feat: replace screen state machine with React Router v7 URL routing

- Install react-router-dom
- Add slugify utility with full TDD test suite (7 tests)
- Wrap app in BrowserRouter in main.tsx
- Add optional onNavigate prop to ExamRunner.goTo
- Create ExamRoute component (deep-link restore + back/forward sync)
- Migrate App.tsx: replace screen useState with <Routes>, all setScreen()
  calls replaced with navigate(), add activateExam for deep-link activation,
  use useLocation for verify/reset-password special layouts
- Remove unused AppScreen type from types.ts

frontend/package-lock.json

@@ -11,7 +11,8 @@
         "dompurify": "^3.4.1",
         "katex": "^0.16.45",
         "react": "^19.2.5",
-        "react-dom": "^19.2.5"
+        "react-dom": "^19.2.5",
+        "react-router-dom": "^7.14.2"
       },
       "devDependencies": {
         "@babel/core": "^7.29.0",
@@ -1791,6 +1792,19 @@
       "dev": true,
       "license": "MIT"
     },
+    "node_modules/cookie": {
+      "version": "1.1.1",
+      "resolved": "https://registry.npmjs.org/cookie/-/cookie-1.1.1.tgz",
+      "integrity": "sha512-ei8Aos7ja0weRpFzJnEA9UHJ/7XQmqglbRwnf2ATjcB9Wq874VKH9kfjjirM6UhU2/E5fFYadylyhFldcqSidQ==",
+      "license": "MIT",
+      "engines": {
+        "node": ">=18"
+      },
+      "funding": {
+        "type": "opencollective",
+        "url": "https://opencollective.com/express"
+      }
+    },
     "node_modules/cross-spawn": {
       "version": "7.0.6",
       "resolved": "https://registry.npmjs.org/cross-spawn/-/cross-spawn-7.0.6.tgz",
@@ -3075,6 +3089,44 @@
         "react": "^19.2.5"
       }
     },
+    "node_modules/react-router": {
+      "version": "7.14.2",
+      "resolved": "https://registry.npmjs.org/react-router/-/react-router-7.14.2.tgz",
+      "integrity": "sha512-yCqNne6I8IB6rVCH7XUvlBK7/QKyqypBFGv+8dj4QBFJiiRX+FG7/nkdAvGElyvVZ/HQP5N19wzteuTARXi5Gw==",
+      "license": "MIT",
+      "dependencies": {
+        "cookie": "^1.0.1",
+        "set-cookie-parser": "^2.6.0"
+      },
+      "engines": {
+        "node": ">=20.0.0"
+      },
+      "peerDependencies": {
+        "react": ">=18",
+        "react-dom": ">=18"
+      },
+      "peerDependenciesMeta": {
+        "react-dom": {
+          "optional": true
+        }
+      }
+    },
+    "node_modules/react-router-dom": {
+      "version": "7.14.2",
+      "resolved": "https://registry.npmjs.org/react-router-dom/-/react-router-dom-7.14.2.tgz",
+      "integrity": "sha512-YZcM5ES8jJSM+KrJ9BdvHHqlnGTg5tH3sC5ChFRj4inosKctdyzBDhOyyHdGk597q2OT6NTrCA1OvB/YDwfekQ==",
+      "license": "MIT",
+      "dependencies": {
+        "react-router": "7.14.2"
+      },
+      "engines": {
+        "node": ">=20.0.0"
+      },
+      "peerDependencies": {
+        "react": ">=18",
+        "react-dom": ">=18"
+      }
+    },
     "node_modules/resolve-from": {
       "version": "4.0.0",
       "resolved": "https://registry.npmjs.org/resolve-from/-/resolve-from-4.0.0.tgz",
@@ -3142,6 +3194,12 @@
         "semver": "bin/semver.js"
       }
     },
+    "node_modules/set-cookie-parser": {
+      "version": "2.7.2",
+      "resolved": "https://registry.npmjs.org/set-cookie-parser/-/set-cookie-parser-2.7.2.tgz",
+      "integrity": "sha512-oeM1lpU/UvhTxw+g3cIfxXHyJRc/uidd3yK1P242gzHds0udQBYzs3y8j4gCCW+ZJ7ad0yctld8RYO+bdurlvw==",
+      "license": "MIT"
+    },
     "node_modules/shebang-command": {
       "version": "2.0.0",
       "resolved": "https://registry.npmjs.org/shebang-command/-/shebang-command-2.0.0.tgz",

frontend/package.json

@@ -15,7 +15,8 @@
     "dompurify": "^3.4.1",
     "katex": "^0.16.45",
     "react": "^19.2.5",
-    "react-dom": "^19.2.5"
+    "react-dom": "^19.2.5",
+    "react-router-dom": "^7.14.2"
   },
   "devDependencies": {
     "@babel/core": "^7.29.0",

frontend/src/App.tsx

@@ -1,57 +1,72 @@
-import { useState, useEffect, useCallback } from 'react'
-import type { AppScreen, Exam, ExamState, HistoryEntry, Tweaks } from './types'
-import { gradeQuestion } from './utils/grading'
-import { loadState, saveState, clearState, loadHistory, appendHistory, clearHistory } from './utils/storage'
-import { apiFetch, isAuthenticated } from './utils/api'
-import { AuthProvider, useAuth } from './contexts/AuthContext'
-import Landing from './components/Landing'
-import ExamRunner from './components/ExamRunner'
-import Results from './components/Results'
-import TweaksPanel from './components/TweaksPanel'
-import AuthModal from './components/AuthModal'
-import EmailVerify from './components/EmailVerify'
-import ResetPassword from './components/ResetPassword'
-import AdminDashboard from './components/AdminDashboard'
+import { useState, useEffect, useCallback } from "react";
+import {
+  useNavigate,
+  useLocation,
+  Routes,
+  Route,
+  Navigate,
+} from "react-router-dom";
+import type { Exam, ExamState, HistoryEntry, Tweaks } from "./types";
+import { gradeQuestion } from "./utils/grading";
+import {
+  loadState,
+  saveState,
+  clearState,
+  loadHistory,
+  appendHistory,
+  clearHistory,
+} from "./utils/storage";
+import { apiFetch, isAuthenticated } from "./utils/api";
+import { slugify } from "./utils/slug";
+import { AuthProvider, useAuth } from "./contexts/AuthContext";
+import Landing from "./components/Landing";
+import ExamRoute from "./components/ExamRoute";
+import Results from "./components/Results";
+import TweaksPanel from "./components/TweaksPanel";
+import AuthModal from "./components/AuthModal";
+import EmailVerify from "./components/EmailVerify";
+import ResetPassword from "./components/ResetPassword";
+import AdminDashboard from "./components/AdminDashboard";
 
