feat(radio): improve mode gameplay and leaderboards

Ultraworked with [Sisyphus](https://github.com/code-yeongyu/oh-my-openagent)

Co-authored-by: Sisyphus <clio-agent@sisyphuslabs.ai>

src/components/frontend/radio/RadioArena.tsx

@@ -1,6 +1,6 @@
 "use client";
 
-import { useCallback, useState } from "react";
+import { useCallback, useEffect, useState } from "react";
 import type { RadioStats } from "@/app/(frontend)/radio/actions";
 import { useRealtimePresence } from "@/hooks/useRealtimePresence";
 import { RadioLeaderboard } from "./RadioLeaderboard";
@@ -15,15 +15,29 @@ export function RadioArena({
 }) {
   const [refreshKey, setRefreshKey] = useState(0);
   const [playing, setPlaying] = useState(false);
+  const [mode, setMode] = useState<"sprint" | "watch">("sprint");
+  const [modeHydrated, setModeHydrated] = useState(false);
   const activeOperators = useRealtimePresence("radio", playing, true);
   const onPhaseChange = useCallback((phase: "ready" | "playing" | "over") => {
     setPlaying(phase === "playing");
   }, []);
 
+  useEffect(() => {
+    const savedMode = window.localStorage.getItem("radio-traffic-mode");
+    if (savedMode === "sprint" || savedMode === "watch") setMode(savedMode);
+    setModeHydrated(true);
+  }, []);
+
+  useEffect(() => {
+    if (modeHydrated) window.localStorage.setItem("radio-traffic-mode", mode);
+  }, [mode, modeHydrated]);
+
   return (
     <div className="flex flex-col items-center gap-6">
       <RadioTraffic
         initialStats={initialStats}
+        mode={mode}
+        onModeChangeAction={setMode}
         onGameRecordedAction={() => setRefreshKey((key) => key + 1)}
         onPhaseChangeAction={onPhaseChange}
       />
@@ -47,6 +61,8 @@ export function RadioArena({
       </div>
       <RadioLeaderboard
         refreshKey={refreshKey}
+        mode={mode}
+        modeHydrated={modeHydrated}
         currentUserId={currentUserId}
         activeOperators={activeOperators}
       />

src/components/frontend/radio/RadioLeaderboard.tsx

@@ -1,12 +1,17 @@
 "use client";
 
 import { useEffect, useState } from "react";
-import { Trophy } from "lucide-react";
+import { ArrowDown, ArrowUp, Trophy } from "lucide-react";
-import { Button } from "@/components/ui/button";
 import { cn } from "@/lib/utils";
+import { Tabs, TabsList, TabsTrigger } from "@/components/ui/tabs";
 import type { PresenceParticipant } from "@/hooks/useRealtimePresence";
 
 type LeaderboardTab = "score" | "accuracy" | "messages" | "time";
+type Mode = "sprint" | "watch";
+
+function isLeaderboardTab(value: string): value is LeaderboardTab {
+  return value === "score" || value === "accuracy" || value === "messages" || value === "time";
+}
 
 interface ApiUser {
   id: number;
@@ -22,9 +27,12 @@ interface ApiProfile {
   progression?: {
     minigames?: {
         radioTraffic?: {
-          totalMessages?: number | null;
+          sprintTotalMessages?: number | null;
-          bestScore?: number | null;
+          sprintBestScore?: number | null;
-          bestAccuracy?: number | null;
+          sprintBestAccuracy?: number | null;
+          watchTotalMessages?: number | null;
+          watchBestScore?: number | null;
+          watchBestAccuracy?: number | null;
           bestSprintTimeMs?: number | null;
         } | null;
     } | null;
@@ -42,46 +50,20 @@ interface LeaderboardRow {
   isOutsideTopTen?: boolean;
 }
 
-interface TabConfig {
-  readonly label: string;
-  readonly sort: string;
-  readonly matches: (row: LeaderboardRow) => boolean;
-  readonly empty: string;
-}
-
 interface RadioLeaderboardProps {
   refreshKey?: number;
+  mode: Mode;
+  modeHydrated: boolean;
   currentUserId?: number | string;
   activeOperators?: PresenceParticipant[];
 }
 
