Add interactive aircraft scatter hero effect

src/main/java/kst4contest/controller/ChatController.java

@@ -24,6 +24,7 @@ import kst4contest.logic.PriorityCalculator;
 import kst4contest.model.*;
 import kst4contest.test.MockKstServer;
 import kst4contest.utils.PlayAudioUtils;
+import kst4contest.locatorUtils.Location;
 import kst4contest.view.Kst4ContestApplication;
 
 import java.io.*;
@@ -34,6 +35,7 @@ import java.util.function.Predicate;
 
 
 
+
 /**
  * 
  * Central Chat kst4contest.controller. Instantiate only one time per category of kst Chat.
@@ -318,10 +320,8 @@ public class ChatController implements ThreadStatusCallback, PstRotatorEventList
 
 		EnumSet<Band> offered = EnumSet.noneOf(Band.class);
 
-		synchronized (getLst_chatMemberList()) {
+		for (ChatMember cm : findActiveChatMembersByRawCall(callRaw)) {
-			for (ChatMember cm : getLst_chatMemberList()) {
 			if (cm == null || cm.getCallSignRaw() == null) continue;
-				if (!normalizeCallRaw(cm.getCallSignRaw()).equals(callRaw)) continue;
 
 			Map<Band, ChatMember.ActiveFrequencyInfo> map = cm.getKnownActiveBands();
 			if (map == null || map.isEmpty()) continue;
@@ -340,11 +340,9 @@ public class ChatController implements ThreadStatusCallback, PstRotatorEventList
 							+ " freq=" + e.getValue().frequency
 							+ " ageMs=" + age);
 				}
+			}
+		}
 
-
-				}
-			}
-		}
 		return offered;
 	}
 
@@ -356,10 +354,8 @@ public class ChatController implements ThreadStatusCallback, PstRotatorEventList
 
 		EnumSet<Band> worked = EnumSet.noneOf(Band.class);
 
-		synchronized (getLst_chatMemberList()) {
+		for (ChatMember cm : findActiveChatMembersByRawCall(callRaw)) {
-			for (ChatMember cm : getLst_chatMemberList()) {
 			if (cm == null || cm.getCallSignRaw() == null) continue;
-				if (!normalizeCallRaw(cm.getCallSignRaw()).equals(callRaw)) continue;
 
 			if (cm.isWorked144())  worked.add(Band.B_144);
 			if (cm.isWorked432())  worked.add(Band.B_432);
@@ -368,9 +364,9 @@ public class ChatController implements ThreadStatusCallback, PstRotatorEventList
 			if (cm.isWorked3400()) worked.add(Band.B_3400);
 			if (cm.isWorked5600()) worked.add(Band.B_5760);
 			if (cm.isWorked10G())  worked.add(Band.B_10G);
-				if (cm.isWorked24G())  worked.add(Band.B_24G); // optional, only if your Band enum supports it
+			if (cm.isWorked24G())  worked.add(Band.B_24G);
-			}
 		}
+
 		return worked;
 	}
 
@@ -645,7 +641,8 @@ public class ChatController implements ThreadStatusCallback, PstRotatorEventList
 
 //            rotatorClient.
 
-			this.lst_chatMemberList.clear();;
+//			this.lst_chatMemberList.clear();;
+			this.clearActiveChatMembers();
 			this.lst_clusterMemberList.clear();
 
 			this.setDisconnected(true);
@@ -713,7 +710,7 @@ public class ChatController implements ThreadStatusCallback, PstRotatorEventList
 			}
 		} else if (action.equals(ApplicationConstants.DISCSTRING_DISCONNECTONLY)){
 
-			this.lst_chatMemberList.clear();;
+			this.clearActiveChatMembers();
 			this.lst_clusterMemberList.clear();
 
 
@@ -959,16 +956,9 @@ public class ChatController implements ThreadStatusCallback, PstRotatorEventList
 		if (targetCallsignRaw == null || targetCallsignRaw.isBlank()) {
 			return null;
 		}
-		String normalizedTargetCall = normalizeCallRaw(targetCallsignRaw);
+
-		synchronized (getLst_chatMemberList()) {
+		List<ChatMember> matchingMembers = findActiveChatMembersByRawCall(targetCallsignRaw);
-			for (ChatMember member : getLst_chatMemberList()) {
+		return matchingMembers.isEmpty() ? null : matchingMembers.get(0);
-				if (member == null || member.getCallSignRaw() == null) continue;
-				if (normalizeCallRaw(member.getCallSignRaw()).equals(normalizedTargetCall)) {
-					return member;
-				}
-			}
-		}
-		return null;
 	}
 
 	private String resolveSkedTargetLocator(String targetCallsignRaw) {
@@ -976,22 +966,43 @@ public class ChatController implements ThreadStatusCallback, PstRotatorEventList
 			return null;
 		}
 
-		String normalizedTargetCall = normalizeCallRaw(targetCallsignRaw);
+		for (ChatMember member : findActiveChatMembersByRawCall(targetCallsignRaw)) {
-		synchronized (getLst_chatMemberList()) {
-			for (ChatMember member : getLst_chatMemberList()) {
-				if (member == null || member.getCallSignRaw() == null) continue;
-				if (!normalizeCallRaw(member.getCallSignRaw()).equals(normalizedTargetCall)) continue;
-
 			String locator = member.getQra();
 			if (locator != null && !locator.isBlank()) {
 				return locator.trim().toUpperCase(Locale.ROOT);
 			}
 		}
-		}
 
 		return null;
 	}
 
+//	private ChatMember resolveSkedTargetMember(String targetCallsignRaw) {
+//		if (targetCallsignRaw == null || targetCallsignRaw.isBlank()) {
+//			return null;
+//		}
+//
+//		List<ChatMember> matchingMembers = findActiveChatMembersByRawCall(targetCallsignRaw);
+//		return matchingMembers.isEmpty() ? null : matchingMembers.get(0);
+//
+//	}
+//
+//	private String resolveSkedTargetLocator(String targetCallsignRaw) {
+//		if (targetCallsignRaw == null || targetCallsignRaw.isBlank()) {
+//			return null;
+//		}
+//
+//		String normalizedTargetCall = normalizeCallRaw(targetCallsignRaw);
+//
+//		for (ChatMember member : findActiveChatMembersByRawCall(targetCallsignRaw)) {
+//			String locator = member.getQra();
+//			if (locator != null && !locator.isBlank()) {
+//				return locator.trim().toUpperCase(Locale.ROOT);
+//			}
+//		}
+//
+//		return null;
+//	}
+
 	public StationMetricsService getStationMetricsService() {
 		return stationMetricsService;
 	}
@@ -1014,10 +1025,14 @@ public class ChatController implements ThreadStatusCallback, PstRotatorEventList
 		return new HashMap<>(lastInboundCategoryByCallSignRaw);
 	}
 
+//	public List<ChatMember> snapshotChatMembers() {
+//		synchronized (getLst_chatMemberList()) {
+//			return new ArrayList<>(getLst_chatMemberList());
+//		}
+//	}
+
 	public List<ChatMember> snapshotChatMembers() {
-		synchronized (getLst_chatMemberList()) {
+		return new ArrayList<>(activeChatMembersByCallAndCategory.values());
-			return new ArrayList<>(getLst_chatMemberList());
-		}
 	}
 
 	public List<ContestSked> snapshotActiveSkeds() {
@@ -1126,13 +1141,27 @@ public class ChatController implements ThreadStatusCallback, PstRotatorEventList
 	private ObservableList<ChatMember> chatMemberList = FXCollections.observableArrayList(); // List of active stations
 
 
-	private ObservableList<ChatMember> lst_chatMemberList = FXCollections.synchronizedObservableList(chatMemberList); // List
 																														// of active stn in chat
 	private FilteredList<ChatMember> lst_chatMemberListFiltered = new FilteredList<ChatMember>(chatMemberList);
 	private SortedList<ChatMember> lst_chatMemberSortedFilteredList = new SortedList<ChatMember>(lst_chatMemberListFiltered);
+
+	private ObservableList<ChatMember> lst_chatMemberList = FXCollections.synchronizedObservableList(chatMemberList); // List
 	private ObservableList<Predicate<ChatMember>> lst_chatMemberListFilterPredicates = FXCollections.observableArrayList();
 	private ObservableList<ClusterMessage> lst_clusterMemberList = FXCollections.observableArrayList();
 
+	/*
+	 * Thread-safe active-member model.
+	 *
+	 * MessageBusManagementThread must not use the JavaFX TableView backing list as
+	 * its primary data model. Otherwise every add/remove fires FilteredList,
+	 * SortedList and TableView selection listeners on the MessageBus thread and JavaFX
+	 * can throw "Not on FX application thread" or internal listener NPEs.
+	 *
+	 * This map is the worker-thread safe source of truth. The ObservableList below
+	 * remains a UI mirror and is mutated only on the JavaFX application thread.
+	 */
+	private final java.util.concurrent.ConcurrentMap<String, ChatMember> activeChatMembersByCallAndCategory =
+			new java.util.concurrent.ConcurrentHashMap<>();
 
 	/*
 	 * Message table update buffers.
@@ -1161,6 +1190,254 @@ public class ChatController implements ThreadStatusCallback, PstRotatorEventList
 	// ******************************************************************************************************************************************
 
 
+	/**
+	 * Executes UI-bound work on the JavaFX application thread.
+	 *
+	 * Worker threads may call this safely. If the caller is already on the FX
+	 * thread, the action is executed immediately to preserve ordering.
+	 */
+	private void runOnFxThread(Runnable action) {
+		if (action == null) {
+			return;
+		}
+
+		if (Platform.isFxApplicationThread()) {
+			action.run();
+		} else {
+			Platform.runLater(action);
+		}
+	}
+
+	/**
+	 * Builds the active-member key. The raw/base callsign alone is not enough
+	 * because the same station can be logged into multiple ON4KST categories at
+	 * the same time. Therefore the category number is part of the key.
+	 */
+	private String buildActiveChatMemberKey(String callSign, ChatCategory category) {
+		String normalizedCallsign = ChatMember.normalizeCallSignToBaseCallSign(callSign);
+		if (normalizedCallsign == null || normalizedCallsign.isBlank()) {
+			return null;
+		}
+
+		int categoryNumber = category == null ? -1 : category.getCategoryNumber();
+		return normalizedCallsign.trim().toUpperCase(Locale.ROOT) + "|" + categoryNumber;
+	}
+
+	private String buildActiveChatMemberKey(ChatMember member) {
+		if (member == null) {
+			return null;
+		}
+
+		String callSign = member.getCallSignRaw() != null ? member.getCallSignRaw() : member.getCallSign();
+		return buildActiveChatMemberKey(callSign, member.getChatCategory());
+	}
+
+	/**
+	 * Adds or replaces an active chat member in the worker-thread model and mirrors
+	 * that change to the JavaFX list. This is the only supported path for ON4KST
+	 * user-enter events.
+	 */
+	public void addOrUpdateActiveChatMember(ChatMember member) {
+		String key = buildActiveChatMemberKey(member);
+		if (key == null) {
+			return;
+		}
+
+		activeChatMembersByCallAndCategory.put(key, member);
+
+		runOnFxThread(() -> {
+			int existingIndex = findChatMemberIndexInUiListByKey(key);
+			if (existingIndex >= 0) {
+				lst_chatMemberList.set(existingIndex, member);
+			} else {
+				lst_chatMemberList.add(member);
+			}
+		});
+	}
+
+	/**
+	 * Removes an active chat member from the worker-thread model and from the UI
+	 * mirror. Removal from the ObservableList is always performed on the FX thread
+	 * because the list is bound to FilteredList/SortedList/TableView.
+	 */
+	public boolean removeActiveChatMember(ChatMember member) {
+		String key = buildActiveChatMemberKey(member);
+		if (key == null) {
+			return false;
+		}
+
+		ChatMember removedMember = activeChatMembersByCallAndCategory.remove(key);
+		runOnFxThread(() -> lst_chatMemberList.removeIf(currentMember -> key.equals(buildActiveChatMemberKey(currentMember))));
+		return removedMember != null;
+	}
+
+	/**
+	 * Clears the active-member model and the JavaFX UI mirror. Use this instead of
+	 * getLst_chatMemberList().clear() from timers or worker threads.
+	 */
+	public void clearActiveChatMembers() {
+		activeChatMembersByCallAndCategory.clear();
+		runOnFxThread(() -> lst_chatMemberList.clear());
+	}
+
+	/**
+	 * Resolves a member from the thread-safe active model. This avoids reading the
+	 * TableView backing list from MessageBusManagementThread.
+	 */
+	public ChatMember findActiveChatMember(ChatMember lookForThis) {
+		String key = buildActiveChatMemberKey(lookForThis);
+		return key == null ? null : activeChatMembersByCallAndCategory.get(key);
+	}
+
+	public ChatMember findActiveChatMember(String callSign, ChatCategory category) {
+		String key = buildActiveChatMemberKey(callSign, category);
+		return key == null ? null : activeChatMembersByCallAndCategory.get(key);
+	}
+
+	public int getActiveChatMemberCount() {
+		return activeChatMembersByCallAndCategory.size();
+	}
+
+	/**
+	 * Returns all active category variants of a callsign. This is used when a QRG or
+	 * band hint should be propagated from one category instance to the same station
+	 * in another category.
+	 */
+	public List<ChatMember> findActiveChatMembersByRawCall(String callSignRaw) {
+		String normalizedCallsign = ChatMember.normalizeCallSignToBaseCallSign(callSignRaw);
+		if (normalizedCallsign == null || normalizedCallsign.isBlank()) {
+			return Collections.emptyList();
+		}
+
+		String normalizedKeyPart = normalizedCallsign.trim().toUpperCase(Locale.ROOT);
+		List<ChatMember> matchingMembers = new ArrayList<>();
+
+		for (ChatMember member : activeChatMembersByCallAndCategory.values()) {
+			if (member == null) {
+				continue;
+			}
+
+			String memberCall = member.getCallSignRaw() != null ? member.getCallSignRaw() : member.getCallSign();
+			String normalizedMemberCall = ChatMember.normalizeCallSignToBaseCallSign(memberCall);
+			if (normalizedMemberCall != null && normalizedMemberCall.equalsIgnoreCase(normalizedKeyPart)) {
+				matchingMembers.add(member);
+			}
+		}
+
+		return matchingMembers;
+	}
+
+	/**
+	 * Updates locator and derived direction values in the active model. The UI list
+	 * contains the same member object, but the user-list refresh is still triggered
+	 * on the JavaFX thread so TableView/map derived displays can repaint safely.
+	 */
+	public boolean updateActiveChatMemberLocator(ChatMember lookupMember, String newLocator) {
+		ChatMember activeMember = findActiveChatMember(lookupMember);
+		if (activeMember == null) {
+			return false;
+		}
+
+		activeMember.setQra(newLocator);
+		activeMember.setQrb(new Location().getDistanceKmByTwoLocatorStrings(chatPreferences.getStn_loginLocatorMainCat(), newLocator));
+		activeMember.setQTFdirection(new Location(chatPreferences.getStn_loginLocatorMainCat()).getBearing(new Location(newLocator)));
+		fireUserListUpdate("Locator changed");
+		return true;
+	}
+
+	public boolean updateActiveChatMemberState(ChatMember lookupMember, int newState) {
+		ChatMember activeMember = findActiveChatMember(lookupMember);
+		if (activeMember == null) {
+			return false;
+		}
+
+		activeMember.setState(newState);
+		fireUserListUpdate("User state changed");
+		return true;
+	}
+
+	/**
+	 * Applies a UM3-style user-info update only to an already active chat member.
+	 *
+	 * ON4KST may send UM3 messages for stations that are not logged into the
+	 * current channel, for example when a user changes locator/profile data on the
+	 * website. Such stations must not be added to the visible chat member list,
+	 * because they cannot be addressed in the channel. Their full information will
+	 * be delivered again with UA0/UA5/UA2 when they actually join.
+	 *
+	 * @return true if an active member was found and updated, false if the UM3
+	 *         information was intentionally ignored.
+	 */
+	public boolean updateActiveChatMemberInfoIfPresent(ChatMember updatedMember) {
+		String key = buildActiveChatMemberKey(updatedMember);
+		if (key == null) {
+			return false;
+		}
+
+		ChatMember activeMember = activeChatMembersByCallAndCategory.get(key);
+		if (activeMember == null) {
+			return false;
+		}
+
+		activeMember.setName(updatedMember.getName());
+		activeMember.setQra(updatedMember.getQra());
+		activeMember.setState(updatedMember.getState());
+		activeMember.setLastActivity(updatedMember.getLastActivity());
+		activeMember.setActivityTimeLastInEpoch(updatedMember.getActivityTimeLastInEpoch());
+		activeMember.setQrb(updatedMember.getQrb());
+		activeMember.setQTFdirection(updatedMember.getQTFdirection());
+		fireUserListUpdate("User info updated");
+		return true;
+	}
+
+	/**
+	 * Backward-compatible wrapper for older call sites. Despite the historic name,
+	 * this method no longer adds unknown UM3 users to the active member model.
+	 */
+	public boolean updateOrAddActiveChatMemberInfo(ChatMember updatedMember) {
+		return updateActiveChatMemberInfoIfPresent(updatedMember);
+	}
+
+	/**
+	 * Stores a newly detected QRG/band on all active category variants of a station.
+	 * The old StringProperty is still set for compatibility with existing TableView
+	 * columns and DXCluster code.
+	 */
+	public void applyDetectedFrequencyToActiveMembers(ChatMember sender, Band detectedBand, double detectedFrequencyMhz) {
+		if (sender == null || detectedBand == null || detectedFrequencyMhz <= 0) {
+			return;
+		}
+
+		String displayFrequency = String.valueOf(detectedFrequencyMhz);
+		String rawCall = sender.getCallSignRaw() != null ? sender.getCallSignRaw() : sender.getCallSign();
+
+		for (ChatMember member : findActiveChatMembersByRawCall(rawCall)) {
+			if (member == null) {
+				continue;
+			}
+			member.addKnownFrequency(detectedBand, detectedFrequencyMhz);
+			member.setFrequency(new SimpleStringProperty(displayFrequency));
+		}
+
+		// Also cover dummy senders that are not in the active model, e.g. [n/a] senders.
+		sender.addKnownFrequency(detectedBand, detectedFrequencyMhz);
+		sender.setFrequency(new SimpleStringProperty(displayFrequency));
+		fireUserListUpdate("Frequency detected");
+	}
+
+	private int findChatMemberIndexInUiListByKey(String key) {
+		if (key == null) {
+			return -1;
+		}
+
+		for (int i = 0; i < lst_chatMemberList.size(); i++) {
+			if (key.equals(buildActiveChatMemberKey(lst_chatMemberList.get(i)))) {
+				return i;
+			}
+		}
+		return -1;
+	}
+
 