-const DEFAULT_TWEAKS: Tweaks = { theme: 'light', fontSize: 'medium', feedbackMode: 'auto' }
+const DEFAULT_TWEAKS: Tweaks = {
+  theme: "light",
+  fontSize: "medium",
+  feedbackMode: "auto",
+};
 
 const withNotes = (state: ExamState): ExamState => ({
   ...state,
-  notes: state.notes ?? '',
-})
+  notes: state.notes ?? "",
+});
 
 function AppInner() {
-  const { user, loading: authLoading, logout } = useAuth()
-  const [screen, setScreen] = useState<AppScreen>('landing')
-  const [exam, setExam] = useState<Exam | null>(null)
-  const [examState, setExamState] = useState<ExamState | null>(null)
-  const [history, setHistory] = useState<HistoryEntry[]>(() => loadHistory())
-  const [tweaks, setTweaks] = useState<Tweaks>(DEFAULT_TWEAKS)
-  const [tweaksOpen, setTweaksOpen] = useState(false)
-  const [authModalOpen, setAuthModalOpen] = useState(false)
-  const [userMenuOpen, setUserMenuOpen] = useState(false)
+  const { user, loading: authLoading, logout } = useAuth();
+  const navigate = useNavigate();
+  const { pathname } = useLocation();
+  const [exam, setExam] = useState<Exam | null>(null);
+  const [examState, setExamState] = useState<ExamState | null>(null);
+  const [history, setHistory] = useState<HistoryEntry[]>(() => loadHistory());
+  const [tweaks, setTweaks] = useState<Tweaks>(DEFAULT_TWEAKS);
+  const [tweaksOpen, setTweaksOpen] = useState(false);
+  const [authModalOpen, setAuthModalOpen] = useState(false);
+  const [userMenuOpen, setUserMenuOpen] = useState(false);
 
-  // Check URL for verify/reset-password routes on mount
-  useEffect(() => {
-    const path = globalThis.location.pathname
-    const search = globalThis.location.search
-    if (path === '/verify' || search.includes('token=') && path === '/verify') {
-      setScreen('verify')
-    } else if (path === '/reset-password') {
-      setScreen('reset-password')
-    } else if (path === '/admin') {
-      setScreen('admin')
-    }
-  }, [])
-
-  // Load history from API when authenticated
   useEffect(() => {
     if (!authLoading && user && isAuthenticated()) {
-      apiFetch<{ results: Array<{
-        id: number; title: string; score_points: number; total_points: number;
-        correct_count: number; graded_count: number; passing_score: number;
-        elapsed_ms: number; completed_at: number; exam_id: number | null;
-      }> }>('/api/results')
+      apiFetch<{
+        results: Array<{
+          id: number;
+          title: string;
+          score_points: number;
+          total_points: number;
+          correct_count: number;
+          graded_count: number;
+          passing_score: number;
+          elapsed_ms: number;
+          completed_at: number;
+          exam_id: number | null;
+        }>;
+      }>("/api/results")
         .then((data) => {
           const apiHistory: HistoryEntry[] = data.results.map((r) => ({
             id: String(r.id),
@@ -64,75 +79,111 @@ function AppInner() {
             scorePoints: r.score_points,
             passingScore: r.passing_score,
             exam: { title: r.title, questions: [] } as unknown as Exam,
-            state: { currentIdx: 0, answers: {}, flags: {}, notes: '', startedAt: 0, feedbackMode: 'end' as const } as ExamState,
+            state: {
+              currentIdx: 0,
+              answers: {},
+              flags: {},
+              notes: "",
+              startedAt: 0,
+              feedbackMode: "end" as const,
+            } as ExamState,
             _remoteId: r.id,
-          }))
-          setHistory(apiHistory)
+          }));
+          setHistory(apiHistory);
         })
         .catch(() => {
-          // Fall back to localStorage
-          setHistory(loadHistory())
-        })
+          setHistory(loadHistory());
+        });
     }
-  }, [user, authLoading])
+  }, [user, authLoading]);
 
   useEffect(() => {
-    document.documentElement.dataset['theme'] = tweaks.theme
-    const sizeMap: Record<string, string> = { small: '14px', medium: '15px', large: '17px' }
-    document.body.style.fontSize = sizeMap[tweaks.fontSize] ?? '15px'
-  }, [tweaks])
+    document.documentElement.dataset["theme"] = tweaks.theme;
+    const sizeMap: Record<string, string> = {
+      small: "14px",
+      medium: "15px",
+      large: "17px",
+    };
+    document.body.style.fontSize = sizeMap[tweaks.fontSize] ?? "15px";
+  }, [tweaks]);
 
   useEffect(() => {
-    if (screen === 'exam' && exam && examState) saveState({ exam, state: examState })
-  }, [exam, examState, screen])
+    if (pathname.startsWith("/exam/") && exam && examState)
+      saveState({ exam, state: examState });
+  }, [exam, examState, pathname]);
 
   const updateTweak = <K extends keyof Tweaks>(key: K, value: Tweaks[K]) =>
-    setTweaks((t) => ({ ...t, [key]: value }))
+    setTweaks((t) => ({ ...t, [key]: value }));
 
-  const setExamStateStrict: React.Dispatch<React.SetStateAction<ExamState>> = (nextState) => {
+  const setExamStateStrict: React.Dispatch<React.SetStateAction<ExamState>> = (
+    nextState,
+  ) => {
     setExamState((prev) => {
-      if (!prev) return prev
-      return typeof nextState === 'function'
+      if (!prev) return prev;
+      return typeof nextState === "function"
         ? (nextState as (prevState: ExamState) => ExamState)(prev)
-        : nextState
-    })
-  }
+        : nextState;
+    });
+  };
+
+  const activateExam = (data: Exam, state: ExamState) => {
+    setExam(data);
+    setExamState(withNotes(state));
+  };
 
   const loadExam = (data: Exam) => {
-    const fm = tweaks.feedbackMode === 'auto' ? (data.feedbackMode ?? 'end') : tweaks.feedbackMode
-    setExam(data)
-    setExamState({ currentIdx: 0, answers: {}, flags: {}, notes: '', revealed: {}, startedAt: Date.now(), feedbackMode: fm })
-    setScreen('exam')
-  }
+    const fm =
+      tweaks.feedbackMode === "auto"
+        ? (data.feedbackMode ?? "end")
+        : tweaks.feedbackMode;
+    setExam(data);
+    setExamState({
+      currentIdx: 0,
+      answers: {},
+      flags: {},
+      notes: "",
+      revealed: {},
+      startedAt: Date.now(),
+      feedbackMode: fm,
+    });
+    navigate(`/exam/${slugify(data.title)}/q1`);
+  };
 
   const resume = () => {
-    const saved = loadState()
-    if (saved?.exam && saved?.state) { setExam(saved.exam); setExamState(withNotes(saved.state)); setScreen('exam') }
-  }
+    const saved = loadState();
+    if (saved?.exam && saved?.state) {
+      setExam(saved.exam);
+      setExamState(withNotes(saved.state));
+      navigate(
+        `/exam/${slugify(saved.exam.title)}/q${saved.state.currentIdx + 1}`,
+      );
+    }
+  };
 