-const TAB_ORDER = ["score", "accuracy", "messages", "time"] as const satisfies readonly LeaderboardTab[];
 const TAB_CONFIG = {
-  score: {
+  score: { label: "Top Score", empty: "No scored transmissions yet. Take the first slot!" },
-    label: "Top Score",
+  accuracy: { label: "Top Accuracy", empty: "No accuracy records yet. Relay a perfect transmission!" },
-    sort: "-progression.minigames.radioTraffic.bestScore",
+  messages: { label: "Most Correct", empty: "No correct transmissions yet. Get on frequency!" },
-    matches: (row) => row.bestScore > 0,
+  time: { label: "Fastest Sprint", empty: "No sprint times yet. Complete a 10-message sprint!" },
-    empty: "No scored transmissions yet. Take the first slot!",
+} as const;
-  },
-  accuracy: {
-    label: "Top Accuracy",
-    sort: "-progression.minigames.radioTraffic.bestAccuracy",
-    matches: (row) => row.bestAccuracy > 0,
-    empty: "No accuracy records yet. Relay a perfect transmission!",
-  },
-  messages: {
-    label: "Most Messages",
-    sort: "-progression.minigames.radioTraffic.totalMessages",
-    matches: (row) => row.totalMessages > 0,
-    empty: "No accurate messages yet. Get on frequency!",
-  },
-  time: {
-    label: "Fastest Sprint",
-    sort: "progression.minigames.radioTraffic.bestSprintTimeMs",
-    matches: (row) => row.bestSprintTimeMs > 0,
-    empty: "No sprint times yet. Complete a 10-message sprint!",
-  },
-} satisfies Record<LeaderboardTab, TabConfig>;
 
 function rankClass(index: number) {
   if (index === 0) return "font-bold text-amber-400";
@@ -92,6 +74,8 @@ function rankClass(index: number) {
 
 export function RadioLeaderboard({
   refreshKey = 0,
+  mode,
+  modeHydrated,
   currentUserId,
   activeOperators = [],
 }: RadioLeaderboardProps) {
@@ -99,13 +83,45 @@ export function RadioLeaderboard({
   const [rows, setRows] = useState<LeaderboardRow[] | null>(null);
   const [failed, setFailed] = useState(false);
   const tabConfig = TAB_CONFIG[tab];
+  const tabOrder: readonly LeaderboardTab[] =
+    mode === "sprint"
+      ? ["score", "accuracy", "messages", "time"]
+      : ["score", "accuracy", "messages"];
+  const sortDirection = tab === "time" ? "ascending" : "descending";
+  const SortMarker = ({ column }: { column: LeaderboardTab }) => {
+    if (tab !== column) return null;
+
+    const Icon = sortDirection === "ascending" ? ArrowUp : ArrowDown;
+    return (
+      <Icon
+        aria-hidden="true"
+        className="ml-1 inline-block size-3 text-primary"
+        strokeWidth={2.5}
+      />
+    );
+  };
 
   useEffect(() => {
+    if (mode === "watch" && tab === "time") setTab("score");
+  }, [mode, tab]);
+
+  useEffect(() => {
+    if (!modeHydrated || (mode === "watch" && tab === "time")) return;
     let cancelled = false;
     setFailed(false);
     setRows(null);
 
-    const params = new URLSearchParams({ sort: tabConfig.sort, limit: "100", depth: "1" });
+    const field =
+      tab === "time"
+        ? "bestSprintTimeMs"
+        : mode === "sprint"
+          ? `sprint${tab === "score" ? "BestScore" : tab === "accuracy" ? "BestAccuracy" : "TotalMessages"}`
+          : `watch${tab === "score" ? "BestScore" : tab === "accuracy" ? "BestAccuracy" : "TotalMessages"}`;
+    const params = new URLSearchParams({
+      sort: `${tab === "time" ? "" : "-"}progression.minigames.radioTraffic.${field}`,
+      limit: "100",
+      depth: "1",
+    });
     fetch(`/api/profiles?${params.toString()}`)
       .then((res) => {
         if (!res.ok) throw new Error("leaderboard fetch failed");
@@ -119,14 +135,26 @@ export function RadioLeaderboard({
           return {
             id: doc.id,
             name: user?.displayName || doc.profileTitle || user?.username || `Operator #${doc.id}`,
-            totalMessages: radioTraffic.totalMessages ?? 0,
+            totalMessages:
-            bestScore: radioTraffic.bestScore ?? 0,
+              radioTraffic[mode === "sprint" ? "sprintTotalMessages" : "watchTotalMessages"] ?? 0,
-            bestAccuracy: radioTraffic.bestAccuracy ?? 0,
+            bestScore: radioTraffic[mode === "sprint" ? "sprintBestScore" : "watchBestScore"] ?? 0,
+            bestAccuracy:
+              radioTraffic[mode === "sprint" ? "sprintBestAccuracy" : "watchBestAccuracy"] ?? 0,
             bestSprintTimeMs: radioTraffic.bestSprintTimeMs ?? 0,
             isCurrentUser: user ? String(user.id) === String(currentUserId) : false,
           };
         });
-        const visible = mapped.filter(tabConfig.matches).slice(0, 10);
+        const visible = mapped
+          .filter((row) =>
+            (tab === "score"
+              ? row.bestScore
+              : tab === "accuracy"
+                ? row.bestAccuracy
+                : tab === "messages"
+                  ? row.totalMessages
+                  : row.bestSprintTimeMs) > 0,
+          )
+          .slice(0, 10);
         const current = mapped.find((row) => row.isCurrentUser);
         if (current && !visible.some((row) => row.id === current.id)) {
           visible.push({ ...current, isOutsideTopTen: true });
@@ -140,36 +168,36 @@ export function RadioLeaderboard({
     return () => {
       cancelled = true;
     };
-  }, [currentUserId, refreshKey, tabConfig.matches, tabConfig.sort]);
+  }, [currentUserId, mode, modeHydrated, refreshKey, tab]);
 
