diff --git a/scripts/ui/login_screen.gd b/scripts/ui/login_screen.gd
index 79ec3cd..e738762 100644
--- a/scripts/ui/login_screen.gd
+++ b/scripts/ui/login_screen.gd
@@ -42,7 +42,9 @@ var poll_timer: Timer
 var mode := "login"
 var reset_requested := false
 var steam_transaction_id := ""
-var steam_poll_attempts := 0
+var steam_poll_deadline_msec := 0
+var steam_poll_failures := 0
+var steam_popup_opened := false
 var automatic_login_pending := false
 var login_attempt_username := ""
 var compact_layout := false
@@ -73,6 +75,7 @@ func _ready() -> void:
 
 
 func on_show(payload: Variant = null) -> void:
+	_reset_steam_flow()
 	_set_busy(false)
 	_set_mode("login")
 	_clear_message()
@@ -84,7 +87,7 @@ func on_show(payload: Variant = null) -> void:
 
 
 func on_hide() -> void:
-	poll_timer.stop()
+	_reset_steam_flow()
 
 
 func _build_ui() -> void:
@@ -407,6 +410,8 @@ func _add_dot_grid(origin: Vector2) -> void:
 
 
 func _set_mode(next_mode: String) -> void:
+	if mode == "steam" and next_mode != "steam":
+		_reset_steam_flow()
 	mode = next_mode
 	if login_view == null: return
 	login_view.visible = mode == "login"
@@ -601,23 +606,30 @@ func _on_reset_confirmed(result: int, code: int, _headers: PackedStringArray, bo
 
 func _start_steam() -> void:
 	if OS.has_feature("web"):
-		JavaScriptBridge.eval("window.medmindSteamWindow = window.open('about:blank', 'medmind_steam');", true)
+		var popup_result: Variant = JavaScriptBridge.eval("window.ranazeSteamWindow = window.open('about:blank', 'ranaze_steam'); window.ranazeSteamWindow !== null;", true)
+		steam_popup_opened = bool(popup_result)
+		if not steam_popup_opened:
+			return _show_error("Steam sign in needs a popup. Allow popups for this site, then try again.")
 	_send_json("steam_start", "/steam/start", {}, "Opening Steam...")
 
 
 func _on_steam_started(result: int, code: int, _headers: PackedStringArray, body: PackedByteArray) -> void:
 	_set_busy(false)
 	if result != HTTPRequest.RESULT_SUCCESS or code < 200 or code >= 300:
+		_close_steam_popup()
 		return _show_error("Unable to start Steam sign in.")
 	var data := _parse_dictionary(body)
 	steam_transaction_id = str(data.get("transactionId", ""))
 	var auth_url := str(data.get("authUrl", ""))
-	if steam_transaction_id.is_empty() or auth_url.is_empty(): return _show_error("Steam returned an invalid sign-in response.")
+	if steam_transaction_id.is_empty() or auth_url.is_empty():
+		_close_steam_popup()
+		return _show_error("Steam returned an invalid sign-in response.")
 	if OS.has_feature("web"):
-		JavaScriptBridge.eval("if (window.medmindSteamWindow) { window.medmindSteamWindow.location.href = %s; } else { window.location.href = %s; }" % [JSON.stringify(auth_url), JSON.stringify(auth_url)], true)
+		JavaScriptBridge.eval("if (window.ranazeSteamWindow && !window.ranazeSteamWindow.closed) { window.ranazeSteamWindow.location.href = %s; }" % JSON.stringify(auth_url), true)
 	else:
 		OS.shell_open(auth_url)
-	steam_poll_attempts = 0
+	steam_poll_deadline_msec = Time.get_ticks_msec() + 300000
+	steam_poll_failures = 0
 	_show_success("Complete sign in in the Steam window. Waiting for verification...")
 	poll_timer.start()
 
@@ -625,21 +637,32 @@ func _on_steam_started(result: int, code: int, _headers: PackedStringArray, body
 func _poll_steam() -> void:
 	var status_request: HTTPRequest = requests["steam_status"]
 	if steam_transaction_id.is_empty() or status_request.get_http_client_status() != HTTPClient.STATUS_DISCONNECTED: return
-	steam_poll_attempts += 1
-	if steam_poll_attempts > 150:
-		poll_timer.stop(); return _show_error("Steam sign in timed out. Try again when ready.")
+	if steam_poll_deadline_msec > 0 and Time.get_ticks_msec() >= steam_poll_deadline_msec:
+		_reset_steam_flow()
+		return _show_error("Steam sign in timed out. Try again when ready.")
 	var error: Error = status_request.request("%s/steam/status/%s" % [auth_base_url, steam_transaction_id])
-	if error != OK: _show_error("Waiting for a stable connection to Steam...")
+	if error != OK:
+		steam_poll_failures += 1
+		if steam_poll_failures >= 3: _show_error("Connection interrupted. Still waiting for Steam...")
 