   const submit = useCallback(() => {
-    if (!exam || !examState) return
-    const completedAt = Date.now()
-    const elapsedMs = completedAt - examState.startedAt
-    const graded = exam.questions.map((q) => gradeQuestion(q, examState.answers[q.id]))
+    if (!exam || !examState) return;
+    const completedAt = Date.now();
+    const elapsedMs = completedAt - examState.startedAt;
+    const graded = exam.questions.map((q) =>
+      gradeQuestion(q, examState.answers[q.id]),
+    );
     const entry: HistoryEntry = {
       id: `${Date.now()}-${Math.random().toString(36).slice(2, 7)}`,
       title: exam.title,
       completedAt,
       elapsedMs,
-      gradedCount: graded.filter((r) => r.status !== 'ungraded').length,
+      gradedCount: graded.filter((r) => r.status !== "ungraded").length,
       correctCount: graded.filter((r) => r.correct).length,
       totalPoints: exam.questions.reduce((a, q) => a + (q.points ?? 1), 0),
       scorePoints: graded.reduce((a, r) => a + r.points, 0),
       passingScore: exam.passingScore ?? 60,
       exam,
       state: { ...examState, completedAt },
-    }
+    };
 
-    // Save to API if authenticated
     if (user && isAuthenticated()) {
-      void apiFetch('/api/results', {
-        method: 'POST',
+      void apiFetch("/api/results", {
+        method: "POST",
         body: JSON.stringify({
           title: entry.title,
           scorePoints: entry.scorePoints,
@@ -146,59 +197,73 @@ function AppInner() {
           exam: entry.exam,
         }),
       }).catch(() => {
-        // Fallback: save locally
-        appendHistory(entry)
-      })
+        appendHistory(entry);
+      });
     } else {
-      appendHistory(entry)
+      appendHistory(entry);
     }
 
-    // Always update local state for immediate display
-    setHistory((prev) => [entry, ...prev])
-    clearState()
-    setExamState((s) => s ? { ...s, completedAt } : s)
-    setScreen('results')
-  }, [exam, examState, user])
+    setHistory((prev) => [entry, ...prev]);
+    clearState();
+    setExamState((s) => (s ? { ...s, completedAt } : s));
+    navigate("/results");
+  }, [exam, examState, user, navigate]);
 
-  const exit = () => { setScreen('landing'); setExam(null); setExamState(null) }
-  const restart = () => { if (exam) loadExam(exam) }
+  const exit = () => {
+    setExam(null);
+    setExamState(null);
+    navigate("/");
+  };
+
+  const restart = () => {
+    if (exam) loadExam(exam);
+  };
 
   const reviewAttempt = (entry: HistoryEntry) => {
-    // If this is a remote result, fetch full data
-    const remoteId = (entry as HistoryEntry & { _remoteId?: number })._remoteId
+    const remoteId = (entry as HistoryEntry & { _remoteId?: number })._remoteId;
     if (remoteId && user && isAuthenticated()) {
       void apiFetch<{
-        exam: Exam; state: ExamState; title: string; scorePoints: number; totalPoints: number;
-        correctCount: number; gradedCount: number; passingScore: number; elapsedMs: number; completedAt: number;
+        exam: Exam;
+        state: ExamState;
+        title: string;
+        scorePoints: number;
+        totalPoints: number;
+        correctCount: number;
+        gradedCount: number;
+        passingScore: number;
+        elapsedMs: number;
+        completedAt: number;
       }>(`/api/results/${remoteId}`)
         .then((data) => {
-          setExam(data.exam)
-          setExamState(withNotes(data.state))
-          setScreen('review')
+          setExam(data.exam);
+          setExamState(withNotes(data.state));
+          navigate(`/review/${slugify(entry.title)}`);
         })
         .catch(() => {
-          // Fallback to local data
-          setExam(entry.exam); setExamState(withNotes(entry.state)); setScreen('review')
-        })
+          setExam(entry.exam);
+          setExamState(withNotes(entry.state));
+          navigate(`/review/${slugify(entry.title)}`);
+        });
     } else {
-      setExam(entry.exam); setExamState(withNotes(entry.state)); setScreen('review')
+      setExam(entry.exam);
+      setExamState(withNotes(entry.state));
+      navigate(`/review/${slugify(entry.title)}`);
     }
-  }
+  };
 
   const clearAllHistory = () => {
-    if (confirm('Clear all past attempts?')) {
-      clearHistory()
-      setHistory([])
+    if (confirm("Clear all past attempts?")) {
+      clearHistory();
+      setHistory([]);
     }
-  }
+  };
 
   const handleAuthFlowDone = () => {
-    globalThis.history.replaceState({}, '', '/')
-    setScreen('landing')
-    setAuthModalOpen(true)
-  }
+    navigate("/");
+    setAuthModalOpen(true);
+  };
 
-  if (screen === 'verify') {
+  if (pathname === "/verify") {
     return (
       <div className="shell">
         <header className="topbar">
@@ -209,10 +274,10 @@ function AppInner() {
         </header>
         <EmailVerify onDone={handleAuthFlowDone} />
       </div>
-    )
+    );
   }
 
-  if (screen === 'reset-password') {
+  if (pathname === "/reset-password") {
     return (
       <div className="shell">
         <header className="topbar">
@@ -223,7 +288,7 @@ function AppInner() {
         </header>
         <ResetPassword onDone={handleAuthFlowDone} />
       </div>
-    )
+    );
   }
 
   return (
@@ -235,24 +300,47 @@ function AppInner() {
             className="brand-name"
             onClick={exit}
             aria-label="Home"
-            style={{ background: 'none', border: 'none', padding: 0, margin: 0, cursor: 'pointer', font: 'inherit', color: 'inherit' }}
+            style={{
+              background: "none",
+              border: "none",
+              padding: 0,
+              margin: 0,
+              cursor: "pointer",
+              font: "inherit",
+              color: "inherit",
+            }}
           >
             BrainWave
           </button>
-          <span className="faint mono" style={{ fontSize: 11, marginLeft: 4 }}>/ practice</span>
+          <span className="faint mono" style={{ fontSize: 11, marginLeft: 4 }}>
+            / practice
+          </span>
         </div>
         <div className="topbar-meta">
-          {screen === 'exam' && exam && (
+          {pathname.startsWith("/exam/") && exam && (
             <>
-              <span className="mono" style={{ fontSize: 12 }}>{exam.title}</span>
-              <button className="btn btn-ghost btn-sm" onClick={exit}>Exit</button>
+              <span className="mono" style={{ fontSize: 12 }}>
+                {exam.title}
+              </span>
+              <button className="btn btn-ghost btn-sm" onClick={exit}>
+                Exit
+              </button>
             </>
           )}
-          <button className="btn btn-ghost btn-sm" onClick={() => setTweaksOpen((o) => !o)} style={{ marginLeft: 8 }} aria-label="Tweaks">⚙</button>
+          <button
+            className="btn btn-ghost btn-sm"
+            onClick={() => setTweaksOpen((o) => !o)}
+            style={{ marginLeft: 8 }}
+            aria-label="Tweaks"
+          >
+            ⚙
+          </button>
 