   return (
     <div className="w-full max-w-[520px] rounded-xl border border-border bg-card">
       <div className="border-b border-border px-4 py-3">
         <div className="flex items-center gap-2">
           <Trophy className="size-4 text-amber-400" />
-          <h2 className="text-sm font-semibold">Radio Traffic Leaderboard</h2>
+          <h2 className="text-sm font-semibold">
+            Radio Traffic {mode === "sprint" ? "Sprint" : "Watch"} Leaderboard
+          </h2>
           <span className="ml-auto text-xs text-muted-foreground">Top 10</span>
         </div>
-        <div
+        <Tabs
-              className="mt-3 grid grid-cols-4 gap-1 rounded-lg bg-muted p-1"
+          value={tab}
-          role="tablist"
+          onValueChange={(value) => {
-          aria-label="Radio traffic leaderboard"
+            if (isLeaderboardTab(value)) setTab(value);
+          }}
         >
-          {TAB_ORDER.map((value) => (
+          <TabsList
-            <Button
+            id="radio-traffic-leaderboard-tabs"
-              key={value}
+            aria-label="Radio traffic leaderboard"
-              type="button"
+            className={`mt-3 grid w-full ${mode === "sprint" ? "grid-cols-4" : "grid-cols-3"}`}
-              role="tab"
+          >
-              aria-selected={tab === value}
+            {tabOrder.map((value) => (
-              variant={tab === value ? "secondary" : "ghost"}
+              <TabsTrigger key={value} value={value} className="min-w-0 px-2 text-xs">
-              size="sm"
+                {TAB_CONFIG[value].label}
-              className="px-2 text-xs"
+              </TabsTrigger>
-              onClick={() => setTab(value)}
+            ))}
-            >
+          </TabsList>
-              {TAB_CONFIG[value].label}
+        </Tabs>
-            </Button>
-          ))}
-        </div>
       </div>
       <div className="border-b border-border px-4 py-2 text-xs text-muted-foreground" aria-live="polite">
         <span className="font-medium text-emerald-400">
@@ -194,15 +222,53 @@ export function RadioLeaderboard({
         <p className="px-4 py-4 text-sm text-muted-foreground">{tabConfig.empty}</p>
       ) : (
         <div className="overflow-x-auto">
-          <table className="w-full text-sm">
+          <table id="radio-traffic-leaderboard-table" className="w-full text-sm">
             <thead>
               <tr className="text-left text-xs uppercase tracking-wider text-muted-foreground">
                 <th className="px-4 py-2 font-medium">#</th>
                 <th className="px-2 py-2 font-medium">Operator</th>
-                <th className="px-2 py-2 text-right font-medium">Score</th>
+                <th
-                <th className="px-2 py-2 text-right font-medium">Accuracy</th>
+                  aria-sort={tab === "score" ? sortDirection : "none"}
-                <th className="px-2 py-2 text-right font-medium">Time</th>
+                  className={cn(
-                <th className="px-4 py-2 text-right font-medium">Messages</th>
+                    "px-2 py-2 text-right font-medium",
+                    tab === "score" && "text-foreground",
+                  )}
+                >
+                  Score
+                  <SortMarker column="score" />
+                </th>
+                <th
+                  aria-sort={tab === "accuracy" ? sortDirection : "none"}
+                  className={cn(
+                    "px-2 py-2 text-right font-medium",
+                    tab === "accuracy" && "text-foreground",
+                  )}
+                >
+                  Accuracy
+                  <SortMarker column="accuracy" />
+                </th>
+                {mode === "sprint" && (
+                  <th
+                    aria-sort={tab === "time" ? sortDirection : "none"}
+                    className={cn(
+                      "px-2 py-2 text-right font-medium",
+                      tab === "time" && "text-foreground",
+                    )}
+                  >
+                    Time
+                    <SortMarker column="time" />
+                  </th>
+                )}
+                <th
+                  aria-sort={tab === "messages" ? sortDirection : "none"}
+                  className={cn(
+                    "px-4 py-2 text-right font-medium",
+                    tab === "messages" && "text-foreground",
+                  )}
+                >
+                  Correct
+                  <SortMarker column="messages" />
+                </th>
               </tr>
             </thead>
             <tbody className="divide-y divide-border">
@@ -248,9 +314,11 @@ export function RadioLeaderboard({
                   <td className="px-2 py-2 text-right font-semibold tabular-nums">
                     {(row.bestAccuracy * 100).toFixed(2)}%
                   </td>
-                  <td className="px-2 py-2 text-right tabular-nums">
+                  {mode === "sprint" && (
-                    {row.bestSprintTimeMs > 0 ? `${(row.bestSprintTimeMs / 1000).toFixed(1)}s` : "—"}
+                    <td className="px-2 py-2 text-right tabular-nums">
-                  </td>
+                      {row.bestSprintTimeMs > 0 ? `${(row.bestSprintTimeMs / 1000).toFixed(1)}s` : "—"}
+                    </td>
+                  )}
                   <td className="px-4 py-2 text-right tabular-nums text-muted-foreground">
                     {row.totalMessages}
                   </td>