 
 
@@ -2011,7 +2288,7 @@ public class ChatController implements ThreadStatusCallback, PstRotatorEventList
 							socket.close();
 							
 							chatController.setConnectedAndLoggedIn(false);
-							chatController.getLst_chatMemberList().clear();
+							chatController.clearActiveChatMembers();
 
 							System.out.println("[Chatcontroller, Warning: ] Socket closed or disconnected");
 						

src/main/java/kst4contest/controller/MessageBusManagementThread.java

@@ -34,9 +34,9 @@ public class MessageBusManagementThread extends Thread {
 	private ThreadStatusCallback callBackToController;
 
 	private PrintWriter writer;
-//	private Socket socket;
+	//	private Socket socket;
 	private ChatController client;
-//	private File fileLogRAW;
+	//	private File fileLogRAW;
 //	private TimerTask userActualizationTask; // Is used as a temporary userout-print
 //	private TimerTask userActualizationTask; //kst4contest.test 4 23001
 	// private boolean serverReady = false; //kst4contest.test 4 23001
@@ -324,31 +324,12 @@ public class MessageBusManagementThread extends Thread {
 			// --- STEP 3: Process Result ---
 			if (finalDetectedBand != null && finalDetectedFrequency > 0) {
 
-				// 1. Store in the new Map (for future context/history)
+				/*
-
+				 * Store the detected QRG in the thread-safe active-member model.
-				sender.addKnownFrequency(finalDetectedBand, finalDetectedFrequency);
+				 * The UI table is only a JavaFX mirror, so the MessageBus must not scan
-				// No automatic full terrain analysis here.
+				 * or mutate getLst_chatMemberList() here.
-				// The frequency is stored for later map/manual reachability requests.
+				 */
-
+				client.applyDetectedFrequencyToActiveMembers(sender, finalDetectedBand, finalDetectedFrequency);
-				//propagate known frequency to all instances of the same callsign (callRaw may exist multiple times)
-				try {
-					ArrayList<Integer> sameCallIdx = client.checkListForChatMemberIndexesByCallSign(sender);
-					for (int idx : sameCallIdx) {
-						ChatMember cm = client.getLst_chatMemberList().get(idx);
-						if (cm != null && cm != sender) {
-							cm.addKnownFrequency(finalDetectedBand, finalDetectedFrequency);
-							// No automatic full terrain analysis here.
-							// Avoids exhausting the online terrain API when many stations mention QRGs.
-						}
-					}
-				} catch (Exception e) {
-					System.out.println("[SmartParser, warning]: failed to propagate known frequency across duplicates: " + e.getMessage());
-				}
-
-
-				// 2. Set the old String-Property for GUI compatibility
-				// We assume standard display format (MHz)
-				sender.setFrequency(new javafx.beans.property.SimpleStringProperty(String.valueOf(finalDetectedFrequency)));
 
 				System.out.println("[SmartParser] Detected for " + sender.getCallSign() + ": " +
 						finalDetectedFrequency + " MHz (" + finalDetectedBand + ") " +
@@ -491,6 +472,92 @@ public class MessageBusManagementThread extends Thread {
 		return -1; // if it´s not found, the method will always end here and return -1
 	}
 
+	/**
+	 * Creates a minimal receiver object for ON4KST broadcast messages.
+	 * Keeping this as an object, not null, protects all downstream chat filters
+	 * and debug logging from null receiver paths.
+	 */
+	private ChatMember createAllReceiver() {
+		ChatMember dummy = new ChatMember();
+		dummy.setCallSign("ALL");
+		dummy.setAirPlaneReflectInfo(new AirPlaneReflectionInfo());
+		return dummy;
+	}
+
+	/**
+	 * Resolves a message sender from the thread-safe active-member model. If a
+	 * CH/CR message arrives before the matching user-enter message, a marked
+	 * fallback sender is used. The returned sender is never null.
+	 */
+	private ChatMember resolveInboundSender(String senderCallSign, ChatCategory category, ChatMessage message) {
+		ChatMember lookup = new ChatMember();
+		lookup.setCallSign(senderCallSign);
+		lookup.setChatCategory(category);
+
+		ChatMember senderObj = this.client.findActiveChatMember(lookup);
+		if (senderObj != null) {
+			senderObj.setActivityTimeLastInEpoch(new Utils4KST().time_generateCurrentEpochTime());
+
+			// Remember the last active category so later outgoing replies can be routed correctly.
+			this.client.rememberLastInboundCategory(senderObj.getCallSignRaw(), senderObj.getChatCategory());
+
+			// Metrics influence priority scoring; process them after message text is known.
+			this.client.getStationMetricsService().onInboundMessage(
+					senderObj.getCallSignRaw(),
+					System.currentTimeMillis(),
+					message == null ? null : message.getMessageText(),
+					this.client.getChatPreferences(),
+					this.client.getChatPreferences().getStn_loginCallSign()
+			);
+
+			this.client.getScoreService().requestRecompute("rx-chat-message");
+			return senderObj;
+		}
+
+		ChatMember fallbackSender = new ChatMember();
+		String myCall = this.client.getChatPreferences().getStn_loginCallSign();
+		if (senderCallSign != null && senderCallSign.equalsIgnoreCase(myCall)) {
+			fallbackSender.setCallSign(myCall);
+		} else {
+			fallbackSender.setCallSign("[n/a]" + senderCallSign);
+		}
+		fallbackSender.setChatCategory(category);
+		fallbackSender.setAirPlaneReflectInfo(new AirPlaneReflectionInfo());
+		return fallbackSender;
+	}
+
+	/**
+	 * Resolves a message receiver from the active-member model. Unknown receivers
+	 * are represented as explicit fallback objects instead of null. This keeps PM
+	 * echo display and historic messages stable even if the target station already
+	 * left the chat.
+	 */
+	private ChatMember resolveInboundReceiver(String receiverCallSign, ChatCategory category) {
+		if (receiverCallSign == null || receiverCallSign.equals("0")) {
+			return createAllReceiver();
+		}
+
+		ChatMember lookup = new ChatMember();
+		lookup.setCallSign(receiverCallSign);
+		lookup.setChatCategory(category);
+
+		ChatMember receiverObj = this.client.findActiveChatMember(lookup);
+		if (receiverObj != null) {
+			return receiverObj;
+		}
+
+		ChatMember fallbackReceiver = new ChatMember();
+		String myCall = this.client.getChatPreferences().getStn_loginCallSign();
+		if (receiverCallSign.equalsIgnoreCase(myCall)) {
+			fallbackReceiver.setCallSign(myCall);
+		} else {
+			fallbackReceiver.setCallSign(receiverCallSign + "(left)");
+		}
+		fallbackReceiver.setChatCategory(category);
+		fallbackReceiver.setAirPlaneReflectInfo(new AirPlaneReflectionInfo());
+		return fallbackReceiver;
+	}
+
 	/**
 	 * Processes received messages via port 23001 (improved telnet Interface)
 	 *
@@ -590,7 +657,7 @@ public class MessageBusManagementThread extends Thread {
 
 
 				if (!client.getChatPreferences().getStn_loginCallSign().equals(newMember.getCallSign())) {
-					this.client.getLst_chatMemberList().add(newMember); //the own call will not be in the list
+					this.client.addOrUpdateActiveChatMember(newMember); // the own call will not be in the list
 //					this.client.getReachabilityService().ensureAutoTropoMarginCalculated(newMember);
 					// Reachability is calculated on demand only: map click, selected station, or manual request.
 				}
@@ -637,7 +704,7 @@ public class MessageBusManagementThread extends Thread {
 
 						newMember = this.client.getDbHandler().fetchChatMemberWkdDataForOnlyOneCallsignFromDB(newMember);
 
-					this.client.getLst_chatMemberList().add(newMember);
+						this.client.addOrUpdateActiveChatMember(newMember);
 //					this.client.getReachabilityService().ensureAutoTropoMarginCalculated(newMember);
 
 						this.client.getDbHandler().storeChatMember(newMember);
@@ -665,17 +732,11 @@ public class MessageBusManagementThread extends Thread {
 						newMember.setCallSign(splittedMessageLine[2]);
 
 						System.out.println("[MSGBUSMGT, Info:] User left Chat and will be removed from list ["
-						+ this.client.getLst_chatMemberList().size() + "] :" + newMember.getCallSign());
+								+ this.client.getActiveChatMemberCount() + "] :" + newMember.getCallSign());
-				try {
-					this.client.getLst_chatMemberList().remove(
-							checkListForChatMemberIndexByCallSign(this.client.getLst_chatMemberList(), newMember));
 
-					//since 1.26 new method design to detect chatcategory, too!
+						if (!this.client.removeActiveChatMember(newMember)) {
-
+							System.out.println("[MSGBUSMGT, Info:] User sent left chat but was not active: "
-				} catch (Exception e) {
+									+ newMember.getCallSign() + " / " + newMember.getChatCategory());
-					System.out.println("[MSGBUSMGT, EXC!, Error:] User sent left chat but had not been there ... ["
-							+ this.client.getLst_chatMemberList().size() + "] :" + newMember.getCallSign() + "\n"
-							+ e.getStackTrace());
 						}
 
 					} else
@@ -695,9 +756,12 @@ public class MessageBusManagementThread extends Thread {
 
 							chategoryForMessageAndMessageSender = newMessageArrived.getChatCategory();
 							newMessageArrived.setMessageGeneratedTime(splittedMessageLine[2]);
+							newMessageArrived.setMessageSenderName(splittedMessageLine[4]);
+							newMessageArrived.setMessageText(splittedMessageLine[6]);
 
 							if (splittedMessageLine[3].equals("SERVER")) {
 								ChatMember dummy = new ChatMember();
+								dummy.setAirPlaneReflectInfo(new AirPlaneReflectionInfo());
 								dummy.setCallSign("SERVER");
 								dummy.setName("Sysop");
 								newMessageArrived.setSender(dummy);
@@ -707,77 +771,16 @@ public class MessageBusManagementThread extends Thread {
 
 							} else {
 
-					ChatMember sender = new ChatMember();
+								newMessageArrived.setSender(resolveInboundSender(
-					sender.setCallSign(splittedMessageLine[3]);
+										splittedMessageLine[3],
-					sender.setChatCategory(chategoryForMessageAndMessageSender);
+										chategoryForMessageAndMessageSender,
-
+										newMessageArrived));
-					int index = checkListForChatMemberIndexByCallSign(this.client.getLst_chatMemberList(), sender);
-
-
-					if (index != -1) {
-						//user not found in the chatmember list
-						try {
-//							newMessageArrived.setSender(this.client.getLst_chatMemberList().get(index)); // set sender to member of
-//							this.client.getLst_chatMemberList().get(index).setActivityTimeLastInEpoch(new Utils4KST().time_generateCurrentEpochTime());
-
-							ChatMember senderObj = this.client.getLst_chatMemberList().get(index);
-							newMessageArrived.setSender(senderObj);
-							senderObj.setActivityTimeLastInEpoch(new Utils4KST().time_generateCurrentEpochTime());
-
-							// Remember last inbound category per callsignRaw (required for correct send-routing later)
-							this.client.rememberLastInboundCategory(senderObj.getCallSignRaw(), senderObj.getChatCategory());
-
-							// Metrics for scoring: momentum, response-time, no-reply, positive signals
-							this.client.getStationMetricsService().onInboundMessage(
-									senderObj.getCallSignRaw(),
-									System.currentTimeMillis(),
-									newMessageArrived.getMessageText(),
-									this.client.getChatPreferences(),
-									this.client.getChatPreferences().getStn_loginCallSign()
-							);
-
-							// Activity/category changes influence priority => request recompute
-							this.client.getScoreService().requestRecompute("rx-chat-message");
-
-						} catch (Exception exc) {
-							ChatMember aSenderDummy = new ChatMember();
-							aSenderDummy.setCallSign(splittedMessageLine[3] + "[n/a]");
-							aSenderDummy.setAirPlaneReflectInfo(new AirPlaneReflectionInfo());
-							newMessageArrived.setSender(aSenderDummy);
-							System.out.println("MsgBusmgtT: Catched Error! " + exc.getMessage() + " // " + splittedMessageLine[3] + " is not in the list! Faking sender!");
-							exc.printStackTrace();
-						}
-																								// b4 init list
-					} else {
-						//user not found in chatmember list, mark it, sender can not be set
-						if (!sender.getCallSign().equals(this.client.getChatPreferences().getStn_loginCallSign().toUpperCase())) {
-							sender.setCallSign("[n/a]" + sender.getCallSign());
-							// if someone sent a message without being in the userlist (cause
-							// on4kst missed implementing....), callsign will be marked
-						} else {
-							//that means, message was by own station, broadcasted to all other
-							ChatMember dummy = new ChatMember();
-							dummy.setCallSign("ALL");
-							newMessageArrived.setReceiver(dummy);
-
-							AirPlaneReflectionInfo preventNullpointerExc = new AirPlaneReflectionInfo();
-							preventNullpointerExc.setAirPlanesReachableCntr(0);
-							sender.setAirPlaneReflectInfo(preventNullpointerExc);
-							newMessageArrived.setSender(sender); //my own call is the sender
-						}
 							}
 
-//					newMessageArrived.setSender(this.client.getChatMemberTable().get(splittedMessageLine[3]));
-				}
-
-				newMessageArrived.setMessageSenderName(splittedMessageLine[4]);
-				newMessageArrived.setMessageText(splittedMessageLine[6]);
 
 							if (splittedMessageLine[7].equals("0")) {
-					// message is not directed to anyone, move it to the cq messages!
+								// message is not directed to anyone, move it to the cq messages.
-					ChatMember dummy = new ChatMember();
+								newMessageArrived.setReceiver(createAllReceiver());
-					dummy.setCallSign("ALL");
-					newMessageArrived.setReceiver(dummy);
 
 								this.client.publishChatMessage(newMessageArrived); // sdtout to all message-List (new from v1.7)
 
@@ -786,36 +789,9 @@ public class MessageBusManagementThread extends Thread {
 							} else {
 								//message is directed to another chatmember, process as such!
 
-					ChatMember receiver = new ChatMember();
+								newMessageArrived.setReceiver(resolveInboundReceiver(
-
+										splittedMessageLine[7],
-					receiver.setChatCategory(chategoryForMessageAndMessageSender); //got out of message itself
+										chategoryForMessageAndMessageSender));
-
-					receiver.setCallSign(splittedMessageLine[7]);
-
-					int index = checkListForChatMemberIndexByCallSign(this.client.getLst_chatMemberList(), receiver);
-
-					if (index != -1) {
-						newMessageArrived.setReceiver(this.client.getLst_chatMemberList().get(index));// -1: Member left Chat
-																								// before...
-					} else { //found in active member list
-
-
-						if (receiver.getCallSign().equals(client.getChatPreferences().getStn_loginCallSign())) {
-							/**
-							 * If mycallsign sent a message to the server, server will publish that message and
-							 * send it to all chatmember including me.
-							 * As mycall is not in the userlist,  the message would not been displayed if I handle
-							 * it in the next case (marking left user, just for information). But I want an echo.
-							 */
-
-							receiver.setCallSign(client.getChatPreferences().getStn_loginCallSign());
-							newMessageArrived.setReceiver(receiver);
-						} else {
-							//this are user which left chat but had been adressed by this message
-							receiver.setCallSign(receiver.getCallSign() + "(left)");
-							newMessageArrived.setReceiver(receiver);
-						}
-					}
 
 //					System.out.println("message directed to: " + newMessageArrived.getReceiver().getCallSign() + ". EQ?: " + this.client.getownChatMemberObject().getCallSign() + " sent by: " + newMessageArrived.getSender().getCallSign().toUpperCase() + " -> EQ?: "+ this.client.getChatPreferences().getLoginCallSign().toUpperCase());
 
@@ -979,7 +955,21 @@ public class MessageBusManagementThread extends Thread {
 										// the "to me message list" with modified messagetext, added rxers callsign
 
 									} else {
-							//message sent to other user
+										/*
+										 * Message sent from one other station to another other station.
+										 *
+										 * The old code reached this point only with members from the visible user list.
+										 * With explicit fallback sender/receiver objects, this path may also see
+										 * stations that already left the chat or arrived before their user-list entry.
+										 * In that case locators may be missing, so angle/range analysis and DX spotting
+										 * must be skipped while the chat message itself is still published.
+										 */
+										boolean senderHasLocator = newMessageArrived.getSender().getQra() != null
+												&& !newMessageArrived.getSender().getQra().isBlank();
+										boolean receiverHasLocator = newMessageArrived.getReceiver().getQra() != null
+												&& !newMessageArrived.getReceiver().getQra().isBlank();
+
+										if (senderHasLocator && receiverHasLocator) {
 											if (DirectionUtils.isInAngleAndRange(client.getChatPreferences().getStn_loginLocatorMainCat(),
 													newMessageArrived.getSender().getQra(),
 													newMessageArrived.getReceiver().getQra(),
@@ -998,7 +988,7 @@ public class MessageBusManagementThread extends Thread {
 												if (client.getChatPreferences().isNotify_dxClusterServerEnabled()) {
 													try {
 														if (newMessageArrived.getSender().getFrequency() != null) {
-                                            //TODO: testing for next version 3.33: addinitional information will be displayed in cluster if there is such an information
+															//TODO: testing for next version 3.33: additional information will be displayed in cluster if there is such information
 															ChatMember onlyForSpottingObject = new ChatMember();
 															onlyForSpottingObject.setCallSign(newMessageArrived.getSender().getCallSign());
 															onlyForSpottingObject.setFrequency(newMessageArrived.getSender().getFrequency());
@@ -1014,11 +1004,10 @@ public class MessageBusManagementThread extends Thread {
 																			newMessageArrived.getSender().getAirPlaneReflectInfo().getRisingAirplanes().get(1).getPotential() + "%");
 																}
 															} else {
-
 																onlyForSpottingObject.setQra(newMessageArrived.getSender().getQra());
 															}
 