-          {/* Auth buttons */}
           {!authLoading && !user && (
-            <button className="btn btn-primary btn-sm" onClick={() => setAuthModalOpen(true)}>
+            <button
+              className="btn btn-primary btn-sm"
+              onClick={() => setAuthModalOpen(true)}
+            >
               Sign In
             </button>
           )}
@@ -266,48 +354,125 @@ function AppInner() {
                 {user.displayName.charAt(0).toUpperCase()}
               </button>
               {userMenuOpen && (
-                  <div className="user-menu">
-                    <div className="user-menu-header">
-                      <div className="user-menu-name">{user.displayName}</div>
-                      <div className="user-menu-email">{user.email}</div>
-                    </div>
-                    <div className="user-menu-divider" />
-                    {user.role === 'admin' && (
-                      <button className="user-menu-item" onClick={() => { setUserMenuOpen(false); setScreen('admin'); globalThis.history.pushState({}, '', '/admin') }}>
-                        Admin Dashboard
-                      </button>
-                    )}
-                    <button className="user-menu-item" onClick={() => { setUserMenuOpen(false); logout() }}>
-                      Sign Out
-                    </button>
+                <div className="user-menu">
+                  <div className="user-menu-header">
+                    <div className="user-menu-name">{user.displayName}</div>
+                    <div className="user-menu-email">{user.email}</div>
                   </div>
+                  <div className="user-menu-divider" />
+                  {user.role === "admin" && (
+                    <button
+                      className="user-menu-item"
+                      onClick={() => {
+                        setUserMenuOpen(false);
+                        navigate("/admin");
+                      }}
+                    >
+                      Admin Dashboard
+                    </button>
+                  )}
+                  <button
+                    className="user-menu-item"
+                    onClick={() => {
+                      setUserMenuOpen(false);
+                      logout();
+                    }}
+                  >
+                    Sign Out
+                  </button>
+                </div>
               )}
             </div>
           )}
         </div>
       </header>
 
-      {screen === 'landing' && (
-        <Landing onLoadExam={loadExam} history={history} onResume={resume} onClearHistory={clearAllHistory} onReviewAttempt={reviewAttempt} />
+      <Routes>
+        <Route
+          path="/"
+          element={
+            <Landing
+              onLoadExam={loadExam}
+              history={history}
+              onResume={resume}
+              onClearHistory={clearAllHistory}
+              onReviewAttempt={reviewAttempt}
+            />
+          }
+        />
+        <Route
+          path="/exam/:slug/q:n"
+          element={
+            <ExamRoute
+              exam={exam}
+              examState={examState}
+              onActivate={activateExam}
+              setExamState={setExamStateStrict}
+              onSubmit={submit}
+              onExit={exit}
+            />
+          }
+        />
+        <Route
+          path="/results"
+          element={
+            exam && examState ? (
+              <Results
+                exam={exam}
+                state={examState}
+                onRestart={restart}
+                onExit={exit}
+                reviewOnly={false}
+              />
+            ) : (
+              <Navigate to="/" replace />
+            )
+          }
+        />
+        <Route
+          path="/review/:slug"
+          element={
+            exam && examState ? (
+              <Results
+                exam={exam}
+                state={examState}
+                onRestart={restart}
+                onExit={exit}
+                reviewOnly={true}
+              />
+            ) : (
+              <Navigate to="/" replace />
+            )
+          }
+        />
+        <Route
+          path="/admin"
+          element={
+            user?.role === "admin" ? (
+              <AdminDashboard onExit={exit} />
+            ) : (
+              <Navigate to="/" replace />
+            )
+          }
+        />
+        <Route path="*" element={<Navigate to="/" replace />} />
+      </Routes>
+
+      {tweaksOpen && (
+        <TweaksPanel
+          tweaks={tweaks}
+          update={updateTweak}
+          onClose={() => setTweaksOpen(false)}
+        />
       )}
-      {screen === 'admin' && user?.role === 'admin' && (
-        <AdminDashboard onExit={exit} />
-      )}
-      {screen === 'exam' && exam && examState && (
-        <ExamRunner exam={exam} state={examState} setState={setExamStateStrict} onSubmit={submit} onExit={exit} />
-      )}
-      {(screen === 'results' || screen === 'review') && exam && examState && (
-        <Results exam={exam} state={examState} onRestart={restart} onExit={exit} reviewOnly={screen === 'review'} />
-      )}
-      {tweaksOpen && <TweaksPanel tweaks={tweaks} update={updateTweak} onClose={() => setTweaksOpen(false)} />}
       {authModalOpen && (
         <AuthModal
           onClose={() => setAuthModalOpen(false)}
-          onForgotPassword={() => setScreen('reset-password')}
+          onForgotPassword={() => navigate("/reset-password")}
         />
       )}
     </div>
-  )
+  );
 }
 
 export default function App() {
@@ -315,5 +480,5 @@ export default function App() {
     <AuthProvider>
       <AppInner />
     </AuthProvider>
-  )
+  );
 }

frontend/src/components/ExamRoute.tsx

@@ -0,0 +1,55 @@
+import { useParams, useNavigate } from 'react-router-dom'
+import { useEffect } from 'react'
+import type { Dispatch, SetStateAction } from 'react'
+import ExamRunner from './ExamRunner'
+import { loadState } from '../utils/storage'
+import { slugify } from '../utils/slug'
+import type { Exam, ExamState } from '../types'
+
+interface Props {
+  exam: Exam | null
+  examState: ExamState | null
+  onActivate: (exam: Exam, state: ExamState) => void
+  setExamState: Dispatch<SetStateAction<ExamState>>
+  onSubmit: () => void
+  onExit: () => void
+}
+
+export default function ExamRoute({ exam, examState, onActivate, setExamState, onSubmit, onExit }: Readonly<Props>) {
+  const { slug, n } = useParams<{ slug: string; n: string }>()
+  const navigate = useNavigate()
+
+  const questionIdx = Math.max(0, (Number(n) || 1) - 1)
+
+  // Deep link: restore from localStorage if no exam is active on mount
+  useEffect(() => {
+    if (!exam) {
+      const saved = loadState()
+      if (saved?.exam && slugify(saved.exam.title) === slug) {
+        onActivate(saved.exam, { ...saved.state, currentIdx: questionIdx })
+      } else {
+        navigate('/', { replace: true })
+      }
+    }
+    // Intentionally runs only on mount — dep changes after mount are handled by the sync effect below
+    // eslint-disable-next-line react-hooks/exhaustive-deps
+  }, [])
+
+  // Sync :n URL param to currentIdx (handles browser back/forward navigation)
+  useEffect(() => {
+    setExamState((s) => s ? { ...s, currentIdx: questionIdx } : s)
+  }, [questionIdx, setExamState])
+
+  if (!exam || !examState) return null
+
+  return (
+    <ExamRunner
+      exam={exam}
+      state={examState}
+      setState={setExamState}
+      onNavigate={(i) => navigate(`/exam/${slug}/q${i + 1}`)}
+      onSubmit={onSubmit}
+      onExit={onExit}
+    />
+  )
+}