src/components/frontend/radio/RadioTraffic.tsx

@@ -27,12 +27,18 @@ type MessageResult = {
   readonly accuracy: number;
   readonly correct: boolean;
 };
+type ReferenceCharacter = { readonly character: string; readonly matched: boolean };
+type IncorrectSprintSubmission = {
+  readonly target: string;
+  readonly characters: readonly ReferenceCharacter[];
+};
 type Feedback = { readonly correct: boolean; readonly message: string };
 type LastRun = {
   readonly mode: Mode;
   readonly score: number;
   readonly accuracy: number;
   readonly correctMessages: number;
+  readonly incorrectMessages: number;
   readonly relayedMessages: number;
   readonly xpEarned: number;
   readonly best: number;
@@ -44,13 +50,9 @@ const WATCH_DURATION_MS = 60_000;
 const WATCH_MAX_MESSAGES = 30;
 const FAST_TICK_THRESHOLD_MS = 10_000;
 const CRITICAL_TICK_THRESHOLD_MS = 3_000;
-const MODE_STORAGE_KEY = "radio-traffic-mode";
+const UNSUCCESSFUL_SUBMIT_COOLDOWN_MS = 750;
 const TICK_SOUND_STORAGE_KEY = "radio-traffic-tick-sound";
 
-function isMode(value: string | null): value is Mode {
-  return value === "sprint" || value === "watch";
-}
-
 function messageScore(accuracy: number, timeMs: number): number {
   const speed = Math.min(1.5, Math.max(0.25, 1.2 - timeMs / 15_000));
   return Math.round(accuracy * 100 * speed);
@@ -64,6 +66,61 @@ function formatAccuracy(accuracy: number): string {
   return `${Math.round(accuracy * 100)}%`;
 }
 
+export function alignReferenceCharacters(
+  target: string,
+  submitted: string,
+): readonly ReferenceCharacter[] {
+  const targetCharacters = Array.from(target);
+  const submittedCharacters = Array.from(submitted);
+  const lcsLengths = Array.from(
+    { length: targetCharacters.length + 1 },
+    () => new Array<number>(submittedCharacters.length + 1).fill(0),
+  );
+
+  for (let targetIndex = targetCharacters.length - 1; targetIndex >= 0; targetIndex -= 1) {
+    for (
+      let submittedIndex = submittedCharacters.length - 1;
+      submittedIndex >= 0;
+      submittedIndex -= 1
+    ) {
+      const charactersMatch = targetCharacters[targetIndex] === submittedCharacters[submittedIndex];
+      lcsLengths[targetIndex][submittedIndex] =
+        charactersMatch
+          ? lcsLengths[targetIndex + 1][submittedIndex + 1] + 1
+          : Math.max(
+              lcsLengths[targetIndex + 1][submittedIndex],
+              lcsLengths[targetIndex][submittedIndex + 1],
+            );
+    }
+  }
+
+  const matchedTargetCharacters = new Array<boolean>(targetCharacters.length).fill(false);
+  let targetIndex = 0;
+  let submittedIndex = 0;
+  let hasPendingInsertion = false;
+  while (targetIndex < targetCharacters.length && submittedIndex < submittedCharacters.length) {
+    if (targetCharacters[targetIndex] === submittedCharacters[submittedIndex]) {
+      matchedTargetCharacters[targetIndex] = !hasPendingInsertion;
+      hasPendingInsertion = false;
+      targetIndex += 1;
+      submittedIndex += 1;
+    } else if (
+      lcsLengths[targetIndex + 1][submittedIndex] > lcsLengths[targetIndex][submittedIndex + 1]
+    ) {
+      hasPendingInsertion = false;
+      targetIndex += 1;
+    } else {
+      hasPendingInsertion = true;
+      submittedIndex += 1;
+    }
+  }
+
+  return targetCharacters.map((character, index) => ({
+    character,
+    matched: matchedTargetCharacters[index],
+  }));
+}
+
 function roundAccuracy(results: readonly MessageResult[]): number {
   const total = results.reduce((sum, result) => sum + result.correctKeys + result.incorrectKeys, 0);
   return total === 0 ? 0 : results.reduce((sum, result) => sum + result.correctKeys, 0) / total;
@@ -80,10 +137,14 @@ function Metric({ label, value }: { label: string; value: string | number }) {
 
