For the last few months I’ve been using Alexander Rink’s Roam CSS system, which he’s recently released out of beta. The Quattro theme he’s developed is excellent, a look that models the iA Writer app for macOS.

This system has a documented library of variables you can customize. I went in and made a few tweaks to mine for some colors and highlights here and there, but the base is awesome.

Roam theming is pretty easy to set up. I’ve got a number of themes set up that I can toggle between.