frontend/src/components/ExamRunner.tsx

@@ -1,107 +1,143 @@
-import { useState, useEffect, useCallback } from 'react'
-import type { Exam, ExamState, Question } from '../types'
-import { gradeQuestion } from '../utils/grading'
-import { formatTime } from '../utils/formatting'
-import Tex from './Tex'
-import QuestionMedia from './QuestionMedia'
-import QuestionRenderer from './questions/QuestionRenderer'
+import { useState, useEffect, useCallback } from "react";
+import type { Exam, ExamState, Question } from "../types";
+import { gradeQuestion } from "../utils/grading";
+import { formatTime } from "../utils/formatting";
+import Tex from "./Tex";
+import QuestionMedia from "./QuestionMedia";
+import QuestionRenderer from "./questions/QuestionRenderer";
 
 interface Props {
-  exam: Exam
-  state: ExamState
-  setState: React.Dispatch<React.SetStateAction<ExamState>>
-  onSubmit: () => void
-  onExit: () => void
+  exam: Exam;
+  state: ExamState;
+  setState: React.Dispatch<React.SetStateAction<ExamState>>;
+  onSubmit: () => void;
+  onExit: () => void;
+  onNavigate?: (i: number) => void;
 }
 
-export default function ExamRunner({ exam, state, setState, onSubmit, onExit }: Readonly<Props>) {
-  const { currentIdx, answers, flags, startedAt, feedbackMode } = state
-  const q = exam.questions[currentIdx]
-  const total = exam.questions.length
-  const notes = state.notes ?? ''
+export default function ExamRunner({
+  exam,
+  state,
+  setState,
+  onSubmit,
+  onExit,
+  onNavigate,
+}: Readonly<Props>) {
+  const { currentIdx, answers, flags, startedAt, feedbackMode } = state;
+  const q = exam.questions[currentIdx];
+  const total = exam.questions.length;
+  const notes = state.notes ?? "";
 
-  const [revealed, setRevealed] = useState(() => !!state.revealed?.[q.id])
-  useEffect(() => { setRevealed(!!state.revealed?.[q.id]) }, [currentIdx, q.id, state.revealed])
+  const [revealed, setRevealed] = useState(() => !!state.revealed?.[q.id]);
+  useEffect(() => {
+    setRevealed(!!state.revealed?.[q.id]);
+  }, [currentIdx, q.id, state.revealed]);
 
   const setAnswer = (val: unknown) =>
-    setState((s) => ({ ...s, answers: { ...s.answers, [q.id]: val } }))
+    setState((s) => ({ ...s, answers: { ...s.answers, [q.id]: val } }));
 
-  const goTo = useCallback((i: number) =>
-    setState((s) => ({ ...s, currentIdx: Math.max(0, Math.min(total - 1, i)) })), [total])
+  const goTo = useCallback(
+    (i: number) => {
+      const next = Math.max(0, Math.min(total - 1, i));
+      setState((s) => ({ ...s, currentIdx: next }));
+      onNavigate?.(next);
+    },
+    [total, onNavigate],
+  );
 
-  const toggleFlag = useCallback(() =>
-    setState((s) => ({ ...s, flags: { ...s.flags, [q.id]: !s.flags[q.id] } })), [q.id])
+  const toggleFlag = useCallback(
+    () =>
+      setState((s) => ({
+        ...s,
+        flags: { ...s.flags, [q.id]: !s.flags[q.id] },
+      })),
+    [q.id],
+  );
 
   const updateNotes = (value: string) =>
-    setState((s) => ({ ...s, notes: value.slice(0, 1000) }))
+    setState((s) => ({ ...s, notes: value.slice(0, 1000) }));
 
   const checkAnswer = () => {
     setState((s) => ({
       ...s,
       revealed: s.revealed ? { ...s.revealed, [q.id]: true } : { [q.id]: true },
-    }))
-    setRevealed(true)
-  }
+    }));
+    setRevealed(true);
+  };
 
-  const [now, setNow] = useState(Date.now())
+  const [now, setNow] = useState(Date.now());
   useEffect(() => {
-    const t = setInterval(() => setNow(Date.now()), 1000)
-    return () => clearInterval(t)
-  }, [])
+    const t = setInterval(() => setNow(Date.now()), 1000);
+    return () => clearInterval(t);
+  }, []);
 
-  const elapsedMs = now - startedAt
-  const remainingMs = exam.timeLimitMinutes ? exam.timeLimitMinutes * 60_000 - elapsedMs : null
-  const timeUrgent = remainingMs != null && remainingMs < 60_000
+  const elapsedMs = now - startedAt;
+  const remainingMs = exam.timeLimitMinutes
+    ? exam.timeLimitMinutes * 60_000 - elapsedMs
+    : null;
+  const timeUrgent = remainingMs != null && remainingMs < 60_000;
 
   useEffect(() => {
-    if (remainingMs != null && remainingMs <= 0) onSubmit()
-  }, [remainingMs, onSubmit])
+    if (remainingMs != null && remainingMs <= 0) onSubmit();
+  }, [remainingMs, onSubmit]);
 
   useEffect(() => {
     const handler = (e: KeyboardEvent) => {
-      const tag = (e.target as HTMLElement).tagName
-      if (tag === 'INPUT' || tag === 'TEXTAREA') return
-      if (e.key === 'ArrowRight' || e.key === 'j') goTo(currentIdx + 1)
-      if (e.key === 'ArrowLeft' || e.key === 'k') goTo(currentIdx - 1)
-      if (e.key === 'f') toggleFlag()
-      if (/^[1-9]$/.test(e.key) && q.type === 'multiple-choice' && q.choices) {
-        const ci = Number.parseInt(e.key, 10) - 1
-        const choices = q.choices
-        if (choices[ci]) setState((s) => ({ ...s, answers: { ...s.answers, [q.id]: choices[ci].id } }))
+      const tag = (e.target as HTMLElement).tagName;
+      if (tag === "INPUT" || tag === "TEXTAREA") return;
+      if (e.key === "ArrowRight" || e.key === "j") goTo(currentIdx + 1);
+      if (e.key === "ArrowLeft" || e.key === "k") goTo(currentIdx - 1);
+      if (e.key === "f") toggleFlag();
+      if (/^[1-9]$/.test(e.key) && q.type === "multiple-choice" && q.choices) {
+        const ci = Number.parseInt(e.key, 10) - 1;
+        const choices = q.choices;
+        if (choices[ci])
+          setState((s) => ({
+            ...s,
+            answers: { ...s.answers, [q.id]: choices[ci].id },
+          }));
       }
-    }
-    globalThis.addEventListener('keydown', handler)
-    return () => globalThis.removeEventListener('keydown', handler)
-  }, [currentIdx, q, goTo, toggleFlag, setState])
+    };
+    globalThis.addEventListener("keydown", handler);
+    return () => globalThis.removeEventListener("keydown", handler);
+  }, [currentIdx, q, goTo, toggleFlag, setState]);
 