 export function RadioTraffic({
   initialStats: serverStats,
+  mode,
+  onModeChangeAction,
   onGameRecordedAction,
   onPhaseChangeAction,
 }: {
   initialStats: RadioStats;
+  mode: Mode;
+  onModeChangeAction: (mode: Mode) => void;
   onGameRecordedAction: () => void;
   onPhaseChangeAction: (phase: Phase) => void;
 }) {
@@ -104,9 +165,9 @@ export function RadioTraffic({
   const lastCountdownTickRef = useRef("");
   const countdownEndPlayedRef = useRef(false);
   const tickSoundRef = useRef(true);
+  const submitBlockedUntilRef = useRef(0);
+  const incorrectMessagesRef = useRef(0);
   const [phase, setPhase] = useState<Phase>("ready");
-  const [mode, setMode] = useState<Mode>("sprint");
-  const [modeHydrated, setModeHydrated] = useState(false);
   const [tickSoundEnabled, setTickSoundEnabled] = useState(true);
   const [messages, setMessages] = useState<readonly string[]>(() => {
     const initialRound = createRadioRound(null, SPRINT_MESSAGE_COUNT);
@@ -121,6 +182,8 @@ export function RadioTraffic({
   const [stats, setStats] = useState<RadioStats>(serverStats);
   const [lastRun, setLastRun] = useState<LastRun | null>(null);
   const [feedback, setFeedback] = useState<Feedback | null>(null);
+  const [incorrectSprintSubmission, setIncorrectSprintSubmission] =
+    useState<IncorrectSprintSubmission | null>(null);
   const [submitting, setSubmitting] = useState(false);
 
   const setPhaseSafe = useCallback(
@@ -133,20 +196,13 @@ export function RadioTraffic({
   );
 
   useEffect(() => {
-    const savedMode = window.localStorage.getItem(MODE_STORAGE_KEY);
-    if (isMode(savedMode)) setMode(savedMode);
     const savedTickSound = window.localStorage.getItem(TICK_SOUND_STORAGE_KEY);
     if (savedTickSound === "false") {
       tickSoundRef.current = false;
       setTickSoundEnabled(false);
     }
-    setModeHydrated(true);
   }, []);
 
-  useEffect(() => {
-    if (modeHydrated) window.localStorage.setItem(MODE_STORAGE_KEY, mode);
-  }, [mode, modeHydrated]);
-
   const handleTickSoundChange = useCallback((enabled: boolean) => {
     tickSoundRef.current = enabled;
     setTickSoundEnabled(enabled);
@@ -155,8 +211,17 @@ export function RadioTraffic({
 
   useEffect(() => onPhaseChangeAction("ready"), [onPhaseChangeAction]);
 
+  useEffect(() => {
+    setIncorrectSprintSubmission(null);
+  }, [mode]);
+
   const recordResult = useCallback(
-    async (finalResults: readonly MessageResult[], resultMode: Mode, elapsedMs?: number) => {
+    async (
+      finalResults: readonly MessageResult[],
+      resultMode: Mode,
+      elapsedMs: number | undefined,
+      incorrectMessages: number,
+    ) => {
       if (submittingRef.current) return;
       const score = finalResults.reduce((sum, result) => sum + result.score, 0);
       const correctMessages = finalResults.filter((result) => result.correct).length;
@@ -167,9 +232,13 @@ export function RadioTraffic({
           score,
           accuracy,
           correctMessages,
+          incorrectMessages,
           relayedMessages: finalResults.length,
           xpEarned: 0,
-          best: statsRef.current.bestScore,
+          best:
+            resultMode === "sprint"
+              ? statsRef.current.sprintBestScore
+              : statsRef.current.watchBestScore,
           isNewBest: false,
           error: "Your session expired. Result not recorded.",
         });
@@ -182,6 +251,7 @@ export function RadioTraffic({
         score,
         messageCount: finalResults.length,
         correctMessages,
+        incorrectMessages,
         accuracy,
         mode: resultMode,
         timeMs: elapsedMs,
@@ -190,7 +260,8 @@ export function RadioTraffic({
       setSubmitting(false);
 
