How do I interact with CSS maps?

I’ve had ideas floating in my head for awhile about making a gamemode that uses counter-strike maps. I’m pretty mediocre at scripting so I think it would be good practice for me. I’ve made a basic gamemode with custom weapons and teams (probably not implemented right though) before so I’m not a total noob. But one issue I’m having is finding information on Counter-Strike map implementation. I’ve tried various google queries, but all I can find are tutorials for getting CSS content in Garry’s Mod. Where would be a good place to find this information?

To be more specific, I’m looking how to use up team-specific spawns and team-specific doors and effects. For example, some custom CSS maps have player filters where only one team can pass. Basically, how can I tell the source engine that this player is on this team?

If I recall correctly, you have to set the teams’ spawn point types to info_player_terrorist and info_player_counterterrorist. A lot of CS:S entities aren’t available in GMod so you’ll have to recreate them, but it does require a lot of Lua and C++ knowledge. You can find the sources here: https://github.com/LestaD/SourceEngine2007/tree/master/se2007/game/shared/cstrike