Fonts, Layout)
Change the theme, typeface, font-size, and line-length in Focused by adjusting the options available in the Fonts menu (Command-T).
To customise Focused's writing view, move the cursor to the left of the window to show the sidebar, and press the Fonts button (as shown below).
Focused comes with three themes, six different choices of typeface, and three individual settings for both font-size and line-length.
Focused automatically adjusts the font-size and line-length when the Responsive Layout option is enabled.