       if (result.success && result.data) {
-        const previousBest = statsRef.current.bestScore;
+        const previousBest =
+          resultMode === "sprint" ? statsRef.current.sprintBestScore : statsRef.current.watchBestScore;
         statsRef.current = result.data;
         setStats(result.data);
         onGameRecordedAction();
@@ -208,9 +279,11 @@ export function RadioTraffic({
           score,
           accuracy,
           correctMessages,
+          incorrectMessages,
           relayedMessages: finalResults.length,
           xpEarned: result.data.xpEarned,
-          best: result.data.bestScore,
+          best:
+            resultMode === "sprint" ? result.data.sprintBestScore : result.data.watchBestScore,
           isNewBest: score > previousBest,
         });
       } else {
@@ -219,9 +292,13 @@ export function RadioTraffic({
           score,
           accuracy,
           correctMessages,
+          incorrectMessages,
           relayedMessages: finalResults.length,
           xpEarned: 0,
-          best: statsRef.current.bestScore,
+          best:
+            resultMode === "sprint"
+              ? statsRef.current.sprintBestScore
+              : statsRef.current.watchBestScore,
           isNewBest: false,
           error: result.error ?? "Could not record radio traffic.",
         });
@@ -231,7 +308,11 @@ export function RadioTraffic({
   );
 
   const finishRound = useCallback(
-    (finalResults: readonly MessageResult[], resultMode: Mode) => {
+    (
+      finalResults: readonly MessageResult[],
+      resultMode: Mode,
+      incorrectMessages = incorrectMessagesRef.current,
+    ) => {
       if (phaseRef.current !== "playing") return;
       const lastResult = finalResults[finalResults.length - 1];
       if (lastResult) previousRoundLastMessageRef.current = lastResult.target;
@@ -243,15 +324,16 @@ export function RadioTraffic({
           score: 0,
           accuracy: 0,
           correctMessages: 0,
+          incorrectMessages,
           relayedMessages: 0,
           xpEarned: 0,
-          best: statsRef.current.bestScore,
+          best: statsRef.current.watchBestScore,
           isNewBest: false,
         });
         return;
       }
       const elapsedMs = resultMode === "sprint" ? performance.now() - roundStartedAtRef.current : undefined;
-      void recordResult(finalResults, resultMode, elapsedMs);
+      void recordResult(finalResults, resultMode, elapsedMs, incorrectMessages);
     },
     [recordResult, setPhaseSafe],
   );
@@ -322,6 +404,7 @@ export function RadioTraffic({
     setInput("");
     setResults([]);
     keystrokesRef.current = { correct: 0, incorrect: 0 };
+    incorrectMessagesRef.current = 0;
     setElapsedMs(0);
     const isWatch = mode === "watch";
     const nextRemaining = isWatch ? WATCH_DURATION_MS : 0;
@@ -331,6 +414,7 @@ export function RadioTraffic({
     setRemainingMs(nextRemaining);
     setLastRun(null);
     setFeedback(null);
+    setIncorrectSprintSubmission(null);
     messageStartedAtRef.current = now;
     setPhaseSafe("playing");
     window.setTimeout(() => inputRef.current?.focus(), 0);
@@ -360,9 +444,10 @@ export function RadioTraffic({
     (event: FormEvent<HTMLFormElement>) => {
       event.preventDefault();
       if (phaseRef.current !== "playing" || submittingRef.current) return;
+      const now = performance.now();
+      if (now < submitBlockedUntilRef.current) return;
       const target = messages[messageIndex];
       if (!target) return;
-      const now = performance.now();
       const timeMs = Math.max(1, now - messageStartedAtRef.current);
       const { correct: correctKeys, incorrect: incorrectKeys } = keystrokesRef.current;
       const keyTotal = correctKeys + incorrectKeys;
@@ -375,18 +460,34 @@ export function RadioTraffic({
         accuracy,
         correct: input === target,
       };
-    keystrokesRef.current = { correct: 0, incorrect: 0 };
+      if (!result.correct) {
-    lastCountdownTickRef.current = "";
+        incorrectMessagesRef.current += 1;
+        keystrokesRef.current = { correct: 0, incorrect: 0 };
+        lastCountdownTickRef.current = "";
+        if (mode === "sprint") {
+          setIncorrectSprintSubmission({
+            target,
+            characters: alignReferenceCharacters(target, input),
+          });
+        }
+        setInput("");
+        playError();
+        setFeedback({ correct: false, message: "Signal mismatch. Try the transmission again." });
+        submitBlockedUntilRef.current = now + UNSUCCESSFUL_SUBMIT_COOLDOWN_MS;
+        if (mode === "watch" && now >= roundDeadlineRef.current) {
+          finishRound(results, mode, incorrectMessagesRef.current);
+        }
+        return;
+      }
+
+      keystrokesRef.current = { correct: 0, incorrect: 0 };
+      lastCountdownTickRef.current = "";
       const finalResults = [...results, result];
+      setIncorrectSprintSubmission(null);
       setResults(finalResults);
       setInput("");
-      if (result.correct) {
+      playCorrect();
-        playCorrect();
+      setFeedback({ correct: true, message: "Transmission accepted." });
-        setFeedback({ correct: true, message: "Transmission accepted." });
-      } else {
-        playError();
-        setFeedback({ correct: false, message: "Signal mismatch. Next transmission incoming." });
-      }
 
