here's an example of font usage:

;-- colors --------------------------------------------------------------------;

(def grey-fg (rgb 0xF5F5F5))
(def grey-bg (rgb 0xDDDDDD))
(def black   (rgb 0x3F3F3F))

;-- typography ----------------------------------------------------------------;

(def lato-medium (font :system ["Lato Medium"]           :truetype "lato-medium.ttf"            :generic :sans-serif))
(def monospace   (font :system ["Souce Code Pro Medium"] :opentype "source-code-pro-medium.otf" :generic :monospace))

(def +label+ {:t 14 :tf lato-medium :tc black})
(def +code+  {:t 16 :tf monospace   :tc black})

(elem +code+ :sh (r 1 1) :c grey-bg :b 2 :bc grey-fg
  "console.log(\"hello world\");")