-  const graded = feedbackMode === 'immediate' && revealed
-  const answered = answers[q.id] != null && (!Array.isArray(answers[q.id]) || (answers[q.id] as unknown[]).length > 0)
-  const result = graded ? gradeQuestion(q, answers[q.id]) : null
+  const graded = feedbackMode === "immediate" && revealed;
+  const answered =
+    answers[q.id] != null &&
+    (!Array.isArray(answers[q.id]) || (answers[q.id] as unknown[]).length > 0);
+  const result = graded ? gradeQuestion(q, answers[q.id]) : null;
 
   const navStatus = (qq: Question): string => {
-    if (feedbackMode === 'immediate' && state.revealed?.[qq.id]) {
-      const r = gradeQuestion(qq, answers[qq.id])
-      if (r.status === 'correct') return 'correct'
-      if (r.status === 'wrong') return 'wrong'
+    if (feedbackMode === "immediate" && state.revealed?.[qq.id]) {
+      const r = gradeQuestion(qq, answers[qq.id]);
+      if (r.status === "correct") return "correct";
+      if (r.status === "wrong") return "wrong";
       // fall through to answered/flagged for ungraded/unanswered revealed states (e.g. essay)
     }
-    if (flags[qq.id]) return 'flagged'
-    const a = answers[qq.id]
-    if (a != null && (!Array.isArray(a) || (a as unknown[]).length > 0)) return 'answered'
-    return ''
-  }
+    if (flags[qq.id]) return "flagged";
+    const a = answers[qq.id];
+    if (a != null && (!Array.isArray(a) || (a as unknown[]).length > 0))
+      return "answered";
+    return "";
+  };
 
   const answeredCount = exam.questions.filter((qq) => {
-    const st = navStatus(qq)
-    return st === 'answered' || st === 'correct' || st === 'wrong'
-  }).length
+    const st = navStatus(qq);
+    return st === "answered" || st === "correct" || st === "wrong";
+  }).length;
 
-  const totalPossible = exam.questions.reduce((acc, qq) => acc + (qq.points ?? 1), 0)
-  let answerText = ''
-  if (!Array.isArray(q.answer) && typeof q.answer === 'string') {
-    answerText = q.choices?.find((c) => c.id === q.answer)?.text ?? q.answer
+  const totalPossible = exam.questions.reduce(
+    (acc, qq) => acc + (qq.points ?? 1),
+    0,
+  );
+  let answerText = "";
+  if (!Array.isArray(q.answer) && typeof q.answer === "string") {
+    answerText = q.choices?.find((c) => c.id === q.answer)?.text ?? q.answer;
   } else if (Array.isArray(q.answer)) {
-    answerText = q.answer.map((id) => q.choices?.find((c) => c.id === id)?.text ?? id).join(', ')
+    answerText = q.answer
+      .map((id) => q.choices?.find((c) => c.id === id)?.text ?? id)
+      .join(", ");
   }
 
   return (
@@ -113,78 +149,155 @@ export default function ExamRunner({ exam, state, setState, onSubmit, onExit }:
         <div className="sidebar-section-label">Questions</div>
         <div className="nav-list">
           {exam.questions.map((qq, i) => {
-            const st = navStatus(qq)
+            const st = navStatus(qq);
             return (
-              <button key={qq.id} className={`nav-item${i === currentIdx ? ' active' : ''}`} onClick={() => goTo(i)}>
-                <span className="nav-item-num">{String(i + 1).padStart(2, '0')}</span>
-                <span className="nav-item-title">
-                  {qq.category ? `${qq.category} · ` : ''}{qq.type.replace('-', ' ')}
+              <button
+                key={qq.id}
+                className={`nav-item${i === currentIdx ? " active" : ""}`}
+                onClick={() => goTo(i)}
+              >
+                <span className="nav-item-num">
+                  {String(i + 1).padStart(2, "0")}
                 </span>
-                <span className={`nav-dot${st ? ' ' + st : ''}`} />
+                <span className="nav-item-title">
+                  {qq.category ? `${qq.category} · ` : ""}
+                  {qq.type.replace("-", " ")}
+                </span>
+                <span className={`nav-dot${st ? " " + st : ""}`} />
               </button>
-            )
+            );
           })}
         </div>
 
         <div className="sidebar-section-label">Progress</div>
-        <div className="mono" style={{ fontSize: 13, color: 'var(--ink-2)' }}>
+        <div className="mono" style={{ fontSize: 13, color: "var(--ink-2)" }}>
           {answeredCount} of {total} answered
         </div>
         <div className="progress-bar">
           <div style={{ width: `${(answeredCount / total) * 100}%` }} />
         </div>
 
-        <div style={{ marginTop: 32, display: 'flex', flexDirection: 'column', gap: 8 }}>
-          <button className="btn btn-primary" onClick={onSubmit}>Submit exam</button>
-          <button className="btn btn-ghost btn-sm" onClick={onExit}>Exit to home</button>
+        <div
+          style={{
+            marginTop: 32,
+            display: "flex",
+            flexDirection: "column",
+            gap: 8,
+          }}
+        >
+          <button className="btn btn-primary" onClick={onSubmit}>
+            Submit exam
+          </button>
+          <button className="btn btn-ghost btn-sm" onClick={onExit}>
+            Exit to home
+          </button>
         </div>
       </aside>
 
       <main className="main">
         <header className="question-header">
-          <span className="q-index">Question {String(currentIdx + 1).padStart(2, '0')} / {String(total).padStart(2, '0')}</span>
+          <span className="q-index">
+            Question {String(currentIdx + 1).padStart(2, "0")} /{" "}
+            {String(total).padStart(2, "0")}
+          </span>
           {q.category && <span className="q-category">{q.category}</span>}
-          <span className="q-points">{q.points ?? 1} {(q.points ?? 1) === 1 ? 'pt' : 'pts'}</span>
+          <span className="q-points">
+            {q.points ?? 1} {(q.points ?? 1) === 1 ? "pt" : "pts"}
+          </span>
         </header>
 
-        <Tex tag="div" className="q-prompt">{q.prompt}</Tex>
+        <Tex tag="div" className="q-prompt">
+          {q.prompt}
+        </Tex>
         <QuestionMedia q={q} />
-        <QuestionRenderer key={q.id} q={q} value={answers[q.id]} onChange={setAnswer} locked={graded && q.type !== 'essay'} graded={graded} />
+        <QuestionRenderer
+          key={q.id}
+          q={q}
+          value={answers[q.id]}
+          onChange={setAnswer}
+          locked={graded && q.type !== "essay"}
+          graded={graded}
+        />
 