       const watchExpired = mode === "watch" && now >= roundDeadlineRef.current;
       const watchLimitReached = mode === "watch" && finalResults.length >= WATCH_MAX_MESSAGES;
@@ -420,12 +521,17 @@ export function RadioTraffic({
 
   const displayMode = phase === "over" ? (lastRun?.mode ?? mode) : mode;
   const target = messages[messageIndex] ?? "";
+  const sprintReferenceDiff =
+    mode === "sprint" && incorrectSprintSubmission?.target === target
+      ? incorrectSprintSubmission.characters
+      : null;
   const liveKeyTotal = keystrokesRef.current.correct + keystrokesRef.current.incorrect;
   const currentAccuracy = liveKeyTotal > 0 ? keystrokesRef.current.correct / liveKeyTotal : 0;
   const provisionalScore = results.reduce((sum, result) => sum + result.score, 0);
   const displayScore = lastRun?.score ?? provisionalScore;
   const displayAccuracy = lastRun?.accuracy ?? roundAccuracy(results);
-  const displayCorrect = lastRun?.correctMessages ?? results.filter((result) => result.correct).length;
+  const displayCorrect = lastRun?.correctMessages ?? results.length;
+  const displayIncorrect = lastRun?.incorrectMessages ?? incorrectMessagesRef.current;
   const displayRelayed = lastRun?.relayedMessages ?? results.length;
   const progress =
     displayMode === "sprint"
@@ -469,10 +575,10 @@ export function RadioTraffic({
 
         {(phase === "ready" || phase === "over") && (
           <div className="mt-3 grid grid-cols-2 gap-2" role="group" aria-label="Radio traffic mode">
-            <Button type="button" size="sm" variant={mode === "sprint" ? "secondary" : "outline"} disabled={modeSelectorDisabled} onClick={() => setMode("sprint")}>
+           <Button type="button" size="sm" variant={mode === "sprint" ? "secondary" : "outline"} disabled={modeSelectorDisabled} onClick={() => onModeChangeAction("sprint")}>
               Sprint · 10 messages
             </Button>
-            <Button type="button" size="sm" variant={mode === "watch" ? "secondary" : "outline"} disabled={modeSelectorDisabled} onClick={() => setMode("watch")}>
+             <Button type="button" size="sm" variant={mode === "watch" ? "secondary" : "outline"} disabled={modeSelectorDisabled} onClick={() => onModeChangeAction("watch")}>
               Watch · 60 seconds
             </Button>
           </div>
@@ -485,7 +591,30 @@ export function RadioTraffic({
         </div>}
 
         {phase === "playing" && <div className="flex flex-col gap-4 pt-4">
-          <div className="rounded-lg border border-border bg-background p-4"><p className="text-xs uppercase tracking-wider text-muted-foreground">Incoming transmission</p><p className="mt-3 break-words font-mono text-base leading-relaxed text-foreground">{target}</p></div>
+          <div className="rounded-lg border border-border bg-background p-4">
+            <p className="text-xs uppercase tracking-wider text-muted-foreground">Incoming transmission</p>
+            <p
+              className="mt-3 break-words font-mono text-base leading-relaxed text-foreground"
+              aria-describedby={sprintReferenceDiff ? "radio-traffic-diff-description" : undefined}
+            >
+              {sprintReferenceDiff
+                ? sprintReferenceDiff.map(({ character, matched }, index) => (
+                    <span
+                      key={`${index}-${character}`}
+                      className={matched ? "text-emerald-500" : "text-destructive"}
+                    >
+                      {character}
+                    </span>
+                  ))
+                : target}
+            </p>
+            {sprintReferenceDiff && (
+              <span id="radio-traffic-diff-description" className="sr-only" role="status">
+                Reference text is unchanged. Green characters match your last submission; red characters
+                differ. Typed-only characters are not shown.
+              </span>
+            )}
+          </div>
           <form className="flex flex-col gap-2" onSubmit={submitCurrent}>
             <label htmlFor="radio-traffic-input" className="text-sm font-medium">Type exact transmission</label>
             <div className="flex flex-col gap-2 sm:flex-row"><Input ref={inputRef} id="radio-traffic-input" value={input} onKeyDown={handleKeystroke} onChange={(event) => { setInput(event.target.value.toUpperCase()); playKeystroke(); }} onPaste={(event) => { event.preventDefault(); rejectInsertion(); }} onDrop={(event) => { event.preventDefault(); rejectInsertion(); }} onDragOver={(event) => event.preventDefault()} autoCapitalize="characters" autoComplete="off" autoCorrect="off" autoFocus spellCheck={false} aria-describedby="radio-traffic-hint" className="font-mono sm:flex-1" /><Button type="submit" className="sm:min-w-24">Relay</Button></div>
@@ -497,7 +626,7 @@ export function RadioTraffic({
 