 
 func _on_steam_status(result: int, code: int, _headers: PackedStringArray, body: PackedByteArray) -> void:
-	if result != HTTPRequest.RESULT_SUCCESS or code >= 500: return
+	if result != HTTPRequest.RESULT_SUCCESS or code >= 500 or code == 429:
+		steam_poll_failures += 1
+		if steam_poll_failures >= 3: _show_error("Connection interrupted. Still waiting for Steam...")
+		return
 	if code == 404:
-		poll_timer.stop(); return _show_error("Steam sign in expired. Please try again.")
+		_reset_steam_flow()
+		return _show_error("Steam sign in expired. Please try again.")
+	if code < 200 or code >= 300:
+		_reset_steam_flow()
+		return _show_error(_response_message(body, "Steam sign in could not be completed."))
+	steam_poll_failures = 0
 	var data := _parse_dictionary(body)
 	match str(data.get("status", "pending")):
-		"requires_account": poll_timer.stop(); _set_mode("steam")
-		"complete": poll_timer.stop(); _accept_session(body, str(data.get("username", "")))
+		"pending": _show_success("Complete sign in in the Steam window. Waiting for verification...")
+		"requires_account": poll_timer.stop(); _close_steam_popup(); _set_mode("steam")
+		"complete": poll_timer.stop(); _close_steam_popup(); _accept_session(body, str(data.get("username", "")))
 
 
 func _on_steam_action_changed(index: int) -> void:
@@ -665,11 +688,25 @@ func _on_steam_completed(result: int, code: int, _headers: PackedStringArray, bo
 	_set_busy(false)
 	if result != HTTPRequest.RESULT_SUCCESS or code < 200 or code >= 300:
 		return _show_error(_response_message(body, "Unable to connect this Steam account."))
-	steam_poll_attempts = 0
+	steam_poll_failures = 0
 	poll_timer.start()
 	_poll_steam()
 
 
+func _reset_steam_flow() -> void:
+	if poll_timer != null: poll_timer.stop()
+	steam_transaction_id = ""
+	steam_poll_deadline_msec = 0
+	steam_poll_failures = 0
+	_close_steam_popup()
+
+
+func _close_steam_popup() -> void:
+	if OS.has_feature("web") and steam_popup_opened:
+		JavaScriptBridge.eval("if (window.ranazeSteamWindow && !window.ranazeSteamWindow.closed) { window.ranazeSteamWindow.close(); } window.ranazeSteamWindow = null;", true)
+	steam_popup_opened = false
+
+
 func _accept_session(body: PackedByteArray, fallback_username: String) -> void:
 	var response := _parse_dictionary(body)
 	var token := str(response.get("accessToken", ""))
diff --git a/tests/steam_login_test.gd b/tests/steam_login_test.gd
new file mode 100644
index 0000000..7dda5c8
--- /dev/null
+++ b/tests/steam_login_test.gd
@@ -0,0 +1,54 @@
+extends SceneTree
+
+var failures := 0
+var login: Control
+
+
+func _initialize() -> void:
+	call_deferred("_run")
+
+
+func _run() -> void:
+	login = load("res://scripts/ui/login_screen.gd").new()
+	root.add_child(login)
+	await process_frame
+	_test_elapsed_timeout_clears_flow()
+	_test_transient_failure_keeps_transaction()
+	_test_leaving_completion_cancels_flow()
+	login.queue_free()
+	await process_frame
+	quit(1 if failures > 0 else 0)
+
+
+func _test_elapsed_timeout_clears_flow() -> void:
+	login.steam_transaction_id = "expired-transaction"
+	login.steam_poll_deadline_msec = 1
+	login.poll_timer.start()
+	login._poll_steam()
+	_assert(login.steam_transaction_id.is_empty(), "elapsed Steam login deadline should clear the transaction")
+	_assert(login.poll_timer.is_stopped(), "elapsed Steam login deadline should stop polling")
+
+
+func _test_transient_failure_keeps_transaction() -> void:
+	login.steam_transaction_id = "retry-transaction"
+	login.steam_poll_deadline_msec = Time.get_ticks_msec() + 300000
+	login.steam_poll_failures = 2
+	login._on_steam_status(HTTPRequest.RESULT_CANT_CONNECT, 0, PackedStringArray(), PackedByteArray())
+	_assert(login.steam_transaction_id == "retry-transaction", "temporary connection failures should preserve the Steam transaction")
+	_assert(login.steam_poll_failures == 3, "temporary connection failures should be tracked without consuming the deadline")
+
+
+func _test_leaving_completion_cancels_flow() -> void:
+	login.mode = "steam"
+	login.steam_transaction_id = "cancel-transaction"
+	login.poll_timer.start()
+	login._set_mode("login")
+	_assert(login.steam_transaction_id.is_empty(), "leaving Steam account completion should clear its transaction")
+	_assert(login.poll_timer.is_stopped(), "leaving Steam account completion should stop polling")
+
+
+func _assert(condition: bool, message: String) -> void:
+	if condition:
+		return
+	failures += 1
+	push_error(message)
diff --git a/tests/steam_login_test.gd.uid b/tests/steam_login_test.gd.uid
new file mode 100644
index 0000000..4cc9978
--- /dev/null
+++ b/tests/steam_login_test.gd.uid
@@ -0,0 +1 @@
+uid://cnqc7wymmiwdd