-        {graded && result && q.type !== 'essay' && (
-          <div className={`feedback ${result.correct ? 'correct' : 'wrong'}`}>
-            <div className="feedback-label">{result.correct ? 'Correct' : 'Not quite'}</div>
+        {graded && result && q.type !== "essay" && (
+          <div className={`feedback ${result.correct ? "correct" : "wrong"}`}>
+            <div className="feedback-label">
+              {result.correct ? "Correct" : "Not quite"}
+            </div>
             <div className="feedback-body">
-              {!result.correct && q.answer && q.type !== 'match' && q.type !== 'order' && (
+              {!result.correct &&
+                q.answer &&
+                q.type !== "match" &&
+                q.type !== "order" && (
+                  <p>
+                    <strong>Answer:</strong> <Tex>{answerText}</Tex>
+                  </p>
+                )}
+              {q.explanation && (
                 <p>
-                  <strong>Answer:</strong>{' '}
-                  <Tex>{answerText}</Tex>
+                  <Tex>{q.explanation}</Tex>
                 </p>
               )}
-              {q.explanation && <p><Tex>{q.explanation}</Tex></p>}
             </div>
           </div>
         )}
 
         <footer className="exam-footer">
-          <button className="btn" onClick={() => goTo(currentIdx - 1)} disabled={currentIdx === 0}>← Previous</button>
+          <button
+            className="btn"
+            onClick={() => goTo(currentIdx - 1)}
+            disabled={currentIdx === 0}
+          >
+            ← Previous
+          </button>
           <button className="btn btn-ghost" onClick={toggleFlag}>
-            {flags[q.id] ? '⚑ Flagged' : '⚐ Flag for review'}
+            {flags[q.id] ? "⚑ Flagged" : "⚐ Flag for review"}
           </button>
           <span className="spacer" />
-          {feedbackMode === 'immediate' && !revealed && q.type !== 'essay' && answered && (
-            <button className="btn btn-primary" onClick={checkAnswer}>Check answer</button>
+          {feedbackMode === "immediate" &&
+            !revealed &&
+            q.type !== "essay" &&
+            answered && (
+              <button className="btn btn-primary" onClick={checkAnswer}>
+                Check answer
+              </button>
+            )}
+          {currentIdx < total - 1 ? (
+            <button
+              className="btn btn-primary"
+              onClick={() => goTo(currentIdx + 1)}
+            >
+              Next →
+            </button>
+          ) : (
+            <button className="btn btn-primary" onClick={onSubmit}>
+              Submit exam
+            </button>
           )}
-          {currentIdx < total - 1
-            ? <button className="btn btn-primary" onClick={() => goTo(currentIdx + 1)}>Next →</button>
-            : <button className="btn btn-primary" onClick={onSubmit}>Submit exam</button>}
         </footer>
 
-        <div style={{ marginTop: 48, fontSize: 11.5, color: 'var(--ink-4)', display: 'flex', gap: 16, flexWrap: 'wrap' }}>
-          <span><span className="kbd">←</span> <span className="kbd">→</span> navigate</span>
-          <span><span className="kbd">F</span> flag</span>
-          {q.type === 'multiple-choice' && q.choices && (
-            <span><span className="kbd">1</span>–<span className="kbd">{q.choices.length}</span> select</span>
+        <div
+          style={{
+            marginTop: 48,
+            fontSize: 11.5,
+            color: "var(--ink-4)",
+            display: "flex",
+            gap: 16,
+            flexWrap: "wrap",
+          }}
+        >
+          <span>
+            <span className="kbd">←</span> <span className="kbd">→</span>{" "}
+            navigate
+          </span>
+          <span>
+            <span className="kbd">F</span> flag
+          </span>
+          {q.type === "multiple-choice" && q.choices && (
+            <span>
+              <span className="kbd">1</span>–
+              <span className="kbd">{q.choices.length}</span> select
+            </span>
           )}
         </div>
       </main>
@@ -197,7 +310,11 @@ export default function ExamRunner({ exam, state, setState, onSubmit, onExit }:
         {remainingMs != null && (
           <div className="meta-block">
             <div className="meta-label">Remaining</div>
-            <div className={`meta-value mono${timeUrgent ? ' timer-urgent' : ''}`}>{formatTime(Math.max(0, remainingMs))}</div>
+            <div
+              className={`meta-value mono${timeUrgent ? " timer-urgent" : ""}`}
+            >
+              {formatTime(Math.max(0, remainingMs))}
+            </div>
           </div>
         )}
         <div className="meta-block">
@@ -207,7 +324,9 @@ export default function ExamRunner({ exam, state, setState, onSubmit, onExit }:
         <div className="meta-block">
           <div className="meta-label">Mode</div>
           <div className="meta-value mono" style={{ fontSize: 13 }}>
-            {feedbackMode === 'immediate' ? 'Immediate feedback' : 'Grade at end'}
+            {feedbackMode === "immediate"
+              ? "Immediate feedback"
+              : "Grade at end"}
           </div>
         </div>
         <div className="meta-block notes-block">
@@ -230,5 +349,5 @@ export default function ExamRunner({ exam, state, setState, onSubmit, onExit }:
         )}
       </aside>
     </div>
-  )
+  );
 }

frontend/src/main.tsx

@@ -1,11 +1,14 @@
-import { StrictMode } from 'react'
-import { createRoot } from 'react-dom/client'
-import 'katex/dist/katex.min.css'
-import './index.css'
-import App from './App.tsx'
+import { StrictMode } from "react";
+import { createRoot } from "react-dom/client";
+import { BrowserRouter } from "react-router-dom";
+import "katex/dist/katex.min.css";
+import "./index.css";
+import App from "./App.tsx";
 
-createRoot(document.getElementById('root')!).render(
+createRoot(document.getElementById("root")!).render(
   <StrictMode>
-    <App />
+    <BrowserRouter>
+      <App />
+    </BrowserRouter>
   </StrictMode>,
-)
+);

frontend/src/types.ts

@@ -1,125 +1,124 @@
 // src/types.ts
 
 export type QuestionType =
-  | 'multiple-choice'
-  | 'multiple-select'
-  | 'short-answer'
-  | 'translation'
-  | 'math-input'
-  | 'essay'
-  | 'match'
-  | 'order'
+  | "multiple-choice"
+  | "multiple-select"
+  | "short-answer"
+  | "translation"
+  | "math-input"
+  | "essay"
+  | "match"
+  | "order";
 
 export interface Choice {
-  id: string
-  text: string
+  id: string;
+  text: string;
 }
 
 export interface MatchItem {
-  id: string
-  text: string
+  id: string;
+  text: string;
 }
 
 export interface QuestionImage {
-  src: string
-  alt?: string
-  caption?: string
+  src: string;
+  alt?: string;
+  caption?: string;
 }
 