         {phase === "over" && <div className="flex flex-col items-center gap-4 py-8 text-center">
           <div className="flex items-center gap-2 text-emerald-400"><Check className="size-5" /><span className="font-bold uppercase tracking-widest">{displayMode === "sprint" ? "Sprint complete" : "Watch ended"}</span></div>
-          <div className="grid w-full grid-cols-2 gap-3 sm:grid-cols-4"><Metric label="Score" value={displayScore} /><Metric label="Accuracy" value={formatAccuracy(displayAccuracy)} /><Metric label="Messages" value={displayMode === "sprint" ? `${displayCorrect}/${SPRINT_MESSAGE_COUNT}` : displayRelayed} /><Metric label="Best" value={lastRun?.best ?? stats.bestScore} /></div>
+           <div className="grid w-full grid-cols-2 gap-3 sm:grid-cols-5"><Metric label="Score" value={displayScore} /><Metric label="Accuracy" value={formatAccuracy(displayAccuracy)} /><Metric label="Correct" value={displayMode === "sprint" ? `${displayCorrect}/${SPRINT_MESSAGE_COUNT}` : displayRelayed} /><Metric label="Incorrect" value={displayIncorrect} /><Metric label="Best" value={lastRun?.best ?? stats.bestScore} /></div>
           {lastRun?.isNewBest && <Badge variant="outline" className="border-amber-400/40 text-amber-300">New best</Badge>}
           {lastRun?.xpEarned ? <span className="text-sm font-semibold text-emerald-400">+{lastRun.xpEarned} XP</span> : null}
           {lastRun?.error && <p className="text-xs text-destructive">{lastRun.error}</p>}
@@ -507,7 +636,7 @@ export function RadioTraffic({
 
         {expired && <div className="absolute inset-0 flex flex-col items-center justify-center gap-3 rounded-xl bg-background/95 p-6 text-center"><span className="text-2xl font-black uppercase tracking-widest text-amber-400">Session Ending Soon</span><span className="max-w-[260px] text-xs text-muted-foreground">Your session is about to end. The app will refresh when it expires.</span><LoginLink className="mt-1"><Button type="button" size="sm">Log in</Button></LoginLink></div>}
       </div>
-      <div className="flex flex-wrap justify-center gap-6 text-sm text-muted-foreground"><div className="flex items-center gap-1.5"><span>Games</span><span className="font-semibold text-foreground">{stats.gamesPlayed}</span></div><div className="flex items-center gap-1.5"><span>Messages</span><span className="font-semibold text-foreground">{stats.totalMessages}</span></div><div className="flex items-center gap-1.5"><span>Best run</span><span className="font-semibold text-foreground">{stats.bestScore}</span></div><div className="flex items-center gap-1.5"><span>XP from traffic</span><span className="font-semibold text-foreground">{stats.radioTrafficXp}</span></div></div>
+       <div className="flex flex-wrap justify-center gap-6 text-sm text-muted-foreground"><div className="flex items-center gap-1.5"><span>Games</span><span className="font-semibold text-foreground">{stats.gamesPlayed}</span></div><div className="flex items-center gap-1.5"><span>Correct messages</span><span className="font-semibold text-foreground">{stats.totalMessages}</span></div><div className="flex items-center gap-1.5"><span>Incorrect messages</span><span className="font-semibold text-foreground">{stats.incorrectMessages}</span></div><div className="flex items-center gap-1.5"><span>Best run</span><span className="font-semibold text-foreground">{stats.bestScore}</span></div><div className="flex items-center gap-1.5"><span>XP from traffic</span><span className="font-semibold text-foreground">{stats.radioTrafficXp}</span></div></div>
     </div>
   );
 }