The recommended font is Monaco
font-family: Monaco, Consolas, Menlo, monospace and UI theme https://atom.io/themes/pristine-ui
You can install Fleko Syntax via Atom in
Preferences > Install (themes tab) and search for Fleko Syntax
Or via command line
$ apm install fleko-syntax
Good catch. Let us know what about this package looks wrong to you, and we'll investigate right away.