-											this.client.getDxClusterServer().broadcastSingleDXClusterEntryToLoggers(onlyForSpottingObject); //tells the DXCluster server to send a DXC message for this member to the logbook software
+															this.client.getDxClusterServer().broadcastSingleDXClusterEntryToLoggers(onlyForSpottingObject);
 														}
 													} catch (Exception exception) {
 														System.out.println("[MSGBUSMGT, ERROR:] DXCluster messageserver error while processing spot for 0: " + newMessageArrived.getSender().getCallSign() + " // " + exception.getMessage());
@@ -1036,14 +1025,21 @@ public class MessageBusManagementThread extends Thread {
 														" ; sender bearing to me: " + new Location(newMessageArrived.getSender().getQra()).getBearing(new Location(client.getChatPreferences().getStn_loginLocatorMainCat())));
 												newMessageArrived.getSender().setInAngleAndRange(false);
 											}
+										} else {
+											newMessageArrived.getSender().setInAngleAndRange(false);
+											System.out.println("[MSGBUSMGT, Info:] Skipping angle/range analysis for message with missing locator: "
+													+ newMessageArrived.getSender().getCallSign() + " -> "
+													+ newMessageArrived.getReceiver().getCallSign());
+										}
 
 //							this.client.getLst_globalChatMessageList().add(0, newMessageArrived);
 										this.client.publishChatMessage(newMessageArrived); // sdtout to all message-List (new from v1.7)
 //						System.out.println("MSGBS bgfx: tx call = " + newMessageArrived.getSender().getCallSign() + " / rx call = " + newMessageArrived.getReceiver().getCallSign());
 									}
 								} catch (NullPointerException referenceDeletedByUserLeftChatDuringMessageprocessing) {
-						System.out.println("MSGBS bgfx, <<<catched error>>>: referenced user left the chat during messageprocessing or message got before user entered chat message: " + referenceDeletedByUserLeftChatDuringMessageprocessing.getStackTrace());
+									System.out.println("MSGBS bgfx, <<<catched error>>>: referenced user left the chat during messageprocessing or message got before user entered chat message: "
-//						referenceDeletedByUserLeftChatDuringMessageprocessing.printStackTrace();
+											+ referenceDeletedByUserLeftChatDuringMessageprocessing.getMessage());
+									referenceDeletedByUserLeftChatDuringMessageprocessing.printStackTrace();
 								}
 
 								// sdtout to me message-List
@@ -1062,7 +1058,8 @@ public class MessageBusManagementThread extends Thread {
 										+ " " + newMessageArrived.getSender().getCallSign() + ", " + newMessageArrived.getMessageSenderName() + " -> "
 										+ newMessageArrived.getReceiver().getCallSign() + ": " + newMessageArrived.getMessageText());
 							} catch (Exception exceptionOccured) {
-					System.out.println("[MSGMgtBus: ERROR CHATCHED ON MAYBE NULL ISSUE]: " + exceptionOccured.getMessage() + "\n" + exceptionOccured.getStackTrace());
+								System.out.println("[MSGMgtBus: ERROR CHATCHED ON MAYBE NULL ISSUE]: " + exceptionOccured.getMessage());
+								exceptionOccured.printStackTrace();
 							}
 
 							// --- Band/QRG recognition (fills ChatMember.knownActiveBands) ---
@@ -1085,24 +1082,21 @@ public class MessageBusManagementThread extends Thread {
 								temp4.setQra(splittedMessageLine[3]);
 								temp4.setLastActivity(new Utils4KST().time_generateActualTimeInDateFormat());
 
-				int index = checkListForChatMemberIndexByCallSign(this.client.getLst_chatMemberList(), temp4);
+								ChatMember foundThisInChatMemberList = this.client.findActiveChatMember(temp4);
-
+								if (foundThisInChatMemberList == null && this.client.getChatCategorySecondChat() != null) {
-				if (index != -1) {
+									/*
+									 * LOC messages do not carry the category. The old implementation checked
+									 * only the main category. Try the second active category as a fallback so
+									 * dual-channel operation can still update locator changes.
+									 */
+									temp4.setChatCategory(this.client.getChatCategorySecondChat());
+									foundThisInChatMemberList = this.client.findActiveChatMember(temp4);
+								}
 
+								if (foundThisInChatMemberList != null) {
 									System.out.println("[MSGBUSMGT:] Locator Change of [" + (splittedMessageLine[2] + "], old was: "
-							+ this.client.getLst_chatMemberList().get(index).getQra() + " new is: "
+											+ foundThisInChatMemberList.getQra() + " new is: " + splittedMessageLine[3]));
-							+ splittedMessageLine[3]));
+									this.client.updateActiveChatMemberLocator(temp4, splittedMessageLine[3]);
-
-					ChatMember foundThisInChatMemberList = this.client.getLst_chatMemberList().get(index); //make less list accesses
-
-//					this.client.getLst_chatMemberList().get(index).setQra(splittedMessageLine[3]);
-//					this.client.getLst_chatMemberList().get(index).setQrb(new Location().getDistanceKmByTwoLocatorStrings(client.getChatPreferences().getLoginLocator(), splittedMessageLine[3]));
-//					this.client.getLst_chatMemberList().get(index).setQTFdirection(new Location(client.getChatPreferences().getLoginLocator()).getBearing(new Location(splittedMessageLine[3])));
-
-					foundThisInChatMemberList.setQra(splittedMessageLine[3]);
-					foundThisInChatMemberList.setQrb(new Location().getDistanceKmByTwoLocatorStrings(client.getChatPreferences().getStn_loginLocatorMainCat(), splittedMessageLine[3]));
-					foundThisInChatMemberList.setQTFdirection(new Location(client.getChatPreferences().getStn_loginLocatorMainCat()).getBearing(new Location(splittedMessageLine[3])));
-
 								} else {
 									System.out.println("[MSGBUSMGT:] ERROR! Locator Change of ["
 											+ (splittedMessageLine[2] + "] is not possible, user is not in the Table!"));
@@ -1232,11 +1226,9 @@ public class MessageBusManagementThread extends Thread {
 
 												stateChangeMember.setChatCategory(util_getChatCategoryByCategoryNrString(splittedMessageLine[1]));
 
-				int index = checkListForChatMemberIndexByCallSign(this.client.getLst_chatMemberList(),
+												if (!this.client.updateActiveChatMemberState(stateChangeMember, stateChangeMember.getState())) {
-						stateChangeMember);
+													System.out.println("[MSGBUSMGT, Info:] State change for inactive user: "
-
+															+ stateChangeMember.getCallSign() + " / " + stateChangeMember.getChatCategory());
-				if (index != -1 && index != 0) {
-					this.client.getLst_chatMemberList().get(index).setState(stateChangeMember.getState());
 												}
 
 //				this.client.getChatMemberTable().get(stateChangeMember.getCallSign())
@@ -1249,31 +1241,43 @@ public class MessageBusManagementThread extends Thread {
 											 */
 												if (splittedMessageLine[0].contains(USERINFOUPDATEORUSERISBACK)) {
 
+													if (splittedMessageLine.length < 6) {
+														System.out.println("[MSGBUSMGT, warning:] Malformed UM3 message ignored: "
+																+ messageToProcess.getMessageText());
+													} else {
 														ChatMember stateChangeMember = new ChatMember();
 
 														stateChangeMember.setChatCategory(util_getChatCategoryByCategoryNrString(splittedMessageLine[1]));
-
 														stateChangeMember.setCallSign(splittedMessageLine[2]);
 														stateChangeMember.setName(splittedMessageLine[3]);
 														stateChangeMember.setQra(splittedMessageLine[4]);
 														stateChangeMember.setState(Integer.parseInt(splittedMessageLine[5]));
 														stateChangeMember.setLastActivity(new Utils4KST().time_generateActualTimeInDateFormat());
-				stateChangeMember.setQrb(new Location().getDistanceKmByTwoLocatorStrings(client.getChatPreferences().getStn_loginLocatorMainCat(), stateChangeMember.getQra()));
+														stateChangeMember.setQrb(new Location().getDistanceKmByTwoLocatorStrings(
-				stateChangeMember.setQTFdirection(new Location(client.getChatPreferences().getStn_loginLocatorMainCat()).getBearing(new Location(stateChangeMember.getQra())));
+																client.getChatPreferences().getStn_loginLocatorMainCat(),
+																stateChangeMember.getQra()));
+														stateChangeMember.setQTFdirection(new Location(client.getChatPreferences().getStn_loginLocatorMainCat())
+																.getBearing(new Location(stateChangeMember.getQra())));
 
-				this.client.getDbHandler().storeChatMember(stateChangeMember); // TODO: not clean, it should be an
+														/*
-																				// upodate
+														 * UM3 is only an info/profile update. ON4KST also sends it for stations
-
+														 * that are not logged into this channel. Such stations must not become
-//					System.out.println("[MSGBUSMGT:] DXCluster Message detected ");
+														 * visible chat members, otherwise the user could try to address an
-
+														 * offline callsign and receive server-side errors.
-				int index = checkListForChatMemberIndexByCallSign(this.client.getLst_chatMemberList(),
+														 *
-						stateChangeMember);
+														 * Therefore UM3 updates existing active members only. Unknown UM3 calls
-
+														 * are intentionally ignored; if the station joins later, UA0/UA5/UA2
-				//-1 could be the case if mycall is processed
+														 * will deliver the complete current user information again.
-				if (index != -1) {
+														 */
-					this.client.getLst_chatMemberList().get(index).setName(stateChangeMember.getName());
+														if (!client.getChatPreferences().getStn_loginCallSign().equalsIgnoreCase(stateChangeMember.getCallSign())) {
-					this.client.getLst_chatMemberList().get(index).setQra(stateChangeMember.getQra());
+															boolean updatedActiveMember = this.client.updateActiveChatMemberInfoIfPresent(stateChangeMember);
-					this.client.getLst_chatMemberList().get(index).setState(stateChangeMember.getState());
+															if (updatedActiveMember) {
+																this.client.getDbHandler().storeChatMember(stateChangeMember); // TODO: not clean, it should be an update
+															} else {
+																System.out.println("[MSGBUSMGT, Info:] UM3 ignored for inactive user: "
+																		+ stateChangeMember.getCallSign() + " / " + stateChangeMember.getChatCategory());
+															}
+														}
 													}
 
 												} else
@@ -1297,6 +1301,8 @@ public class MessageBusManagementThread extends Thread {
 
 														chategoryForMessageAndMessageSender = newMessageArrived.getChatCategory();
 														newMessageArrived.setMessageGeneratedTime(splittedMessageLine[2]);
+														newMessageArrived.setMessageSenderName(splittedMessageLine[4]);
+														newMessageArrived.setMessageText(splittedMessageLine[6]);
 
 														if (splittedMessageLine[3].equals("SERVER")) {
 															ChatMember dummy = new ChatMember();
@@ -1309,76 +1315,16 @@ public class MessageBusManagementThread extends Thread {
 
 														} else {
 
-					ChatMember sender = new ChatMember();
+															newMessageArrived.setSender(resolveInboundSender(
-					sender.setCallSign(splittedMessageLine[3]);
+																	splittedMessageLine[3],
-					sender.setChatCategory(chategoryForMessageAndMessageSender);
+																	chategoryForMessageAndMessageSender,
-
+																	newMessageArrived));
-					int index = checkListForChatMemberIndexByCallSign(this.client.getLst_chatMemberList(), sender);
-
-					if (index != -1) {
-						//user not found in the chatmember list
-						try {
-//							newMessageArrived.setSender(this.client.getLst_chatMemberList().get(index)); // set sender to member of
-//							this.client.getLst_chatMemberList().get(index).setActivityTimeLastInEpoch(new Utils4KST().time_generateCurrentEpochTime());
-
-							ChatMember senderObj = this.client.getLst_chatMemberList().get(index);
-							newMessageArrived.setSender(senderObj);
-							senderObj.setActivityTimeLastInEpoch(new Utils4KST().time_generateCurrentEpochTime());
-
-							// Remember last inbound category per callsignRaw (required for correct send-routing later)
-							this.client.rememberLastInboundCategory(senderObj.getCallSignRaw(), senderObj.getChatCategory());
-
-							// Metrics for scoring: momentum, response-time, no-reply, positive signals
-							this.client.getStationMetricsService().onInboundMessage(
-									senderObj.getCallSignRaw(),
-									System.currentTimeMillis(),
-									newMessageArrived.getMessageText(),
-									this.client.getChatPreferences(),
-									this.client.getChatPreferences().getStn_loginCallSign()
-							);
-
-							// Activity/category changes influence priority => request recompute
-							this.client.getScoreService().requestRecompute("rx-chat-message");
-
-						} catch (Exception exc) {
-							ChatMember aSenderDummy = new ChatMember();
-							aSenderDummy.setCallSign(splittedMessageLine[3] + "[n/a]");
-							aSenderDummy.setAirPlaneReflectInfo(new AirPlaneReflectionInfo());
-							newMessageArrived.setSender(aSenderDummy);
-							System.out.println("MsgBusmgtT: Catched Error! " + exc.getMessage() + " // " + splittedMessageLine[3] + " is not in the list! Faking sender!");
-							exc.printStackTrace();
-						}
-						// b4 init list
-					} else {
-						//user not found in chatmember list, mark it, sender can not be set
-						if (!sender.getCallSign().equals(this.client.getChatPreferences().getStn_loginCallSign().toUpperCase())) {
-							sender.setCallSign("[n/a]" + sender.getCallSign());
-							// if someone sent a message without being in the userlist (cause
-							// on4kst missed implementing....), callsign will be marked
-						} else {
-							//that means, message was by own station, broadcasted to all other
-							ChatMember dummy = new ChatMember();
-							dummy.setCallSign("ALL");
-							newMessageArrived.setReceiver(dummy);
-
-							AirPlaneReflectionInfo preventNullpointerExc = new AirPlaneReflectionInfo();
-							preventNullpointerExc.setAirPlanesReachableCntr(0);
-							sender.setAirPlaneReflectInfo(preventNullpointerExc);
-							newMessageArrived.setSender(sender); //my own call is the sender
-						}
 														}
 
-//					newMessageArrived.setSender(this.client.getChatMemberTable().get(splittedMessageLine[3]));
-				}
-
-				newMessageArrived.setMessageSenderName(splittedMessageLine[4]);
-				newMessageArrived.setMessageText(splittedMessageLine[6]);
 
 														if (splittedMessageLine[7].equals("0")) {
-					// message is not directed to anyone, move it to the cq messages!
+															// message is not directed to anyone, move it to the cq messages.
-					ChatMember dummy = new ChatMember();
+															newMessageArrived.setReceiver(createAllReceiver());
-					dummy.setCallSign("ALL");
-					newMessageArrived.setReceiver(dummy);
 
 //					this.client.getLst_globalChatMessageList().add(0, newMessageArrived); // sdtout to all message-List
 															this.client.publishChatMessage(newMessageArrived); // sdtout to all message-List (new from v1.7)
@@ -1386,35 +1332,9 @@ public class MessageBusManagementThread extends Thread {
 														} else {
 															//message is directed to another chatmember, process as such!
 
-					ChatMember receiver = new ChatMember();
+															newMessageArrived.setReceiver(resolveInboundReceiver(
-
+																	splittedMessageLine[7],
-					receiver.setChatCategory(chategoryForMessageAndMessageSender); //got out of message itself
+																	chategoryForMessageAndMessageSender));
-
-					receiver.setCallSign(splittedMessageLine[7]);
-
-					int index = checkListForChatMemberIndexByCallSign(this.client.getLst_chatMemberList(), receiver);
-
-					if (index != -1) {
-						newMessageArrived.setReceiver(this.client.getLst_chatMemberList().get(index));// -1: Member left Chat
-						// before...
-					} else { //found in active member list
-
-						if (receiver.getCallSign().equals(client.getChatPreferences().getStn_loginCallSign())) {
-							/**
-							 * If mycallsign sent a message to the server, server will publish that message and
-							 * send it to all chatmember including me.
-							 * As mycall is not in the userlist,  the message would not been displayed if I handle
-							 * it in the next case (marking left user, just for information). But I want an echo.
-							 */
-
-							receiver.setCallSign(client.getChatPreferences().getStn_loginCallSign());
-							newMessageArrived.setReceiver(receiver);
-						} else {
-							//this are user which left chat but had been adressed by this message
-							receiver.setCallSign(receiver.getCallSign() + "(left)");
-							newMessageArrived.setReceiver(receiver);
-						}
-					}
 
 //					System.out.println("message directed to: " + newMessageArrived.getReceiver().getCallSign() + ". EQ?: " + this.client.getownChatMemberObject().getCallSign() + " sent by: " + newMessageArrived.getSender().getCallSign().toUpperCase() + " -> EQ?: "+ this.client.getChatPreferences().getLoginCallSign().toUpperCase());
 
@@ -1447,7 +1367,16 @@ public class MessageBusManagementThread extends Thread {
 
 																} else {
 																	//message sent to other user
-							if (DirectionUtils.isInAngleAndRange(client.getChatPreferences().getStn_loginLocatorMainCat(),
+																	// message sent from one other station to another other station
+																	boolean senderHasLocator = newMessageArrived.getSender().getQra() != null
+																			&& !newMessageArrived.getSender().getQra().isBlank();
+
+																	boolean receiverHasLocator = newMessageArrived.getReceiver().getQra() != null
+																			&& !newMessageArrived.getReceiver().getQra().isBlank();
+
+																	if (senderHasLocator && receiverHasLocator) {
+																		if (DirectionUtils.isInAngleAndRange(
+																				client.getChatPreferences().getStn_loginLocatorMainCat(),
 																				newMessageArrived.getSender().getQra(),
 																				newMessageArrived.getReceiver().getQra(),
 																				client.getChatPreferences().getStn_maxQRBDefault(),
@@ -1456,17 +1385,24 @@ public class MessageBusManagementThread extends Thread {
 																			newMessageArrived.getSender().setInAngleAndRange(true);
 
