Starter style for libraries using Mapbox style language like: Mapbox GL JS and Maplibre GL JS.
Wrote it down for myself when I want to set up a map for non-commercial OpenStreetMap-related purposes and don't want to use commercially available vector tiles.
It contains just OSM raster tiles (make sure usage won't be against tiles usage policy).
It can be loaded into visual editor such as Mapbox Studio or Maputnik.