 export interface QuestionAudio {
-  src: string
+  src: string;
 }
 
 export interface QuestionCode {
-  language: string
-  content: string
+  language: string;
+  content: string;
 }
 
 export interface QuestionTable {
-  headers: string[]
-  rows: string[][]
+  headers: string[];
+  rows: string[][];
 }
 
 export interface Question {
-  id: string
-  type: QuestionType
-  category?: string
-  points?: number
-  prompt: string
-  explanation?: string
-  image?: QuestionImage
-  audio?: QuestionAudio
-  code?: QuestionCode
-  table?: QuestionTable
-  svg?: string
-  answer?: string | string[] | Record<string, string>
-  acceptedForms?: string[]
-  caseSensitive?: boolean
-  ignorePunctuation?: boolean
-  ignoreAccents?: boolean
-  sourceLanguage?: string
-  targetLanguage?: string
-  choices?: Choice[]
-  minWords?: number
-  rubric?: string[]
-  left?: MatchItem[]
-  right?: MatchItem[]
-  items?: MatchItem[]
+  id: string;
+  type: QuestionType;
+  category?: string;
+  points?: number;
+  prompt: string;
+  explanation?: string;
+  image?: QuestionImage;
+  audio?: QuestionAudio;
+  code?: QuestionCode;
+  table?: QuestionTable;
+  svg?: string;
+  answer?: string | string[] | Record<string, string>;
+  acceptedForms?: string[];
+  caseSensitive?: boolean;
+  ignorePunctuation?: boolean;
+  ignoreAccents?: boolean;
+  sourceLanguage?: string;
+  targetLanguage?: string;
+  choices?: Choice[];
+  minWords?: number;
+  rubric?: string[];
+  left?: MatchItem[];
+  right?: MatchItem[];
+  items?: MatchItem[];
 }
 
 export interface Exam {
-  title: string
-  subtitle?: string
-  author?: string
-  timeLimitMinutes?: number | null
-  feedbackMode?: 'end' | 'immediate'
-  passingScore?: number
-  categories?: string[]
-  questions: Question[]
+  title: string;
+  subtitle?: string;
+  author?: string;
+  timeLimitMinutes?: number | null;
+  feedbackMode?: "end" | "immediate";
+  passingScore?: number;
+  categories?: string[];
+  questions: Question[];
 }
 
-export type FeedbackMode = 'immediate' | 'end'
+export type FeedbackMode = "immediate" | "end";
 
 export interface ExamState {
-  currentIdx: number
-  answers: Record<string, unknown>
-  flags: Record<string, boolean>
-  notes: string
-  revealed?: Record<string, boolean>
-  startedAt: number
-  completedAt?: number
-  feedbackMode: FeedbackMode
+  currentIdx: number;
+  answers: Record<string, unknown>;
+  flags: Record<string, boolean>;
+  notes: string;
+  revealed?: Record<string, boolean>;
+  startedAt: number;
+  completedAt?: number;
+  feedbackMode: FeedbackMode;
 }
 
 export interface HistoryEntry {
-  id: string
-  title: string
-  completedAt: number
-  elapsedMs: number
-  gradedCount: number
-  correctCount: number
-  totalPoints: number
-  scorePoints: number
-  passingScore: number
-  exam: Exam
-  state: ExamState
+  id: string;
+  title: string;
+  completedAt: number;
+  elapsedMs: number;
+  gradedCount: number;
+  correctCount: number;
+  totalPoints: number;
+  scorePoints: number;
+  passingScore: number;
+  exam: Exam;
+  state: ExamState;
 }
 
-export type GradeStatus = 'correct' | 'wrong' | 'ungraded' | 'unanswered'
+export type GradeStatus = "correct" | "wrong" | "ungraded" | "unanswered";
 
 export interface GradeResult {
-  status: GradeStatus
-  correct: boolean
-  points: number
+  status: GradeStatus;
+  correct: boolean;
+  points: number;
 }
 
-export type AppScreen = 'landing' | 'exam' | 'results' | 'review' | 'verify' | 'reset-password' | 'admin'
-export type ThemeMode = 'light' | 'dark'
-export type FontSize = 'small' | 'medium' | 'large'
-export type FeedbackTweak = 'auto' | 'immediate' | 'end'
+export type ThemeMode = "light" | "dark";
+export type FontSize = "small" | "medium" | "large";
+export type FeedbackTweak = "auto" | "immediate" | "end";
 
 export interface Tweaks {
-  theme: ThemeMode
-  fontSize: FontSize
-  feedbackMode: FeedbackTweak
+  theme: ThemeMode;
+  fontSize: FontSize;
+  feedbackMode: FeedbackTweak;
 }

frontend/src/utils/slug.test.ts

@@ -0,0 +1,26 @@
+import { describe, it, expect } from 'vitest'
+import { slugify } from './slug'
+
+describe('slugify', () => {
+  it('lowercases', () => {
+    expect(slugify('My Exam')).toBe('my-exam')
+  })
+  it('replaces spaces with hyphens', () => {
+    expect(slugify('hello world')).toBe('hello-world')
+  })
+  it('replaces special chars with hyphens', () => {
+    expect(slugify('Exam: Advanced!')).toBe('exam-advanced')
+  })
+  it('collapses consecutive hyphens', () => {
+    expect(slugify('Hello  World')).toBe('hello-world')
+  })
+  it('trims leading and trailing hyphens', () => {
+    expect(slugify('!hello!')).toBe('hello')
+  })
+  it('preserves numbers', () => {
+    expect(slugify('Exam 2024')).toBe('exam-2024')
+  })
+  it('handles empty string', () => {
+    expect(slugify('')).toBe('')
+  })
+})

frontend/src/utils/slug.ts

@@ -0,0 +1,7 @@
+export function slugify(title: string): string {
+  return title
+    .toLowerCase()
+    .replace(/[^a-z0-9]+/g, '-')
+    .replace(/-+/g, '-')
+    .replace(/^-|-$/g, '')
+}

frontend/vite.config.ts

@@ -1,23 +1,19 @@
-import { defineConfig } from 'vitest/config'
-import react, { reactCompilerPreset } from '@vitejs/plugin-react'
-import babel from '@rolldown/plugin-babel'
+import { defineConfig } from "vitest/config";
+import react, { reactCompilerPreset } from "@vitejs/plugin-react";
+import babel from "@rolldown/plugin-babel";
 
 export default defineConfig({
-  plugins: [
-    react(),
-    babel({ presets: [reactCompilerPreset()] })
-  ],
+  plugins: [react(), babel({ presets: [reactCompilerPreset()] })],
   server: {
     proxy: {
-      '/api': {
-        target: 'http://localhost:3001',
+      "/api": {
+        target: "http://localhost:3001",
         changeOrigin: true,
       },
     },
   },
   test: {
-    environment: 'node',
+    environment: "node",
     globals: true,
   },
-})
-
+});