 																		} else {
-
+																			newMessageArrived.getSender().setInAngleAndRange(false);
+																		}
+																	} else {
+																		/*
+																		 * Historic fallback senders/receivers may not have locators.
+																		 * The message is still valid and should be displayed, but angle/range
+																		 * analysis cannot be calculated without both locators.
+																		 */
 																		newMessageArrived.getSender().setInAngleAndRange(false);
 																	}
 
-//							this.client.getLst_globalChatMessageList().add(0, newMessageArrived);
+																	this.client.publishChatMessage(newMessageArrived);
-							this.client.publishChatMessage(newMessageArrived); // sdtout to all message-List (new from v1.7)
 //						System.out.println("MSGBS bgfx: tx call = " + newMessageArrived.getSender().getCallSign() + " / rx call = " + newMessageArrived.getReceiver().getCallSign());
 																}
 															} catch (NullPointerException referenceDeletedByUserLeftChatDuringMessageprocessing) {
-						System.out.println("MSGBS bgfx, <<<catched error>>>: referenced user left the chat during messageprocessing or message got before user entered chat message: " + referenceDeletedByUserLeftChatDuringMessageprocessing.getStackTrace());
+																System.out.println("MSGBS bgfx, <<<catched error>>>: referenced user left the chat during messageprocessing or message got before user entered chat message: "
-//						referenceDeletedByUserLeftChatDuringMessageprocessing.printStackTrace();
+																		+ referenceDeletedByUserLeftChatDuringMessageprocessing.getMessage());
+																referenceDeletedByUserLeftChatDuringMessageprocessing.printStackTrace();
 															}
 
 															// sdtout to me message-List
@@ -1479,7 +1415,8 @@ public class MessageBusManagementThread extends Thread {
 																	+ " " + newMessageArrived.getSender().getCallSign() + ", " + newMessageArrived.getMessageSenderName() + " -> "
 																	+ newMessageArrived.getReceiver().getCallSign() + ": " + newMessageArrived.getMessageText());
 														} catch (Exception exceptionOccured) {
-					System.out.println("[MSGMgtBus: ERROR CHATCHED ON MAYBE NULL ISSUE]: " + exceptionOccured.getMessage() + "\n" + exceptionOccured.getStackTrace());
+															System.out.println("[MSGMgtBus: ERROR CHATCHED ON MAYBE NULL ISSUE]: " + exceptionOccured.getMessage());
+															exceptionOccured.printStackTrace();
 														}
 
 														// --- Band/QRG recognition (fills ChatMember.knownActiveBands) ---
@@ -1534,7 +1471,7 @@ public class MessageBusManagementThread extends Thread {
 
 
 																for (int i = 0; i < 10; i++) {
-					client.getLst_globalChatMessageList().add(pwErrorMsg);
+																	client.publishChatMessage(pwErrorMsg);
 //					client.getLst_toMeMessageList().add(pwErrorMsg);
 //					client.getLst_toAllMessageList().add(pwErrorMsg);
 																}
@@ -1546,6 +1483,10 @@ public class MessageBusManagementThread extends Thread {
 //				this.client.disconnect();
 															}
 
+															else if (splittedMessageLine[0].equals("DE")) {
+																// DXCluster delimiter/end marker; intentionally ignored.
+															}
+
 															else {
 
 //				bufwrtrDBGMSGOut.write(new Utils4KST().time_generateCurrentMMDDhhmmTimeString()
@@ -1751,6 +1692,10 @@ public class MessageBusManagementThread extends Thread {
 					} catch (SQLException e) {
 						System.out.println("MsgBusMgt: process23001 went wrong / SQL Error");
 						e.printStackTrace();
+					} catch (RuntimeException e) {
+						System.out.println("MsgBusMgt: process23001 went wrong / Runtime Error while processing: "
+								+ messageTextRaw.getMessageText());
+						e.printStackTrace();
 					}
 				}
 

src/main/java/kst4contest/view/Kst4ContestApplication.java

@@ -5016,7 +5016,7 @@ public class Kst4ContestApplication extends Application implements StatusUpdateL
 		help2.setOnAction(new EventHandler<ActionEvent>() {
 			public void handle(ActionEvent event) {
 
-				getHostServices().showDocument("https://www.paypal.com/paypalme/do5amf");
+				getHostServices().showDocument("https://ko-fi.com/praktimarc");
 
 			}
 		});

src/main/java/kst4contest/view/map/MapHtmlResources.java

@@ -13,8 +13,12 @@ import java.nio.charset.StandardCharsets;
  * - inspectPoint(x,y) returns what is under the cursor
  * - zoomIn()/zoomOut() are callable from Java
  * - grid / beam / connection use non-interactive panes
- * - JavaScript logs are forwarded to Java through javaMapBridge
+ * - JavaScript errors are forwarded to Java through javaMapBridge
  * - setTheme(light|dark) aligns the map with the JavaFX application theme
+ *
+ * Important:
+ * This version intentionally uses integer Leaflet zoom levels again.
+ * Fractional zoom in JavaFX WebView caused unreliable marker positioning.
  */
 public final class MapHtmlResources {
 
@@ -184,6 +188,111 @@ public final class MapHtmlResources {
                             font-weight: 800;
                         }
 
+                        .station-cluster-wrapper {
+                            background: transparent;
+                            border: none;
+                            box-shadow: none;
+                        }
+
+                        .station-cluster-root {
+                            position: relative;
+                            width: 1px;
+                            height: 1px;
+                            pointer-events: auto;
+                            cursor: pointer;
+                            user-select: none;
+                        }
+
+                        /*
+                         * Cluster design aligned with normal KST4Contest station markers:
+                         * - dark center like station-dot
+                         * - blue border for normal clustered stations
+                         * - yellow border when the cluster contains worked stations
+                         * - orange hover border similar to selected station state
+                         */
+                        .station-cluster-bubble {
+                            position: absolute;
+                            left: -16px;
+                            top: -16px;
+                            min-width: 32px;
+                            height: 32px;
+                            padding: 0 7px;
+                            border-radius: 18px;
+                            background: #1d1d1d;
+                            color: #f4f7fa;
+                            border: 2px solid #4da6ff;
+                            box-shadow:
+                                0 0 0 1px rgba(0, 0, 0, 0.35),
+                                0 2px 7px rgba(0, 0, 0, 0.42);
+                            box-sizing: border-box;
+                            font-size: 13px;
+                            font-weight: 800;
+                            line-height: 28px;
+                            text-align: center;
+                            white-space: nowrap;
+                        }
+
+                        .station-cluster-bubble.medium {
+                            left: -18px;
+                            top: -18px;
+                            min-width: 36px;
+                            height: 36px;
+                            border-radius: 20px;
+                            font-size: 14px;
+                            line-height: 32px;
+                        }
+
+                        .station-cluster-bubble.large {
+                            left: -21px;
+                            top: -21px;
+                            min-width: 42px;
+                            height: 42px;
+                            border-radius: 23px;
+                            font-size: 15px;
+                            line-height: 38px;
+                        }
+
+                        .station-cluster-bubble.worked {
+                            border-color: #ffd24d;
+                        }
+
+                        .station-cluster-bubble.warning {
+                            border-color: #00ff66;
+                            color: #00ff66;
+                        }
+
+                        .station-cluster-root:hover .station-cluster-bubble {
+                            border-color: #ff9900;
+                            box-shadow:
+                                0 0 0 2px rgba(255, 153, 0, 0.28),
+                                0 2px 9px rgba(0, 0, 0, 0.48);
+                        }
+
+                        body.kst-theme-dark .station-cluster-bubble {
+                            background: #202428;
+                            color: #f1f3f5;
+                            border-color: #4da6ff;
+                            box-shadow:
+                                0 0 0 1px rgba(255, 255, 255, 0.12),
+                                0 2px 8px rgba(0, 0, 0, 0.58);
+                        }
+
+                        body.kst-theme-dark .station-cluster-bubble.worked {
+                            border-color: #ffd24d;
+                        }
+
+                        body.kst-theme-dark .station-cluster-bubble.warning {
+                            border-color: #00ff66;
+                            color: #00ff66;
+                        }
+
+                        body.kst-theme-dark .station-cluster-root:hover .station-cluster-bubble {
+                            border-color: #ff9900;
+                            box-shadow:
+                                0 0 0 2px rgba(255, 153, 0, 0.32),
+                                0 2px 10px rgba(0, 0, 0, 0.65);
+                        }
+
                         .maidenhead-grid-label-wrapper {
                             background: transparent;
                             border: none;
@@ -225,9 +334,6 @@ public final class MapHtmlResources {
                 <script>window._kstTileProxyPort=__TILE_PROXY_PORT__;</script>
 
                 <script>
-                
-                
-                
                     window.kstMapApi = (function () {
                         let map;
                         let stationLayer;
@@ -235,11 +341,77 @@ public final class MapHtmlResources {
                         let beamLayer;
                         let connectionLayer;
                         let profileHoverMarker;
+
+                        /*
+                         * Currently visible individual station markers.
+                         *
+                         * A callsign is present here only when it is rendered individually.
+                         * If the station is inside a cluster, stationsByCallsignRaw is used
+                         * for focus/zoom operations.
+                         */
                         let markersByCallsignRaw = {};
+
+                        /*
+                         * All station data as received from Java.
+                         */
+                        let stationData = [];
+                        let stationsByCallsignRaw = {};
+
+                        let clustersById = {};
+                        let clusterSequence = 0;
+
                         let activeTheme = 'light';
                         let invalidateNotifyTimer = 0;
 
+                        /*
+                         * Integer zoom only.
+                         *
+                         * Fractional zoom is intentionally disabled because JavaFX WebView
+                         * and Leaflet marker positioning were unreliable at intermediate
+                         * zoom levels.
+                         */
+                        const KST_ZOOM_STEP = 1;
+                        const KST_MIN_ZOOM = 3;
+                        const KST_MAX_ZOOM = 18;
+
+                        /*
+                         * Enables verbose JavaScript map logging.
+                         *
+                         * Keep this false for normal operation. jsError() still reports
+                         * real errors.
+                         */
+                        const KST_MAP_DEBUG = false;
+
+                        /*
+                         * Cluster settings.
+                         *
+                         * With integer zoom, clustering is disabled at zoom >= 8.
+                         * At zoom 7 only very close stations are grouped.
+                         */
+                        const KST_CLUSTER_DISABLE_ZOOM = 8;
+
+                        /*
+                         * Do not cluster pairs immediately. Two nearby stations are still
+                         * readable and should remain individually clickable.
+                         */
+                        const KST_CLUSTER_MIN_STATIONS = 3;
+
+                        /*
+                         * Cluster cell sizes in screen pixels.
+                         *
+                         * Smaller cells make clustering less aggressive. Stations must be
+                         * closer together on screen before they are grouped.
+                         */
+                        const KST_CLUSTER_CELL_SIZE_HIGH_ZOOM = 55;
+                        const KST_CLUSTER_CELL_SIZE_MEDIUM_ZOOM = 70;
+                        const KST_CLUSTER_CELL_SIZE_LOW_ZOOM = 95;
+                        const KST_CLUSTER_CELL_SIZE_VERY_LOW_ZOOM = 125;
+
                         function jsLog(message) {
+                            if (!KST_MAP_DEBUG) {
+                                return;
+                            }
+
                             try {
                                 if (window.javaMapBridge) {
                                     window.javaMapBridge.onJsLog(String(message));
@@ -358,6 +530,331 @@ public final class MapHtmlResources {
                                 + '</div>';
                         }
 
+                        function getStationCallsignKey(station) {
+                            if (!station || station.callSignRaw === null || station.callSignRaw === undefined) {
+                                return '';
+                            }
+
+                            return String(station.callSignRaw);
+                        }
+
+                        function isStationPositionValid(station) {
+                            if (!station) {
+                                return false;
+                            }
+
+                            return isFinite(station.latitudeDeg) && isFinite(station.longitudeDeg);
+                        }
+
+                        /**
+                         * Returns true for stations that must not be hidden inside a cluster.
+                         *
+                         * These stations remain individually visible even at low zoom levels
+                         * because they are operationally important during contest operation.
+                         */
+                        function shouldRenderStationIndividually(station) {
+                            if (!station) {
+                                return false;
+                            }
+
+                            if (station.selected) {
+                                return true;
+                            }
+
+                            if (station.warningToMyDirection) {
+                                return true;
+                            }
+
+                            return false;
+                        }
+
+                        /**
+                         * Returns the cluster grid size in screen pixels for the current zoom level.
+                         *
+                         * The cluster calculation is screen-based, not locator-based. This makes
+                         * the decision match the real visual problem: too many labels in the same
+                         * screen area.
+                         */
+                        function getClusterCellSizePx() {
+                            if (!map) {
+                                return KST_CLUSTER_CELL_SIZE_MEDIUM_ZOOM;
+                            }
+
+                            const zoom = Number(map.getZoom());
+
+                            if (zoom >= 7) {
+                                return KST_CLUSTER_CELL_SIZE_HIGH_ZOOM;
+                            }
+
+                            if (zoom >= 6) {
+                                return KST_CLUSTER_CELL_SIZE_MEDIUM_ZOOM;
+                            }
+
+                            if (zoom >= 5) {
+                                return KST_CLUSTER_CELL_SIZE_LOW_ZOOM;
+                            }
+
+                            return KST_CLUSTER_CELL_SIZE_VERY_LOW_ZOOM;
+                        }
+
+                        function buildClusterMarkerHtml(clusterId, clusterStations) {
+                            const count = clusterStations ? clusterStations.length : 0;
+
+                            let bubbleClasses = 'station-cluster-bubble';
+
+                            if (count >= 20) {
+                                bubbleClasses += ' large';
+                            } else if (count >= 8) {
+                                bubbleClasses += ' medium';
+                            }
+
+                            const containsWorkedStation = clusterStations
+                                && clusterStations.some(station => station && station.worked);
+
+                            const containsWarningStation = clusterStations
+                                && clusterStations.some(station => station && station.warningToMyDirection);
+
+                            if (containsWarningStation) {
+                                bubbleClasses += ' warning';
+                            } else if (containsWorkedStation) {
+                                bubbleClasses += ' worked';
+                            }
+
+                            return '<div class="station-cluster-root" data-cluster-id="' + escapeHtml(clusterId) + '">'
+                                + '<div class="' + bubbleClasses + '">' + count + '</div>'
+                                + '</div>';
+                        }
+
+                        function buildClusterTooltipHtml(clusterStations) {
+                            if (!clusterStations || clusterStations.length === 0) {
+                                return '';
+                            }
+
+                            const callsigns = clusterStations
+                                .map(station => station.markerLabel || station.callSignRaw || station.callSign || '')
+                                .filter(value => value !== null && value !== undefined && String(value).trim() !== '')
+                                .map(value => String(value).trim())
+                                .sort();
+
+                            const maxPreviewCount = 20;
+                            const preview = callsigns
+                                .slice(0, maxPreviewCount)
+                                .map(value => escapeHtml(value))
+                                .join('<br>');
+
+                            const remainingCount = Math.max(0, callsigns.length - maxPreviewCount);
+
+                            let html = '<b>' + clusterStations.length + ' stations</b>';
+
+                            if (preview) {
+                                html += '<br>' + preview;
+                            }
+
+                            if (remainingCount > 0) {
+                                html += '<br>+' + remainingCount + ' more';
+                            }
+
+                            html += '<br><i>Click to zoom in</i>';
+
+                            return html;
+                        }
+
+                        function addStationMarker(station) {
+                            if (!stationLayer || !isStationPositionValid(station)) {
+                                return;
+                            }
+
+                            const marker = L.marker(
+                                [station.latitudeDeg, station.longitudeDeg],
+                                {
+                                    interactive: true,
+                                    keyboard: false,
+                                    icon: L.divIcon({
+                                        className: 'station-marker-wrapper',
+                                        html: buildStationMarkerHtml(station),
+                                        iconSize: [1, 1],
+                                        iconAnchor: [0, 0]
+                                    })
+                                }
+                            );
+
+                            marker.addTo(stationLayer);
+
+                            const callSignKey = getStationCallsignKey(station);
+                            if (callSignKey) {
+                                markersByCallsignRaw[callSignKey] = marker;
+                            }
+                        }
+
+                        function addClusterMarker(clusterStations) {
+                            if (!stationLayer || !clusterStations || clusterStations.length === 0) {
+                                return;
+                            }
+
+                            let latSum = 0.0;
+                            let lonSum = 0.0;
+                            let validCount = 0;
+
+                            clusterStations.forEach(station => {
+                                if (isStationPositionValid(station)) {
+                                    latSum += Number(station.latitudeDeg);
+                                    lonSum += Number(station.longitudeDeg);
+                                    validCount++;
+                                }
+                            });
+
+                            if (validCount === 0) {
+                                return;
+                            }
+
+                            const centerLat = latSum / validCount;
+                            const centerLon = lonSum / validCount;
+
+                            const clusterId = 'cluster-' + (++clusterSequence);
+                            clustersById[clusterId] = clusterStations;
+
+                            const clusterMarker = L.marker(
+                                [centerLat, centerLon],
+                                {
+                                    interactive: true,
+                                    keyboard: false,
+                                    icon: L.divIcon({
+                                        className: 'station-cluster-wrapper',
+                                        html: buildClusterMarkerHtml(clusterId, clusterStations),
+                                        iconSize: [1, 1],
+                                        iconAnchor: [0, 0]
+                                    })
+                                }
+                            );
+
+                            clusterMarker.on('click', function () {
+                                zoomToCluster(clusterStations);
+                            });
+
+                            clusterMarker.bindTooltip(buildClusterTooltipHtml(clusterStations), {
+                                direction: 'top',
+                                sticky: true,
+                                opacity: 0.95
+                            });
+
+                            clusterMarker.addTo(stationLayer);
+                        }
+
+                        function renderAllStationsIndividually() {
+                            stationData.forEach(station => {
+                                addStationMarker(station);
+                            });
+                        }
+
+                        /**
+                         * Renders stations with simple screen-grid clustering.
+                         *
+                         * Important stations such as the currently selected station and warning
+                         * stations are rendered individually before clustering. They remain
+                         * visible even at low zoom levels.
+                         */
+                        function renderClusteredStations() {
+                            const clusterCellSizePx = getClusterCellSizePx();
+                            const buckets = {};
+
+                            stationData.forEach(station => {
+                                if (!isStationPositionValid(station)) {
+                                    return;
+                                }
+
+                                if (shouldRenderStationIndividually(station)) {
+                                    addStationMarker(station);
+                                    return;
+                                }
+
+                                const point = map.latLngToContainerPoint([station.latitudeDeg, station.longitudeDeg]);
+                                const cellX = Math.floor(point.x / clusterCellSizePx);
+                                const cellY = Math.floor(point.y / clusterCellSizePx);
+                                const key = cellX + ':' + cellY;
+
+                                if (!buckets[key]) {
+                                    buckets[key] = [];
+                                }
+
+                                buckets[key].push(station);
+                            });
+
+                            Object.keys(buckets).forEach(key => {
+                                const bucketStations = buckets[key];
+
+                                if (bucketStations.length >= KST_CLUSTER_MIN_STATIONS) {
+                                    addClusterMarker(bucketStations);
+                                } else {
+                                    bucketStations.forEach(station => addStationMarker(station));
+                                }
+                            });
+                        }
+
+                        /**
+                         * Re-renders station markers for the current zoom and viewport.
+                         *
+                         * This is called when stations arrive from Java and after zoom/move
+                         * events, because screen-grid clusters depend on the current viewport.
+                         */
+                        function renderStationMarkers() {
+                            if (!map || !stationLayer) {
+                                return;
+                            }
+
+                            stationLayer.clearLayers();
+                            markersByCallsignRaw = {};
+                            clustersById = {};
+                            clusterSequence = 0;
+
+                            if (!stationData || stationData.length === 0) {
+                                return;
+                            }
+
+                            if (Number(map.getZoom()) >= KST_CLUSTER_DISABLE_ZOOM) {
+                                renderAllStationsIndividually();
+                            } else {
+                                renderClusteredStations();
+                            }
+                        }
+
+                        /**
+                         * Zooms into a cluster.
+                         *
+                         * A cluster click does not select one station. It moves the map towards
+                         * the cluster center and increases zoom until individual stations become
+                         * visible.
+                         */
+                        function zoomToCluster(clusterStations) {
+                            if (!map || !clusterStations || clusterStations.length === 0) {
+                                return;
+                            }
+
+                            const latLngs = [];
+
+                            clusterStations.forEach(station => {
+                                if (isStationPositionValid(station)) {
+                                    latLngs.push(L.latLng(station.latitudeDeg, station.longitudeDeg));
+                                }
+                            });
+
+                            if (latLngs.length === 0) {
+                                return;
+                            }
+
+                            const bounds = L.latLngBounds(latLngs);
+                            const currentZoom = Number(map.getZoom());
+
+                            const targetZoom = clampZoomToLeafletLimits(
+                                Math.min(KST_CLUSTER_DISABLE_ZOOM, currentZoom + 1)
+                            );
+
+                            map.setView(bounds.getCenter(), targetZoom, {
+                                animate: false
+                            });
+
+                            notifyViewport();
+                        }
+
                         function init() {
                             if (map) {
                                 return true;
@@ -372,6 +869,17 @@ public final class MapHtmlResources {
 
