[OSM-dev] Questions on modifying openstreetmap-carto

[ika-chan! (OpenStreetMap)]

Hello,

I have made significant progress in creating a tutorial for a fantasy map server on the wiki, having gone as far as getting Nominatim and its UI working last night.

Now, I am moving my focus to modding OpenStreetMap Carto, and I know a few very basic modifications, like recolouring existing features (see https://wiki.openstreetmap.org/wiki/User:Ika-chan!/British_road_colours). However, I would like to expand on mere recolouring and ask how I can modify OpenStreetMap Carto to:

1. Render “railway=rail” in a different colour when “highspeed=yes”.
2. Render “railway=station” in a different icon when the key “network” contains a certain value or a combination of certain values like (but not exclusively) “National Rail” or “TfL Rail”.

I am still new to OpenStreetMap Carto’s language: I assume that the developers use a text editor for all the rendering rules?

Best,

— ika-chan!