Replace explicit z-level checks with defines

code/game/gamemodes/nuclear/nuclear_challenge.dm

@@ -67,7 +67,7 @@
 	if(GLOB.player_list.len < CHALLENGE_MIN_PLAYERS)
 		to_chat(user, "The enemy crew is too small to be worth declaring war on.")
 		return FALSE
-	if(user.z != ZLEVEL_CENTCOM)
+	if(!user.onSyndieBase())
 		to_chat(user, "You have to be at your base to use this.")
 		return FALSE
 	if(world.time-SSticker.round_start_time > CHALLENGE_TIME_LIMIT)

code/game/gamemodes/nuclear/nuclearbomb.dm

@@ -451,12 +451,12 @@
 	var/off_station = 0
 	var/turf/bomb_location = get_turf(src)
 	var/area/A = get_area(bomb_location)
-	if(bomb_location && (bomb_location.z in GLOB.station_z_levels))
+	if(bomb_location && is_station_level(bomb_location.z))
 		if(istype(A, /area/space))
 			off_station = NUKE_NEAR_MISS
 		if((bomb_location.x < (128-NUKERANGE)) || (bomb_location.x > (128+NUKERANGE)) || (bomb_location.y < (128-NUKERANGE)) || (bomb_location.y > (128+NUKERANGE)))
 			off_station = NUKE_NEAR_MISS
-	else if((istype(A, /area/syndicate_mothership) || (istype(A, /area/shuttle/syndicate)) && bomb_location.z == ZLEVEL_CENTCOM))
+	else if(bomb_location.onSyndieBase())
 		off_station = NUKE_SYNDICATE_BASE
 	else
 		off_station = NUKE_MISS_STATION
@@ -556,7 +556,7 @@ This is here to make the tiles around the station mininuke change when it's arme
 		addtimer(CALLBACK(user, /atom/proc/add_atom_colour, (i % 2)? "#00FF00" : "#FF0000", ADMIN_COLOUR_PRIORITY), i)
 	addtimer(CALLBACK(src, .proc/manual_suicide, user), 101)
 	return MANUAL_SUICIDE
-	
+
 /obj/item/disk/proc/manual_suicide(mob/living/user)
 	user.remove_atom_colour(ADMIN_COLOUR_PRIORITY)
 	user.visible_message("<span class='suicide'>[user] was destroyed by the nuclear blast!</span>")