                             map = L.map('map', {
                                 zoomControl: true,
+                                minZoom: KST_MIN_ZOOM,
+                                maxZoom: KST_MAX_ZOOM,
+
+                                /*
+                                 * Integer zoom only.
+                                 * This keeps station positions stable in JavaFX WebView.
+                                 */
+                                zoomSnap: 1,
+                                zoomDelta: 1,
+                                wheelPxPerZoomLevel: 120,
+
                                 zoomAnimation: false,
                                 fadeAnimation: false,
                                 markerZoomAnimation: false,
@@ -383,7 +891,8 @@ public final class MapHtmlResources {
                             const tileLayer = L.tileLayer(
                                 'http://127.0.0.1:' + window._kstTileProxyPort + '/tiles/{s}/{z}/{x}/{y}.png',
                                 {
-                                    maxZoom: 18,
+                                    minZoom: KST_MIN_ZOOM,
+                                    maxZoom: KST_MAX_ZOOM,
                                     updateWhenZooming: false,
                                     keepBuffer: 4,
                                     attribution: '&copy; <a href="https://www.openstreetmap.org/copyright">OpenStreetMap</a>'
@@ -419,12 +928,12 @@ public final class MapHtmlResources {
                             connectionLayer = L.layerGroup().addTo(map);
 
                             map.on('zoomend', function () {
-                                jsLog('zoomend -> ' + map.getZoom());
+                                renderStationMarkers();
                                 notifyViewport();
                             });
 
                             map.on('moveend', function () {
-                                jsLog('moveend');
+                                renderStationMarkers();
                                 notifyViewport();
                             });
 
@@ -476,20 +985,39 @@ public final class MapHtmlResources {
                             invalidateSize();
                         }
 
-                        function zoomIn() {
+                        /**
+                         * Keeps the zoom value inside the explicit KST zoom limits.
+                         */
+                        function clampZoomToLeafletLimits(zoom) {
+                            return Math.max(KST_MIN_ZOOM, Math.min(KST_MAX_ZOOM, zoom));
+                        }
+
+                        /**
+                         * Changes the zoom in stable integer steps.
+                         */
+                        function changeZoomByKstStep(delta) {
                             if (!map) {
                                 return;
                             }
 
-                            map.setZoom(map.getZoom() + 1, { animate: false });
+                            const currentZoom = Number(map.getZoom());
+                            const nextZoom = clampZoomToLeafletLimits(currentZoom + delta);
+
+                            if (nextZoom === currentZoom) {
+                                return;
+                            }
+
+                            map.setZoom(nextZoom, {
+                                animate: false
+                            });
+                        }
+
+                        function zoomIn() {
+                            changeZoomByKstStep(KST_ZOOM_STEP);
                         }
 
                         function zoomOut() {
-                            if (!map) {
+                            changeZoomByKstStep(-KST_ZOOM_STEP);
-                                return;
-                            }
-
-                            map.setZoom(map.getZoom() - 1, { animate: false });
                         }
 
                         function getViewportState() {
@@ -522,6 +1050,12 @@ public final class MapHtmlResources {
                                     return 'station|' + callSignRaw + '|' + el.tagName + '|' + (el.className || '') + '|' + (el.textContent || '').trim();
                                 }
 
+                                const clusterRoot = el.closest('.station-cluster-root');
+                                if (clusterRoot) {
+                                    const clusterId = clusterRoot.getAttribute('data-cluster-id') || '';
+                                    return 'cluster|' + clusterId + '|' + el.tagName + '|' + (el.className || '') + '|' + (el.textContent || '').trim();
+                                }
+
                                 const zoomInButton = el.closest('.leaflet-control-zoom-in');
                                 if (zoomInButton) {
                                     return 'zoomIn||' + el.tagName + '|' + (el.className || '') + '|' + (el.textContent || '').trim();
@@ -542,8 +1076,8 @@ public final class MapHtmlResources {
                             if (!init()) {
                                 return;
                             }
-                            jsLog('setHome lat=' + lat + ' lon=' + lon + ' zoom=' + zoom);
+
-                            map.setView([lat, lon], zoom);
+                            map.setView([lat, lon], clampZoomToLeafletLimits(Math.round(Number(zoom))));
                         }
 
                         function setStations(stationsJson) {
@@ -551,30 +1085,17 @@ public final class MapHtmlResources {
                                 return;
                             }
 
-                            stationLayer.clearLayers();
+                            stationData = JSON.parse(stationsJson);
-                            markersByCallsignRaw = {};
+                            stationsByCallsignRaw = {};
 
-                            const stations = JSON.parse(stationsJson);
+                            stationData.forEach(station => {
-                            jsLog('setStations count=' + stations.length);
+                                const callSignKey = getStationCallsignKey(station);
-
+                                if (callSignKey) {
-                            stations.forEach(station => {
+                                    stationsByCallsignRaw[callSignKey] = station;
-                                const marker = L.marker(
-                                    [station.latitudeDeg, station.longitudeDeg],
-                                    {
-                                        interactive: true,
-                                        keyboard: false,
-                                        icon: L.divIcon({
-                                            className: 'station-marker-wrapper',
-                                            html: buildStationMarkerHtml(station),
-                                            iconSize: [1, 1],
-                                            iconAnchor: [0, 0]
-                                        })
                                 }
-                                );
-
-                                marker.addTo(stationLayer);
-                                markersByCallsignRaw[station.callSignRaw] = marker;
                             });
+
+                            renderStationMarkers();
                         }
 
                         function setBeam(beamJson) {
@@ -592,8 +1113,6 @@ public final class MapHtmlResources {
                                 return;
                             }
 
-                            jsLog('setBeam points=' + points.length);
-
                             const latLngs = points.map(point => [point.lat, point.lon]);
 
                             L.polygon(latLngs, {
@@ -621,8 +1140,6 @@ public final class MapHtmlResources {
                                 return;
                             }
 
-                            jsLog('setConnection');
-
                             L.polyline(points.map(point => [point.lat, point.lon]), {
                                 pane: 'connectionPane',
                                 color: connectionColor(),
@@ -671,7 +1188,6 @@ public final class MapHtmlResources {
                             gridLayer.clearLayers();
 
                             const cells = JSON.parse(gridJson);
-                            jsLog('setGrid cells=' + cells.length);
 
                             cells.forEach(cell => {
                                 const rectangle = L.rectangle(
@@ -717,21 +1233,33 @@ public final class MapHtmlResources {
                             }
 
                             const marker = markersByCallsignRaw[callSignRaw];
-                             if (!marker) {
+                            if (marker) {
-                                 jsLog('focusCallsignRaw skipped for ' + callSignRaw);
-                                 return;
-                             }
-                
-                             jsLog('focusCallsignRaw ' + callSignRaw);
-                
                                 map.panTo(marker.getLatLng(), {
                                     animate: false
                                 });
 
                                 notifyViewport();
+                                return;
                             }
 
+                            /*
+                             * If the station is currently hidden inside a cluster, there is no
+                             * individual marker. Use the raw station data and zoom in far enough
+                             * so clustering is disabled and the station becomes visible.
+                             */
+                            const station = stationsByCallsignRaw[callSignRaw];
+                            if (station && isStationPositionValid(station)) {
+                                const focusZoom = clampZoomToLeafletLimits(
+                                    Math.max(Number(map.getZoom()), KST_CLUSTER_DISABLE_ZOOM)
+                                );
 
+                                map.setView([station.latitudeDeg, station.longitudeDeg], focusZoom, {
+                                    animate: false
+                                });
+
+                                notifyViewport();
+                            }
+                        }
                          
                         return {
                             init: init,

src/main/java/kst4contest/view/map/StationMapView.java

@@ -41,6 +41,14 @@ import javafx.scene.layout.ColumnConstraints;
  */
 public final class StationMapView {
 
+    /**
+     * Enables verbose map debug output.
+     *
+     * Keep this false for normal operation because scroll and viewport logs are very
+     * noisy during map interaction.
+     */
+    private static final boolean MAP_DEBUG_LOGGING = false;
+
     private final PathProfileChart detailPathProfileChart = new PathProfileChart();
     private final Label detailPathModeValue = new Label("-");
 
@@ -287,12 +295,17 @@ public final class StationMapView {
         webView.addEventHandler(MouseEvent.MOUSE_CLICKED, event -> handleWebViewClick(event));
 
         webView.addEventHandler(ScrollEvent.SCROLL, event -> {
+
+            if (MAP_DEBUG_LOGGING) {
                 System.out.println("[StationMap FX] SCROLL x=" + (int) event.getX()
                         + " y=" + (int) event.getY()
                         + " deltaY=" + event.getDeltaY());
+            }
 
             InteractiveTarget target = inspectInteractiveTarget(event.getX(), event.getY());
+            if (MAP_DEBUG_LOGGING) {
                 System.out.println("[StationMap FX] inspect scroll -> " + target);
+            }
 
             if (event.getDeltaY() > 0) {
                 executeMapScriptSafely("window.kstMapApi.zoomIn();");

src/main/resources/web/leaflet/leaflet.css

@@ -650,6 +650,8 @@ svg.leaflet-image-layer.leaflet-interactive path {
     border-right-color: #fff;
 }
 
+
+
 /* Printing */
 
 @media print {

website/_site/about/index.html

@@ -17,7 +17,7 @@
   <meta name="twitter:title" content="About KST4Contest">
   <meta name="twitter:description" content="About KST4Contest and its contest-oriented ON4KST workflow.">
 
-  <link rel="stylesheet" href="/assets/css/main.css?v=1783615687631">
+  <link rel="stylesheet" href="/assets/css/main.css?v=1783632276803">
   <link rel="alternate" type="application/rss+xml" title="KST4Contest News" href="/feed.xml">
 
 <meta property="og:image" content="https://kst4contest.hamradioonline.de/assets/social/kst4contest-og.png">

website/_site/contact/index.html

@@ -17,7 +17,7 @@
   <meta name="twitter:title" content="Contact | KST4Contest">
   <meta name="twitter:description" content="Contact options for KST4Contest.">
 
-  <link rel="stylesheet" href="/assets/css/main.css?v=1783615687631">
+  <link rel="stylesheet" href="/assets/css/main.css?v=1783632276803">
   <link rel="alternate" type="application/rss+xml" title="KST4Contest News" href="/feed.xml">
 
 <meta property="og:image" content="https://kst4contest.hamradioonline.de/assets/social/kst4contest-og.png">

website/_site/download/index.html

@@ -17,7 +17,7 @@
   <meta name="twitter:title" content="Download KST4Contest">
   <meta name="twitter:description" content="Download KST4Contest releases for Windows, Linux and macOS.">
 
-  <link rel="stylesheet" href="/assets/css/main.css?v=1783615687631">
+  <link rel="stylesheet" href="/assets/css/main.css?v=1783632276803">
   <link rel="alternate" type="application/rss+xml" title="KST4Contest News" href="/feed.xml">
 
 <meta property="og:image" content="https://kst4contest.hamradioonline.de/assets/social/kst4contest-og.png">

website/_site/faq/index.html

@@ -17,7 +17,7 @@
   <meta name="twitter:title" content="KST4Contest FAQ">
   <meta name="twitter:description" content="Frequently asked questions about KST4Contest, ON4KST contest operation, AirScout integration and VHF/UHF/SHF contest workflow.">
 
-  <link rel="stylesheet" href="/assets/css/main.css?v=1783615687631">
+  <link rel="stylesheet" href="/assets/css/main.css?v=1783632276803">
   <link rel="alternate" type="application/rss+xml" title="KST4Contest News" href="/feed.xml">
 
 <meta property="og:image" content="https://kst4contest.hamradioonline.de/assets/social/kst4contest-og.png">

website/_site/features/airscout/index.html

@@ -17,7 +17,7 @@
   <meta name="twitter:title" content="AirScout Integration">
   <meta name="twitter:description" content="AirScout information helps operators evaluate AP windows, aircraft scatter timing and candidate stations during VHF/UHF/SHF contests.">
 
-  <link rel="stylesheet" href="/assets/css/main.css?v=1783615687631">
+  <link rel="stylesheet" href="/assets/css/main.css?v=1783632276803">
   <link rel="alternate" type="application/rss+xml" title="KST4Contest News" href="/feed.xml">
 
 <meta property="og:image" content="https://kst4contest.hamradioonline.de/assets/social/kst4contest-og.png">

website/_site/features/dual-chat/index.html

@@ -17,7 +17,7 @@
   <meta name="twitter:title" content="Dual Chat Categories">
   <meta name="twitter:description" content="Dual category support gives contest operators better overview when working across multiple ON4KST chat rooms.">
 
-  <link rel="stylesheet" href="/assets/css/main.css?v=1783615687631">
+  <link rel="stylesheet" href="/assets/css/main.css?v=1783632276803">
   <link rel="alternate" type="application/rss+xml" title="KST4Contest News" href="/feed.xml">
 
 <meta property="og:image" content="https://kst4contest.hamradioonline.de/assets/social/kst4contest-og.png">

website/_site/features/dx-cluster/index.html

@@ -17,7 +17,7 @@
   <meta name="twitter:title" content="DXCluster Server">
   <meta name="twitter:description" content="KST4Contest includes DXCluster functionality to support situational awareness during contest operation.">
 
-  <link rel="stylesheet" href="/assets/css/main.css?v=1783615687631">
+  <link rel="stylesheet" href="/assets/css/main.css?v=1783632276803">
   <link rel="alternate" type="application/rss+xml" title="KST4Contest News" href="/feed.xml">
 
 <meta property="og:image" content="https://kst4contest.hamradioonline.de/assets/social/kst4contest-og.png">

website/_site/features/index.html

@@ -17,7 +17,7 @@
   <meta name="twitter:title" content="KST4Contest Features">
   <meta name="twitter:description" content="Contest-optimized ON4KST features for VHF, UHF and SHF operation.">
 
-  <link rel="stylesheet" href="/assets/css/main.css?v=1783615687631">
+  <link rel="stylesheet" href="/assets/css/main.css?v=1783632276803">
   <link rel="alternate" type="application/rss+xml" title="KST4Contest News" href="/feed.xml">
 
 <meta property="og:image" content="https://kst4contest.hamradioonline.de/assets/social/kst4contest-og.png">

website/_site/features/log-sync/index.html

@@ -17,7 +17,7 @@
   <meta name="twitter:title" content="Log Synchronization">
   <meta name="twitter:description" content="Log synchronization helps KST4Contest understand worked stations, active bands and contest context.">
 
-  <link rel="stylesheet" href="/assets/css/main.css?v=1783615687631">
+  <link rel="stylesheet" href="/assets/css/main.css?v=1783632276803">
   <link rel="alternate" type="application/rss+xml" title="KST4Contest News" href="/feed.xml">
 
 <meta property="og:image" content="https://kst4contest.hamradioonline.de/assets/social/kst4contest-og.png">

website/_site/features/macros/index.html

@@ -17,7 +17,7 @@
   <meta name="twitter:title" content="Macros and Variables">
   <meta name="twitter:description" content="Macros reduce repetitive typing and help operators respond quickly during active ON4KST contest sessions.">
 
-  <link rel="stylesheet" href="/assets/css/main.css?v=1783615687631">
+  <link rel="stylesheet" href="/assets/css/main.css?v=1783632276803">
   <link rel="alternate" type="application/rss+xml" title="KST4Contest News" href="/feed.xml">
 
 <meta property="og:image" content="https://kst4contest.hamradioonline.de/assets/social/kst4contest-og.png">

website/_site/features/priority-score/index.html

@@ -17,7 +17,7 @@
   <meta name="twitter:title" content="Priority Score System">
   <meta name="twitter:description" content="KST4Contest ranks stations by activity, direction, sked context, band information, QRG hints and operator workflow signals.">
 
-  <link rel="stylesheet" href="/assets/css/main.css?v=1783615687631">
+  <link rel="stylesheet" href="/assets/css/main.css?v=1783632276803">
   <link rel="alternate" type="application/rss+xml" title="KST4Contest News" href="/feed.xml">
 
 <meta property="og:image" content="https://kst4contest.hamradioonline.de/assets/social/kst4contest-og.png">

website/_site/features/sked-reminder/index.html

@@ -17,7 +17,7 @@
   <meta name="twitter:title" content="Sked Reminder">
   <meta name="twitter:description" content="KST4Contest keeps skeds in focus while the operator handles chat traffic, logging, bands and aircraft scatter timing.">
 
-  <link rel="stylesheet" href="/assets/css/main.css?v=1783615687631">
+  <link rel="stylesheet" href="/assets/css/main.css?v=1783632276803">
   <link rel="alternate" type="application/rss+xml" title="KST4Contest News" href="/feed.xml">
 
 <meta property="og:image" content="https://kst4contest.hamradioonline.de/assets/social/kst4contest-og.png">

website/_site/features/timeline/index.html

@@ -17,7 +17,7 @@
   <meta name="twitter:title" content="Timeline View">
   <meta name="twitter:description" content="The timeline view helps operators understand short propagation windows and candidate timing during active contest operation.">
 
-  <link rel="stylesheet" href="/assets/css/main.css?v=1783615687631">
+  <link rel="stylesheet" href="/assets/css/main.css?v=1783632276803">
   <link rel="alternate" type="application/rss+xml" title="KST4Contest News" href="/feed.xml">
 
 <meta property="og:image" content="https://kst4contest.hamradioonline.de/assets/social/kst4contest-og.png">

website/_site/index.html

@@ -17,7 +17,7 @@
   <meta name="twitter:title" content="KST4Contest – Contest-Optimized ON4KST Chat Client">
   <meta name="twitter:description" content="KST4Contest is a modern ON4KST chat client built for VHF, UHF and SHF contest operation.">
 
-  <link rel="stylesheet" href="/assets/css/main.css?v=1783615687631">
+  <link rel="stylesheet" href="/assets/css/main.css?v=1783632276803">
   <link rel="alternate" type="application/rss+xml" title="KST4Contest News" href="/feed.xml">
 
 <meta property="og:image" content="https://kst4contest.hamradioonline.de/assets/social/kst4contest-og.png">

website/_site/legal-notice/index.html

@@ -17,7 +17,7 @@
   <meta name="twitter:title" content="Legal Notice | KST4Contest">
   <meta name="twitter:description" content="Legal notice for the KST4Contest website.">
 
-  <link rel="stylesheet" href="/assets/css/main.css?v=1783615687631">
+  <link rel="stylesheet" href="/assets/css/main.css?v=1783632276803">
   <link rel="alternate" type="application/rss+xml" title="KST4Contest News" href="/feed.xml">
 
 <meta property="og:image" content="https://kst4contest.hamradioonline.de/assets/social/kst4contest-og.png">

website/_site/manual/de/airscout-integration/index.html

@@ -17,7 +17,7 @@
   <meta name="twitter:title" content="{{ manual.title }} | KST4Contest Manual">
   <meta name="twitter:description" content="KST4Contest manual page: {{ manual.title }}">
 
-  <link rel="stylesheet" href="/assets/css/main.css?v=1783615687631">
+  <link rel="stylesheet" href="/assets/css/main.css?v=1783632276803">
   <link rel="alternate" type="application/rss+xml" title="KST4Contest News" href="/feed.xml">
 
 <meta property="og:image" content="https://kst4contest.hamradioonline.de/assets/social/kst4contest-og.png">

website/_site/manual/de/benutzeroberflaeche/index.html

@@ -17,7 +17,7 @@
   <meta name="twitter:title" content="{{ manual.title }} | KST4Contest Manual">
   <meta name="twitter:description" content="KST4Contest manual page: {{ manual.title }}">
 
-  <link rel="stylesheet" href="/assets/css/main.css?v=1783615687631">
+  <link rel="stylesheet" href="/assets/css/main.css?v=1783632276803">
   <link rel="alternate" type="application/rss+xml" title="KST4Contest News" href="/feed.xml">
 
 <meta property="og:image" content="https://kst4contest.hamradioonline.de/assets/social/kst4contest-og.png">

website/_site/manual/de/changelog/index.html

@@ -17,7 +17,7 @@
   <meta name="twitter:title" content="{{ manual.title }} | KST4Contest Manual">
   <meta name="twitter:description" content="KST4Contest manual page: {{ manual.title }}">
 
-  <link rel="stylesheet" href="/assets/css/main.css?v=1783615687631">
+  <link rel="stylesheet" href="/assets/css/main.css?v=1783632276803">
   <link rel="alternate" type="application/rss+xml" title="KST4Contest News" href="/feed.xml">
 
 <meta property="og:image" content="https://kst4contest.hamradioonline.de/assets/social/kst4contest-og.png">

website/_site/manual/de/dx-cluster-server/index.html

@@ -17,7 +17,7 @@
   <meta name="twitter:title" content="{{ manual.title }} | KST4Contest Manual">
   <meta name="twitter:description" content="KST4Contest manual page: {{ manual.title }}">
 
-  <link rel="stylesheet" href="/assets/css/main.css?v=1783615687631">
+  <link rel="stylesheet" href="/assets/css/main.css?v=1783632276803">
   <link rel="alternate" type="application/rss+xml" title="KST4Contest News" href="/feed.xml">
 
 <meta property="og:image" content="https://kst4contest.hamradioonline.de/assets/social/kst4contest-og.png">

website/_site/manual/de/funktionen/index.html

@@ -17,7 +17,7 @@
   <meta name="twitter:title" content="{{ manual.title }} | KST4Contest Manual">
   <meta name="twitter:description" content="KST4Contest manual page: {{ manual.title }}">
 
-  <link rel="stylesheet" href="/assets/css/main.css?v=1783615687631">
+  <link rel="stylesheet" href="/assets/css/main.css?v=1783632276803">
   <link rel="alternate" type="application/rss+xml" title="KST4Contest News" href="/feed.xml">
 
 <meta property="og:image" content="https://kst4contest.hamradioonline.de/assets/social/kst4contest-og.png">

website/_site/manual/de/home/index.html

@@ -17,7 +17,7 @@
   <meta name="twitter:title" content="{{ manual.title }} | KST4Contest Manual">
   <meta name="twitter:description" content="KST4Contest manual page: {{ manual.title }}">
 
-  <link rel="stylesheet" href="/assets/css/main.css?v=1783615687631">
+  <link rel="stylesheet" href="/assets/css/main.css?v=1783632276803">
   <link rel="alternate" type="application/rss+xml" title="KST4Contest News" href="/feed.xml">
 
 <meta property="og:image" content="https://kst4contest.hamradioonline.de/assets/social/kst4contest-og.png">

website/_site/manual/de/index.html

@@ -17,7 +17,7 @@
   <meta name="twitter:title" content="KST4Contest Deutsches Handbuch">
   <meta name="twitter:description" content="Deutsches Benutzerhandbuch für KST4Contest.">
 
-  <link rel="stylesheet" href="/assets/css/main.css?v=1783615687631">
+  <link rel="stylesheet" href="/assets/css/main.css?v=1783632276803">
   <link rel="alternate" type="application/rss+xml" title="KST4Contest News" href="/feed.xml">
 
 <meta property="og:image" content="https://kst4contest.hamradioonline.de/assets/social/kst4contest-og.png">

website/_site/manual/de/installation/index.html

@@ -17,7 +17,7 @@
   <meta name="twitter:title" content="{{ manual.title }} | KST4Contest Manual">
   <meta name="twitter:description" content="KST4Contest manual page: {{ manual.title }}">
 
-  <link rel="stylesheet" href="/assets/css/main.css?v=1783615687631">
+  <link rel="stylesheet" href="/assets/css/main.css?v=1783632276803">
   <link rel="alternate" type="application/rss+xml" title="KST4Contest News" href="/feed.xml">
 
 <meta property="og:image" content="https://kst4contest.hamradioonline.de/assets/social/kst4contest-og.png">

website/_site/manual/de/konfiguration/index.html

@@ -17,7 +17,7 @@
   <meta name="twitter:title" content="{{ manual.title }} | KST4Contest Manual">
   <meta name="twitter:description" content="KST4Contest manual page: {{ manual.title }}">
 
-  <link rel="stylesheet" href="/assets/css/main.css?v=1783615687631">
+  <link rel="stylesheet" href="/assets/css/main.css?v=1783632276803">
   <link rel="alternate" type="application/rss+xml" title="KST4Contest News" href="/feed.xml">
 
 <meta property="og:image" content="https://kst4contest.hamradioonline.de/assets/social/kst4contest-og.png">

website/_site/manual/de/log-synchronisation/index.html

@@ -17,7 +17,7 @@
   <meta name="twitter:title" content="{{ manual.title }} | KST4Contest Manual">
   <meta name="twitter:description" content="KST4Contest manual page: {{ manual.title }}">
 
-  <link rel="stylesheet" href="/assets/css/main.css?v=1783615687631">
+  <link rel="stylesheet" href="/assets/css/main.css?v=1783632276803">
   <link rel="alternate" type="application/rss+xml" title="KST4Contest News" href="/feed.xml">
 
 <meta property="og:image" content="https://kst4contest.hamradioonline.de/assets/social/kst4contest-og.png">

website/_site/manual/de/makros-und-variablen/index.html

@@ -17,7 +17,7 @@
   <meta name="twitter:title" content="{{ manual.title }} | KST4Contest Manual">
   <meta name="twitter:description" content="KST4Contest manual page: {{ manual.title }}">
 
-  <link rel="stylesheet" href="/assets/css/main.css?v=1783615687631">
+  <link rel="stylesheet" href="/assets/css/main.css?v=1783632276803">
   <link rel="alternate" type="application/rss+xml" title="KST4Contest News" href="/feed.xml">
 
 <meta property="og:image" content="https://kst4contest.hamradioonline.de/assets/social/kst4contest-og.png">

website/_site/manual/en/airscout-integration/index.html

@@ -17,7 +17,7 @@
   <meta name="twitter:title" content="{{ manual.title }} | KST4Contest Manual">
   <meta name="twitter:description" content="KST4Contest manual page: {{ manual.title }}">
 
-  <link rel="stylesheet" href="/assets/css/main.css?v=1783615687631">
+  <link rel="stylesheet" href="/assets/css/main.css?v=1783632276803">
   <link rel="alternate" type="application/rss+xml" title="KST4Contest News" href="/feed.xml">
 
 <meta property="og:image" content="https://kst4contest.hamradioonline.de/assets/social/kst4contest-og.png">

website/_site/manual/en/changelog/index.html

@@ -17,7 +17,7 @@
   <meta name="twitter:title" content="{{ manual.title }} | KST4Contest Manual">
   <meta name="twitter:description" content="KST4Contest manual page: {{ manual.title }}">
 
-  <link rel="stylesheet" href="/assets/css/main.css?v=1783615687631">
+  <link rel="stylesheet" href="/assets/css/main.css?v=1783632276803">
   <link rel="alternate" type="application/rss+xml" title="KST4Contest News" href="/feed.xml">
 
 <meta property="og:image" content="https://kst4contest.hamradioonline.de/assets/social/kst4contest-og.png">

website/_site/manual/en/configuration/index.html

@@ -17,7 +17,7 @@
   <meta name="twitter:title" content="{{ manual.title }} | KST4Contest Manual">
   <meta name="twitter:description" content="KST4Contest manual page: {{ manual.title }}">
 
-  <link rel="stylesheet" href="/assets/css/main.css?v=1783615687631">
+  <link rel="stylesheet" href="/assets/css/main.css?v=1783632276803">
   <link rel="alternate" type="application/rss+xml" title="KST4Contest News" href="/feed.xml">
 
 <meta property="og:image" content="https://kst4contest.hamradioonline.de/assets/social/kst4contest-og.png">

website/_site/manual/en/dx-cluster-server/index.html

@@ -17,7 +17,7 @@
   <meta name="twitter:title" content="{{ manual.title }} | KST4Contest Manual">
   <meta name="twitter:description" content="KST4Contest manual page: {{ manual.title }}">
 
-  <link rel="stylesheet" href="/assets/css/main.css?v=1783615687631">
+  <link rel="stylesheet" href="/assets/css/main.css?v=1783632276803">
   <link rel="alternate" type="application/rss+xml" title="KST4Contest News" href="/feed.xml">
 
 <meta property="og:image" content="https://kst4contest.hamradioonline.de/assets/social/kst4contest-og.png">

website/_site/manual/en/features/index.html

@@ -17,7 +17,7 @@
   <meta name="twitter:title" content="{{ manual.title }} | KST4Contest Manual">
   <meta name="twitter:description" content="KST4Contest manual page: {{ manual.title }}">
 
-  <link rel="stylesheet" href="/assets/css/main.css?v=1783615687631">
+  <link rel="stylesheet" href="/assets/css/main.css?v=1783632276803">
   <link rel="alternate" type="application/rss+xml" title="KST4Contest News" href="/feed.xml">
 
 <meta property="og:image" content="https://kst4contest.hamradioonline.de/assets/social/kst4contest-og.png">

website/_site/manual/en/home/index.html

@@ -17,7 +17,7 @@
   <meta name="twitter:title" content="{{ manual.title }} | KST4Contest Manual">
   <meta name="twitter:description" content="KST4Contest manual page: {{ manual.title }}">
 
-  <link rel="stylesheet" href="/assets/css/main.css?v=1783615687631">
+  <link rel="stylesheet" href="/assets/css/main.css?v=1783632276803">
   <link rel="alternate" type="application/rss+xml" title="KST4Contest News" href="/feed.xml">
 
 <meta property="og:image" content="https://kst4contest.hamradioonline.de/assets/social/kst4contest-og.png">

website/_site/manual/en/index.html

@@ -17,7 +17,7 @@
   <meta name="twitter:title" content="KST4Contest English Manual">
   <meta name="twitter:description" content="English user manual for KST4Contest.">
 
-  <link rel="stylesheet" href="/assets/css/main.css?v=1783615687631">
+  <link rel="stylesheet" href="/assets/css/main.css?v=1783632276803">
   <link rel="alternate" type="application/rss+xml" title="KST4Contest News" href="/feed.xml">
 
 <meta property="og:image" content="https://kst4contest.hamradioonline.de/assets/social/kst4contest-og.png">

website/_site/manual/en/installation/index.html

@@ -17,7 +17,7 @@
   <meta name="twitter:title" content="{{ manual.title }} | KST4Contest Manual">
   <meta name="twitter:description" content="KST4Contest manual page: {{ manual.title }}">
 
-  <link rel="stylesheet" href="/assets/css/main.css?v=1783615687631">
+  <link rel="stylesheet" href="/assets/css/main.css?v=1783632276803">
   <link rel="alternate" type="application/rss+xml" title="KST4Contest News" href="/feed.xml">
 
 <meta property="og:image" content="https://kst4contest.hamradioonline.de/assets/social/kst4contest-og.png">

website/_site/manual/en/log-sync/index.html

@@ -17,7 +17,7 @@
   <meta name="twitter:title" content="{{ manual.title }} | KST4Contest Manual">
   <meta name="twitter:description" content="KST4Contest manual page: {{ manual.title }}">
 
-  <link rel="stylesheet" href="/assets/css/main.css?v=1783615687631">
+  <link rel="stylesheet" href="/assets/css/main.css?v=1783632276803">
   <link rel="alternate" type="application/rss+xml" title="KST4Contest News" href="/feed.xml">
 
 <meta property="og:image" content="https://kst4contest.hamradioonline.de/assets/social/kst4contest-og.png">

website/_site/manual/en/macros-and-variables/index.html

@@ -17,7 +17,7 @@
   <meta name="twitter:title" content="{{ manual.title }} | KST4Contest Manual">
   <meta name="twitter:description" content="KST4Contest manual page: {{ manual.title }}">
 
-  <link rel="stylesheet" href="/assets/css/main.css?v=1783615687631">
+  <link rel="stylesheet" href="/assets/css/main.css?v=1783632276803">
   <link rel="alternate" type="application/rss+xml" title="KST4Contest News" href="/feed.xml">
 
 <meta property="og:image" content="https://kst4contest.hamradioonline.de/assets/social/kst4contest-og.png">

website/_site/manual/en/user-interface/index.html

@@ -17,7 +17,7 @@
   <meta name="twitter:title" content="{{ manual.title }} | KST4Contest Manual">
   <meta name="twitter:description" content="KST4Contest manual page: {{ manual.title }}">
 
-  <link rel="stylesheet" href="/assets/css/main.css?v=1783615687631">
+  <link rel="stylesheet" href="/assets/css/main.css?v=1783632276803">
   <link rel="alternate" type="application/rss+xml" title="KST4Contest News" href="/feed.xml">
 
 <meta property="og:image" content="https://kst4contest.hamradioonline.de/assets/social/kst4contest-og.png">

website/_site/manual/index.html

@@ -17,7 +17,7 @@
   <meta name="twitter:title" content="KST4Contest Manual">
   <meta name="twitter:description" content="Online manual for KST4Contest, the contest-optimized ON4KST chat client.">
 
-  <link rel="stylesheet" href="/assets/css/main.css?v=1783615687631">
+  <link rel="stylesheet" href="/assets/css/main.css?v=1783632276803">
   <link rel="alternate" type="application/rss+xml" title="KST4Contest News" href="/feed.xml">
 
 <meta property="og:image" content="https://kst4contest.hamradioonline.de/assets/social/kst4contest-og.png">

website/_site/news/2026-07-08-hotfix-version-1-41-1/index.html

@@ -17,7 +17,7 @@
   <meta name="twitter:title" content="Hotfix Version 1.41.1">
   <meta name="twitter:description" content="Contest-optimized ON4KST chat client for VHF, UHF and SHF ham radio contests.">
 
-  <link rel="stylesheet" href="/assets/css/main.css?v=1783615687631">
+  <link rel="stylesheet" href="/assets/css/main.css?v=1783632276803">
   <link rel="alternate" type="application/rss+xml" title="KST4Contest News" href="/feed.xml">
 
 <meta property="og:image" content="https://kst4contest.hamradioonline.de/assets/social/kst4contest-og.png">

website/_site/news/2026-07-website-launch/index.html

@@ -17,7 +17,7 @@
   <meta name="twitter:title" content="KST4Contest Website Launch">
   <meta name="twitter:description" content="Contest-optimized ON4KST chat client for VHF, UHF and SHF ham radio contests.">
 
-  <link rel="stylesheet" href="/assets/css/main.css?v=1783615687631">
+  <link rel="stylesheet" href="/assets/css/main.css?v=1783632276803">
   <link rel="alternate" type="application/rss+xml" title="KST4Contest News" href="/feed.xml">
 
 <meta property="og:image" content="https://kst4contest.hamradioonline.de/assets/social/kst4contest-og.png">

website/_site/news/index.html

@@ -17,7 +17,7 @@
   <meta name="twitter:title" content="KST4Contest News">
   <meta name="twitter:description" content="News, release updates and development notes for KST4Contest.">
 
-  <link rel="stylesheet" href="/assets/css/main.css?v=1783615687631">
+  <link rel="stylesheet" href="/assets/css/main.css?v=1783632276803">
   <link rel="alternate" type="application/rss+xml" title="KST4Contest News" href="/feed.xml">
 
 <meta property="og:image" content="https://kst4contest.hamradioonline.de/assets/social/kst4contest-og.png">

website/_site/privacy/index.html

@@ -17,7 +17,7 @@
   <meta name="twitter:title" content="Privacy Policy | KST4Contest">
   <meta name="twitter:description" content="Privacy policy for the KST4Contest website.">
 
-  <link rel="stylesheet" href="/assets/css/main.css?v=1783615687631">
+  <link rel="stylesheet" href="/assets/css/main.css?v=1783632276803">
   <link rel="alternate" type="application/rss+xml" title="KST4Contest News" href="/feed.xml">
 
 <meta property="og:image" content="https://kst4contest.hamradioonline.de/assets/social/kst4contest-og.png">

website/_site/roadmap/index.html

@@ -17,7 +17,7 @@
   <meta name="twitter:title" content="KST4Contest Roadmap">
   <meta name="twitter:description" content="Planned enhancements for upcoming KST4Contest versions, generated from GitHub milestones and issues.">
 
-  <link rel="stylesheet" href="/assets/css/main.css?v=1783615687631">
+  <link rel="stylesheet" href="/assets/css/main.css?v=1783632276803">
   <link rel="alternate" type="application/rss+xml" title="KST4Contest News" href="/feed.xml">
 
 <meta property="og:image" content="https://kst4contest.hamradioonline.de/assets/social/kst4contest-og.png">
@@ -148,6 +148,10 @@
       
       <ul>
         
+          <li>
+            <a href="https://github.com/praktimarc/kst4contest/issues/59">[FEATURE] window control</a>
+          </li>
+        
           <li>
             <a href="https://github.com/praktimarc/kst4contest/issues/55">[FEATURE] Reset-Button for the map</a>
           </li>

website/_site/screenshots/index.html

@@ -17,7 +17,7 @@
   <meta name="twitter:title" content="KST4Contest Screenshots">
   <meta name="twitter:description" content="Screenshots of KST4Contest, the contest-optimized ON4KST chat client for VHF, UHF and SHF operators.">
 
-  <link rel="stylesheet" href="/assets/css/main.css?v=1783615687631">
+  <link rel="stylesheet" href="/assets/css/main.css?v=1783632276803">
   <link rel="alternate" type="application/rss+xml" title="KST4Contest News" href="/feed.xml">
 
 <meta property="og:image" content="https://kst4contest.hamradioonline.de/assets/social/kst4contest-og.png">

website/src/_data/navigation.js

@@ -6,5 +6,7 @@ module.exports = [
     { title: "News", url: "/news/" },
     { title: "Roadmap", url: "/roadmap/" },
     { title: "About", url: "/about/" },
-    { title: "FAQ", url: "/faq/" }
+    { title: "FAQ", url: "/faq/" },
+    { title: "Support", url: "/support/"
+    }
 ];

website/src/_layouts/base.njk

@@ -71,6 +71,7 @@
         <p><a href="https://github.com/praktimarc/kst4contest">GitHub Repository</a></p>
         <p><a href="https://github.com/praktimarc/kst4contest/issues">Issues</a></p>
         <p><a href="/contact/">Contact</a></p>
+        <p><a href="/support/">❤️ Support KST4Contest</a></p>
       </div>
 
       <div>
@@ -80,5 +81,10 @@
       </div>
     </div>
   </footer>
+
+  {% if heroFx %}
+    <script src="/assets/js/hero-radio-fx.js?v={{ build.version }}" defer></script>
+  {% endif %}
+
 </body>
 </html>

website/src/about/index.njk

@@ -26,5 +26,20 @@ description: About KST4Contest and its contest-oriented ON4KST workflow.
       The project is open source and focused on practical contest station workflows.
       Features are designed around real operating pressure, not theoretical UI concepts.
     </p>
+
+    <h2>Community supported</h2>
+
+    <p>
+
+    KST4Contest is developed independently.
+
+    Community support helps finance hosting,
+    online services,
+    testing across multiple operating systems
+    and future contest-oriented features.
+
+    </p>
+
   </article>
+
 </section>

website/src/assets/css/main.css

@@ -7,10 +7,22 @@
     --text: #f8fafc;
     --muted: #aab6ca;
     --soft: #64748b;
-    --accent: #38bdf8;
+    /*--accent: #38bdf8;*/
-    --accent2: #a855f7;
+    /*--accent2: #a855f7;*/
-    --accent3: #22c55e;
+    /*--accent3: #22c55e;*/
     --shadow: 0 24px 80px rgba(0, 0, 0, 0.45);
+
+    --accent: #54d63d;
+    --accent2: #8aef64;
+    --accent3: #31b54a;
+
+    --fx-plane: #79ff73;
+    --fx-plane-muted: rgba(121, 255, 115, 0.42);
+    --fx-beam: #52ff65;
+    --fx-beam-glow: rgba(82, 255, 101, 0.28);
+    --fx-reflection: #d2ffc8;
+    --fx-trail: rgba(121, 255, 115, 0.17);
+    --fx-grid: rgba(121, 255, 115, 0.055);
 }
 
 * {
@@ -25,13 +37,39 @@ html {
 body {
     margin: 0;
     min-height: 100vh;
+
     background:
-            radial-gradient(circle at 14% 12%, rgba(168, 85, 247, 0.30), transparent 28%),
+            radial-gradient(
-            radial-gradient(circle at 82% 16%, rgba(56, 189, 248, 0.24), transparent 30%),
+                    circle at 14% 12%,
-            radial-gradient(circle at 50% 85%, rgba(34, 197, 94, 0.11), transparent 35%),
+                    rgba(52, 165, 57, 0.20),
-            linear-gradient(180deg, #050816 0%, #07111f 100%);
+                    transparent 30%
+            ),
+            radial-gradient(
+                    circle at 82% 16%,
+                    rgba(95, 218, 82, 0.14),
+                    transparent 32%
+            ),
+            radial-gradient(
+                    circle at 50% 85%,
+                    rgba(32, 126, 55, 0.12),
+                    transparent 36%
+            ),
+            linear-gradient(
+                    180deg,
+                    #070b09 0%,
+                    #0b1410 100%
+            );
+
     color: var(--text);
-    font-family: Inter, ui-sans-serif, system-ui, -apple-system, BlinkMacSystemFont, "Segoe UI", sans-serif;
+    font-family:
+            Inter,
+            ui-sans-serif,
+            system-ui,
+            -apple-system,
+            BlinkMacSystemFont,
+            "Segoe UI",
+            sans-serif;
+
     line-height: 1.65;
     overflow-x: hidden;
 }
@@ -562,3 +600,155 @@ a:hover {
         grid-template-columns: 1fr;
     }
 }
+
+/*
+ * Interactive radio / aircraft-scatter hero layer
+ */
+
+.hero-radio-fx {
+    position: absolute;
+    inset: 0;
+    z-index: 0;
+    width: 100%;
+    height: 100%;
+    pointer-events: none;
+    opacity: 0.76;
+}
+
+.hero-fx-vignette {
+    position: absolute;
+    inset: 0;
+    z-index: 1;
+    pointer-events: none;
+
+    background:
+            linear-gradient(
+                    90deg,
+                    rgba(7, 11, 9, 0.92) 0%,
+                    rgba(7, 11, 9, 0.68) 34%,
+                    rgba(7, 11, 9, 0.16) 64%,
+                    rgba(7, 11, 9, 0.42) 100%
+            ),
+            linear-gradient(
+                    180deg,
+                    rgba(7, 11, 9, 0.10),
+                    rgba(7, 11, 9, 0.58)
+            );
+}
+
+.hero-split > *:not(.hero-radio-fx):not(.hero-fx-vignette) {
+    position: relative;
+    z-index: 2;
+}
+
+/*
+ * Operator-console badge styling
+ */
+
+.badge,
+.eyebrow {
+    color: #caffc0;
+    background: rgba(52, 165, 57, 0.12);
+    border-color: rgba(105, 232, 88, 0.32);
+    box-shadow: 0 0 22px rgba(82, 255, 101, 0.08);
+}
+
+/*
+ * Light-mode identity:
+ * white/grey UI with red contest accents
+ */
+
+html[data-theme="light"] {
+    --bg: #f4f4f2;
+    --bg2: #ffffff;
+    --panel: rgba(255, 255, 255, 0.88);
+    --panel2: rgba(242, 242, 239, 0.92);
+    --border: rgba(91, 91, 86, 0.20);
+    --text: #252522;
+    --muted: #656560;
+    --soft: #888881;
+
+    --accent: #d33732;
+    --accent2: #f25a51;
+    --accent3: #ae2727;
+
+    --fx-plane: #df3732;
+    --fx-plane-muted: rgba(211, 55, 50, 0.38);
+    --fx-beam: #ef4039;
+    --fx-beam-glow: rgba(239, 64, 57, 0.22);
+    --fx-reflection: #ff8d84;
+    --fx-trail: rgba(211, 55, 50, 0.15);
+    --fx-grid: rgba(185, 47, 43, 0.045);
+}
+
+html[data-theme="light"] body {
+    background:
+            radial-gradient(
+                    circle at 14% 12%,
+                    rgba(211, 55, 50, 0.12),
+                    transparent 30%
+            ),
+            radial-gradient(
+                    circle at 82% 16%,
+                    rgba(242, 90, 81, 0.09),
+                    transparent 32%
+            ),
+            linear-gradient(
+                    180deg,
+                    #ffffff 0%,
+                    #f0f0ed 100%
+            );
+}
+
+html[data-theme="light"] .hero-fx-vignette {
+    background:
+            linear-gradient(
+                    90deg,
+                    rgba(255, 255, 255, 0.95) 0%,
+                    rgba(255, 255, 255, 0.76) 34%,
+                    rgba(255, 255, 255, 0.18) 66%,
+                    rgba(255, 255, 255, 0.48) 100%
+            ),
+            linear-gradient(
+                    180deg,
+                    rgba(255, 255, 255, 0.06),
+                    rgba(240, 240, 237, 0.62)
+            );
+}
+
+html[data-theme="light"] .badge,
+html[data-theme="light"] .eyebrow {
+    color: #962a27;
+    background: rgba(211, 55, 50, 0.08);
+    border-color: rgba(211, 55, 50, 0.24);
+}
+
+@media (max-width: 900px) {
+    .hero-radio-fx {
+        opacity: 0.48;
+    }
+
+    .hero-fx-vignette {
+        background:
+                linear-gradient(
+                        180deg,
+                        rgba(7, 11, 9, 0.82),
+                        rgba(7, 11, 9, 0.34)
+                );
+    }
+
+    html[data-theme="light"] .hero-fx-vignette {
+        background:
+                linear-gradient(
+                        180deg,
+                        rgba(255, 255, 255, 0.90),
+                        rgba(255, 255, 255, 0.42)
+                );
+    }
+}
+
+@media (prefers-reduced-motion: reduce) {
+    .hero-radio-fx {
+        opacity: 0.28;
+    }
+}

website/src/assets/js/hero-radio-fx.js

@@ -0,0 +1,710 @@
+(() => {
+    "use strict";
+
+    const canvas = document.querySelector("[data-hero-radio-fx]");
+
+    if (!(canvas instanceof HTMLCanvasElement)) {
+        return;
+    }
+
+    const context = canvas.getContext("2d", {
+        alpha: true,
+        desynchronized: true
+    });
+
+    if (!context) {
+        return;
+    }
+
+    const hero = canvas.closest(".hero");
+
+    if (!(hero instanceof HTMLElement)) {
+        return;
+    }
+
+    const reducedMotion = window.matchMedia(
+        "(prefers-reduced-motion: reduce)"
+    );
+
+    const coarsePointer = window.matchMedia(
+        "(pointer: coarse)"
+    );
+
+    const state = {
+        width: 0,
+        height: 0,
+        dpr: 1,
+        running: false,
+        visible: true,
+        lastFrame: 0,
+        spawnAccumulator: 0,
+        beamAccumulator: 0,
+        animationFrameId: 0,
+        pointer: {
+            x: 0,
+            y: 0,
+            active: false
+        },
+        planes: [],
+        beams: [],
+        reflections: []
+    };
+
+    const clamp = (value, minimum, maximum) =>
+        Math.max(minimum, Math.min(maximum, value));
+
+    const randomBetween = (minimum, maximum) =>
+        minimum + Math.random() * (maximum - minimum);
+
+    function getCssColor(name, fallback) {
+        const value = getComputedStyle(document.documentElement)
+            .getPropertyValue(name)
+            .trim();
+
+        return value || fallback;
+    }
+
+    function getPalette() {
+        return {
+            plane: getCssColor("--fx-plane", "#79ff73"),
+            planeMuted: getCssColor("--fx-plane-muted", "rgba(121,255,115,.42)"),
+            beam: getCssColor("--fx-beam", "#52ff65"),
+            beamGlow: getCssColor("--fx-beam-glow", "rgba(82,255,101,.28)"),
+            reflection: getCssColor("--fx-reflection", "#c8ffbf"),
+            trail: getCssColor("--fx-trail", "rgba(121,255,115,.16)"),
+            grid: getCssColor("--fx-grid", "rgba(121,255,115,.055)")
+        };
+    }
+
+    function resizeCanvas() {
+        const bounds = hero.getBoundingClientRect();
+
+        state.width = Math.max(1, Math.round(bounds.width));
+        state.height = Math.max(1, Math.round(bounds.height));
+        state.dpr = Math.min(window.devicePixelRatio || 1, 1.5);
+
+        canvas.width = Math.round(state.width * state.dpr);
+        canvas.height = Math.round(state.height * state.dpr);
+
+        canvas.style.width = `${state.width}px`;
+        canvas.style.height = `${state.height}px`;
+
+        context.setTransform(
+            state.dpr,
+            0,
+            0,
+            state.dpr,
+            0,
+            0
+        );
+
+        if (!state.pointer.active) {
+            state.pointer.x = state.width * 0.54;
+            state.pointer.y = state.height * 0.42;
+        }
+    }
+
+    function getPlaneLimit() {
+        if (coarsePointer.matches) {
+            return 5;
+        }
+
+        if (state.width < 900) {
+            return 7;
+        }
+
+        return 12;
+    }
+
+    function createPlane() {
+        const margin = 55;
+        const edge = Math.floor(Math.random() * 4);
+
+        let x;
+        let y;
+
+        switch (edge) {
+            case 0:
+                x = randomBetween(0, state.width);
+                y = -margin;
+                break;
+
+            case 1:
+                x = state.width + margin;
+                y = randomBetween(0, state.height);
+                break;
+
+            case 2:
+                x = randomBetween(0, state.width);
+                y = state.height + margin;
+                break;
+
+            default:
+                x = -margin;
+                y = randomBetween(0, state.height);
+                break;
+        }
+
+        const targetX = state.pointer.active
+            ? state.pointer.x
+            : state.width * randomBetween(0.38, 0.72);
+
+        const targetY = state.pointer.active
+            ? state.pointer.y
+            : state.height * randomBetween(0.2, 0.72);
+
+        const angle = Math.atan2(targetY - y, targetX - x);
+        const speed = randomBetween(18, 34);
+
+        return {
+            x,
+            y,
+            previousX: x,
+            previousY: y,
+            velocityX: Math.cos(angle) * speed,
+            velocityY: Math.sin(angle) * speed,
+            angle,
+            size: randomBetween(5.5, 9),
+            age: 0,
+            maximumAge: randomBetween(12, 20),
+            steering: randomBetween(0.65, 1.2),
+            wobble: randomBetween(0, Math.PI * 2),
+            wobbleSpeed: randomBetween(0.7, 1.4),
+            hit: 0
+        };
+    }
+
+    function updatePlane(plane, deltaSeconds) {
+        plane.age += deltaSeconds;
+        plane.wobble += deltaSeconds * plane.wobbleSpeed;
+
+        plane.previousX = plane.x;
+        plane.previousY = plane.y;
+
+        const targetX = state.pointer.active
+            ? state.pointer.x
+            : state.width * 0.56;
+
+        const targetY = state.pointer.active
+            ? state.pointer.y
+            : state.height * 0.44;
+
+        const desiredAngle = Math.atan2(
+            targetY - plane.y,
+            targetX - plane.x
+        );
+
+        let angleDifference = desiredAngle - plane.angle;
+
+        while (angleDifference > Math.PI) {
+            angleDifference -= Math.PI * 2;
+        }
+
+        while (angleDifference < -Math.PI) {
+            angleDifference += Math.PI * 2;
+        }
+
+        plane.angle += angleDifference * plane.steering * deltaSeconds;
+
+        const speed = Math.hypot(
+            plane.velocityX,
+            plane.velocityY
+        );
+
+        const wobble = Math.sin(plane.wobble) * 0.14;
+
+        plane.velocityX =
+            Math.cos(plane.angle + wobble) * speed;
+
+        plane.velocityY =
+            Math.sin(plane.angle + wobble) * speed;
+
+        plane.x += plane.velocityX * deltaSeconds;
+        plane.y += plane.velocityY * deltaSeconds;
+
+        plane.hit = Math.max(0, plane.hit - deltaSeconds * 1.8);
+    }
+
+    function isPlaneExpired(plane) {
+        const margin = 180;
+
+        return (
+            plane.age > plane.maximumAge ||
+            plane.x < -margin ||
+            plane.x > state.width + margin ||
+            plane.y < -margin ||
+            plane.y > state.height + margin
+        );
+    }
+
+    function chooseBeamTarget() {
+        if (state.planes.length === 0) {
+            return null;
+        }
+
+        const targetX = state.pointer.active
+            ? state.pointer.x
+            : state.width * 0.56;
+
+        const targetY = state.pointer.active
+            ? state.pointer.y
+            : state.height * 0.44;
+
+        const candidates = state.planes
+            .map((plane) => ({
+                plane,
+                distance: Math.hypot(
+                    plane.x - targetX,
+                    plane.y - targetY
+                )
+            }))
+            .filter((entry) => entry.distance < 260)
+            .sort((a, b) => a.distance - b.distance);
+
+        if (candidates.length > 0) {
+            return candidates[0].plane;
+        }
+
+        return state.planes[
+            Math.floor(Math.random() * state.planes.length)
+            ];
+    }
+
+    function createBeam(target) {
+        const leftStation = {
+            x: state.width * 0.12,
+            y: state.height * 0.82
+        };
+
+        const rightStation = {
+            x: state.width * 0.88,
+            y: state.height * 0.78
+        };
+
+        const source =
+            Math.abs(target.x - leftStation.x) <
+            Math.abs(target.x - rightStation.x)
+                ? leftStation
+                : rightStation;
+
+        state.beams.push({
+            startX: source.x,
+            startY: source.y,
+            endX: target.x,
+            endY: target.y,
+            age: 0,
+            maximumAge: 0.62
+        });
+
+        target.hit = 1;
+
+        state.reflections.push({
+            x: target.x,
+            y: target.y,
+            age: 0,
+            maximumAge: 0.9,
+            radius: randomBetween(8, 15)
+        });
+    }
+
+    function updateEffects(deltaSeconds) {
+        for (const beam of state.beams) {
+            beam.age += deltaSeconds;
+        }
+
+        state.beams = state.beams.filter(
+            (beam) => beam.age < beam.maximumAge
+        );
+
+        for (const reflection of state.reflections) {
+            reflection.age += deltaSeconds;
+            reflection.radius += deltaSeconds * 30;
+        }
+
+        state.reflections = state.reflections.filter(
+            (reflection) =>
+                reflection.age < reflection.maximumAge
+        );
+    }
+
+    function drawGrid(palette) {
+        context.save();
+
+        context.strokeStyle = palette.grid;
+        context.lineWidth = 1;
+
+        const spacing = 54;
+
+        for (
+            let x = spacing;
+            x < state.width;
+            x += spacing
+        ) {
+            context.beginPath();
+            context.moveTo(x, 0);
+            context.lineTo(x, state.height);
+            context.stroke();
+        }
+
+        for (
+            let y = spacing;
+            y < state.height;
+            y += spacing
+        ) {
+            context.beginPath();
+            context.moveTo(0, y);
+            context.lineTo(state.width, y);
+            context.stroke();
+        }
+
+        context.restore();
+    }
+
+    function drawRadarTarget(palette) {
+        const x = state.pointer.active
+            ? state.pointer.x
+            : state.width * 0.56;
+
+        const y = state.pointer.active
+            ? state.pointer.y
+            : state.height * 0.44;
+
+        context.save();
+
+        context.strokeStyle = palette.planeMuted;
+        context.lineWidth = 1;
+
+        for (const radius of [24, 48, 82]) {
+            context.globalAlpha = 0.24 - radius / 500;
+
+            context.beginPath();
+            context.arc(x, y, radius, 0, Math.PI * 2);
+            context.stroke();
+        }
+
+        context.globalAlpha = 0.2;
+
+        context.beginPath();
+        context.moveTo(x - 100, y);
+        context.lineTo(x + 100, y);
+        context.moveTo(x, y - 100);
+        context.lineTo(x, y + 100);
+        context.stroke();
+
+        context.restore();
+    }
+
+    function drawPlane(plane, palette) {
+        context.save();
+
+        context.translate(plane.x, plane.y);
+        context.rotate(plane.angle);
+
+        const alpha = clamp(
+            Math.min(
+                plane.age * 1.8,
+                (plane.maximumAge - plane.age) * 1.8
+            ),
+            0,
+            1
+        );
+
+        context.globalAlpha = alpha;
+
+        context.strokeStyle = palette.trail;
+        context.lineWidth = 1;
+
+        context.beginPath();
+        context.moveTo(-plane.size * 4.5, 0);
+        context.lineTo(-plane.size * 1.4, 0);
+        context.stroke();
+
+        context.fillStyle =
+            plane.hit > 0
+                ? palette.reflection
+                : palette.plane;
+
+        context.shadowColor =
+            plane.hit > 0
+                ? palette.reflection
+                : palette.beamGlow;
+
+        context.shadowBlur =
+            plane.hit > 0
+                ? 16
+                : 5;
+
+        const size = plane.size;
+
+        context.beginPath();
+
+        context.moveTo(size * 1.65, 0);
+        context.lineTo(-size * 0.7, size * 0.34);
+        context.lineTo(-size * 0.15, size * 1.05);
+        context.lineTo(-size * 0.65, size * 1.08);
+        context.lineTo(-size * 1.35, size * 0.3);
+        context.lineTo(-size * 1.7, size * 0.28);
+        context.lineTo(-size * 1.12, 0);
+        context.lineTo(-size * 1.7, -size * 0.28);
+        context.lineTo(-size * 1.35, -size * 0.3);
+        context.lineTo(-size * 0.65, -size * 1.08);
+        context.lineTo(-size * 0.15, -size * 1.05);
+        context.lineTo(-size * 0.7, -size * 0.34);
+
+        context.closePath();
+        context.fill();
+
+        context.restore();
+    }
+
+    function drawBeam(beam, palette) {
+        const progress = beam.age / beam.maximumAge;
+        const alpha = Math.sin(progress * Math.PI);
+
+        context.save();
+
+        context.globalAlpha = alpha;
+        context.strokeStyle = palette.beamGlow;
+        context.lineWidth = 6;
+        context.shadowColor = palette.beam;
+        context.shadowBlur = 15;
+
+        context.beginPath();
+        context.moveTo(beam.startX, beam.startY);
+        context.lineTo(beam.endX, beam.endY);
+        context.stroke();
+
+        context.strokeStyle = palette.beam;
+        context.lineWidth = 1.4;
+        context.shadowBlur = 5;
+
+        context.beginPath();
+        context.moveTo(beam.startX, beam.startY);
+        context.lineTo(beam.endX, beam.endY);
+        context.stroke();
+
+        context.restore();
+    }
+
+    function drawReflection(reflection, palette) {
+        const progress =
+            reflection.age / reflection.maximumAge;
+
+        context.save();
+
+        context.globalAlpha = 1 - progress;
+        context.strokeStyle = palette.reflection;
+        context.lineWidth = 1.5;
+        context.shadowColor = palette.beam;
+        context.shadowBlur = 12;
+
+        context.beginPath();
+        context.arc(
+            reflection.x,
+            reflection.y,
+            reflection.radius,
+            0,
+            Math.PI * 2
+        );
+        context.stroke();
+
+        context.restore();
+    }
+
+    function drawStaticScene() {
+        const palette = getPalette();
+
+        context.clearRect(
+            0,
+            0,
+            state.width,
+            state.height
+        );
+
+        drawGrid(palette);
+        drawRadarTarget(palette);
+    }
+
+    function drawScene() {
+        const palette = getPalette();
+
+        context.clearRect(
+            0,
+            0,
+            state.width,
+            state.height
+        );
+
+        drawGrid(palette);
+        drawRadarTarget(palette);
+
+        for (const plane of state.planes) {
+            drawPlane(plane, palette);
+        }
+
+        for (const beam of state.beams) {
+            drawBeam(beam, palette);
+        }
+
+        for (const reflection of state.reflections) {
+            drawReflection(reflection, palette);
+        }
+    }
+
+    function animate(timestamp) {
+        if (!state.running) {
+            return;
+        }
+
+        const deltaSeconds = clamp(
+            (timestamp - state.lastFrame) / 1000 || 0,
+            0,
+            0.05
+        );
+
+        state.lastFrame = timestamp;
+
+        if (!state.visible || document.hidden) {
+            state.animationFrameId =
+                requestAnimationFrame(animate);
+
+            return;
+        }
+
+        state.spawnAccumulator += deltaSeconds;
+        state.beamAccumulator += deltaSeconds;
+
+        const planeLimit = getPlaneLimit();
+        const spawnInterval =
+            coarsePointer.matches ? 2.2 : 1.15;
+
+        if (
+            state.spawnAccumulator >= spawnInterval &&
+            state.planes.length < planeLimit
+        ) {
+            state.spawnAccumulator = 0;
+            state.planes.push(createPlane());
+        }
+
+        const beamInterval =
+            coarsePointer.matches ? 3.3 : 1.8;
+
+        if (
+            state.beamAccumulator >= beamInterval &&
+            state.planes.length > 0
+        ) {
+            state.beamAccumulator = 0;
+
+            const target = chooseBeamTarget();
+
+            if (target) {
+                createBeam(target);
+            }
+        }
+
+        for (const plane of state.planes) {
+            updatePlane(plane, deltaSeconds);
+        }
+
+        state.planes = state.planes.filter(
+            (plane) => !isPlaneExpired(plane)
+        );
+
+        updateEffects(deltaSeconds);
+        drawScene();
+
+        state.animationFrameId =
+            requestAnimationFrame(animate);
+    }
+
+    function start() {
+        cancelAnimationFrame(state.animationFrameId);
+
+        resizeCanvas();
+
+        if (reducedMotion.matches) {
+            state.running = false;
+            drawStaticScene();
+            return;
+        }
+
+        state.running = true;
+        state.lastFrame = performance.now();
+
+        if (state.planes.length === 0) {
+            const initialPlanes =
+                coarsePointer.matches ? 2 : 5;
+
+            for (let index = 0; index < initialPlanes; index++) {
+                const plane = createPlane();
+                plane.age = Math.random() * 2;
+                state.planes.push(plane);
+            }
+        }
+
+        state.animationFrameId =
+            requestAnimationFrame(animate);
+    }
+
+    function updatePointer(event) {
+        const bounds = hero.getBoundingClientRect();
+
+        state.pointer.x = clamp(
+            event.clientX - bounds.left,
+            0,
+            bounds.width
+        );
+
+        state.pointer.y = clamp(
+            event.clientY - bounds.top,
+            0,
+            bounds.height
+        );
+
+        state.pointer.active = true;
+    }
+
+    hero.addEventListener("pointermove", updatePointer, {
+        passive: true
+    });
+
+    hero.addEventListener("pointerleave", () => {
+        state.pointer.active = false;
+    });
+
+    window.addEventListener("resize", resizeCanvas, {
+        passive: true
+    });
+
+    document.addEventListener("visibilitychange", () => {
+        state.lastFrame = performance.now();
+    });
+
+    reducedMotion.addEventListener("change", start);
+
+    const resizeObserver = new ResizeObserver(() => {
+        resizeCanvas();
+
+        if (reducedMotion.matches) {
+            drawStaticScene();
+        }
+    });
+
+    resizeObserver.observe(hero);
+
+    const intersectionObserver = new IntersectionObserver(
+        (entries) => {
+            state.visible =
+                entries[0]?.isIntersecting ?? true;
+
+            state.lastFrame = performance.now();
+        },
+        {
+            threshold: 0.05
+        }
+    );
+
+    intersectionObserver.observe(hero);
+
+    start();
+})();

website/src/download/index.njk

@@ -57,3 +57,31 @@ description: Download KST4Contest releases for Windows, Linux and macOS.
     </div>
   </div>
 </section>
+
+<section class="section">
+
+    <div class="card content-card">
+
+        <h2>Enjoying KST4Contest?</h2>
+
+        <p>
+
+            If KST4Contest makes contesting easier for you,
+            please consider supporting future development.
+
+        </p>
+
+        <div class="actions">
+
+            <a class="button"
+               href="/support/">
+
+                ❤️ Support Development
+
+            </a>
+
+        </div>
+
+    </div>
+
+</section>

website/src/index.njk

@@ -2,9 +2,18 @@
 layout: base.njk
 title: KST4Contest – Contest-Optimized ON4KST Chat Client
 description: KST4Contest is a modern ON4KST chat client built for VHF, UHF and SHF contest operation.
+heroFx: true
 ---
 
 <section class="hero hero-split">
+
+  <canvas
+    class="hero-radio-fx"
+    data-hero-radio-fx
+    aria-hidden="true">
+  </canvas>
+
+  <div class="hero-fx-vignette" aria-hidden="true"></div>
   <div>
     <p class="badge">The contest-optimized ON4KST client</p>
     <h1>KST4Contest</h1>
@@ -73,6 +82,7 @@ description: KST4Contest is a modern ON4KST chat client built for VHF, UHF and S
     <div class="actions">
       <a class="button" href="/download/">Download KST4Contest</a>
       <a class="button secondary" href="/features/">Explore features</a>
+      <a class="button ghost" href="/support/">❤️ Support Development</a>
     </div>
   </div>
 </section>

website/src/privacy/index.njk

@@ -44,6 +44,22 @@ description: Privacy policy for the KST4Contest website.
       GitHub is responsible for its own data processing.
     </p>
 
+    <h2>
+
+    Support via Ko-fi
+
+    </h2>
+
+    <p>
+
+    This website links to Ko-fi for voluntary financial support.
+
+    Payments are processed entirely by Ko-fi and its payment providers.
+
+    KST4Contest itself never receives or processes payment information.
+
+    </p>
+
     <h2>Your rights</h2>
     <p>
       You may have the right to access, rectification, erasure, restriction of processing,

website/src/roadmap/index.njk

@@ -48,3 +48,46 @@ description: Planned enhancements for upcoming KST4Contest versions, generated f
     </article>
   {% endfor %}
 </section>
+
+<section class="section">
+
+<div class="cta-panel">
+
+<p class="eyebrow">
+
+Community
+
+</p>
+
+<h2>
+
+Development is driven by the community.
+
+</h2>
+
+<p>
+
+Many roadmap items require
+time,
+online services
+and infrastructure.
+
+Community support helps accelerate development.
+
+</p>
+
+<div class="actions">
+
+<a class="button"
+
+href="/support/">
+
+❤️ Support Development
+
+</a>
+
+</div>
+
+</div>
+
+</section>

website/src/support/index.njk

@@ -0,0 +1,176 @@
+---
+layout: base.njk
+title: Support KST4Contest
+description: Help support the ongoing development of KST4Contest.
+---
+
+<section class="hero">
+    <p class="badge">Support Development</p>
+
+    <h1>Help shape the future of KST4Contest.</h1>
+
+    <p class="lead">
+        KST4Contest is an independent open-source project developed in my free time.
+        Your support helps cover infrastructure costs and enables new contest-oriented
+        features that would otherwise be difficult to implement.
+    </p>
+
+    <div class="actions">
+        <a class="button"
+           href="https://ko-fi.com/praktimarc"
+           target="_blank"
+           rel="noopener">
+            ❤️ Support on Ko-fi
+        </a>
+
+        <a class="button secondary"
+           href="https://github.com/praktimarc/kst4contest">
+            View Source Code
+        </a>
+    </div>
+</section>
+
+
+<section class="section">
+
+<div class="section-heading">
+<p class="eyebrow">What previous support has enabled</p>
+
+<h2>Real improvements funded by the community.</h2>
+</div>
+
+<div class="grid">
+
+<article class="card">
+
+<h3>🛰 PSTRotator Integration</h3>
+
+<p>
+
+Support helped justify the investment into rotor hardware and the required
+PSTRotator license. Today KST4Contest can automatically control antennas
+during contest operation.
+
+</p>
+
+</article>
+
+<article class="card">
+
+<h3>🗺 Interactive Map</h3>
+
+<p>
+
+The interactive station map required commercial map API usage.
+Community support helped cover those API costs and made the feature possible.
+
+</p>
+
+</article>
+
+</div>
+
+</section>
+
+
+<section class="section">
+
+<div class="section-heading">
+
+<p class="eyebrow">Future goals</p>
+
+<h2>What future support will fund</h2>
+
+</div>
+
+<div class="grid">
+
+<article class="card">
+
+<h3>☁ Map API</h3>
+
+<p>
+
+Keeping the online map service available requires ongoing API usage.
+
+</p>
+
+</article>
+
+<article class="card">
+
+<h3>📡 Tropo Server</h3>
+
+<p>
+
+Future propagation prediction services and server-side calculations
+will require dedicated hosting infrastructure.
+
+</p>
+
+</article>
+
+<article class="card">
+
+<h3>🔌 New Integrations</h3>
+
+<p>
+
+Development of additional interfaces, logging software integrations,
+contest tools and automation features.
+
+</p>
+
+</article>
+
+<article class="card">
+
+<h3>🚀 Faster Development</h3>
+
+<p>
+
+More development time means more contest-oriented features,
+better testing and better documentation.
+
+</p>
+
+</article>
+
+</div>
+
+</section>
+
+
+<section class="section">
+
+<div class="cta-panel">
+
+<p class="eyebrow">Every contribution helps</p>
+
+<h2>Whether it's one coffee or ongoing support.</h2>
+
+<p>
+
+Your support directly improves KST4Contest.
+
+Unlike commercial software, every new feature is driven by real contest
+experience and community feedback.
+
+</p>
+
+<div class="actions">
+
+<a class="button"
+href="https://ko-fi.com/praktimarc"
+target="_blank"
+rel="noopener">
+
+❤️ Support KST4Contest
+
+</a>
+
+</div>
+
+</div>
+
+</section>