diff --git a/docs/verification/ux-002-deterministic-theme-state.md b/docs/verification/ux-002-deterministic-theme-state.md
index 55076ff..21daf95 100644
--- a/docs/verification/ux-002-deterministic-theme-state.md
+++ b/docs/verification/ux-002-deterministic-theme-state.md
@@ -1,6 +1,6 @@
 # UX-002 deterministic theme state
 
-Updated: 2026-08-09
+Updated: 2026-08-15
 
 Status: `IMPLEMENTED — NOT VERIFIED`. Automated, build and local browser checks pass. Production and authenticated multi-user browser checks remain.
 
@@ -12,19 +12,20 @@ Theme changes also keyed `CssVarsProvider` and captured `themeMode` in the route
 
 ## Implemented contract
 
-- Preference resolution is explicit user key, then anonymous preference for a user without a saved choice, then the documented `System` default.
+- `jobtracker.themeMode` is the single browser preference. Login, logout and delayed `/auth/me` resolution cannot change it.
+- The first read migrates the former current-user/anonymous value into the canonical key, preserving existing choices.
 - Explicit Light and Dark ignore operating-system changes. Only System resolves through the current media query.
-- Auth user-key changes have a dedicated event. It updates theme state without re-running authentication requests or creating an event loop.
-- Relevant `storage` events update another tab without writing back. Unrelated storage events are ignored.
+- Canonical `storage` events update another tab without writing back. Auth and unrelated storage events are ignored.
 - MUI mode is changed in place through its color-scheme context with its private persistence disabled. The app/router tree is not keyed or recreated by theme changes.
-- A Next `beforeInteractive` bootstrap applies the same user/anonymous/System resolution before client application paint.
+- A Next `beforeInteractive` bootstrap applies the same canonical/migration/System resolution before client application paint.
+- Semantic Alert variants use explicit theme severity surfaces and foreground tokens; dark warning/error/info/success text no longer inherits dark-on-dark defaults.
 - Settings tabs are scrollable at narrow widths; this removes the mobile overflow discovered during the required theme browser pass.
 
 No backend, database, dependency, entitlement or production configuration changed.
 
 ## Verification
 
-- Focused deterministic theme suite: 6/6.
+- Focused deterministic theme and confirmation suites: 8/8.
 - Full frontend: 48/48 suites and 172/172 tests.
 - Production frontend build/TypeScript and `git diff --check`: pass.
 - Browser: explicit Light persisted across Settings → Dashboard navigation and refresh; explicit Dark switched without navigation; System selected the browser's dark preference; a second tab inherited Dark and changing it to Light updated the first tab without reload.
@@ -33,7 +34,7 @@ No backend, database, dependency, entitlement or production configuration change
 
 ## Remaining gates
 
-- Authenticated User A/User B scoped preference switching was proven at the storage/event unit boundary but not with two live browser accounts because no isolated API authentication environment was running.
+- Refresh/navigation and migration are automated; the revised canonical store still needs a real authenticated browser refresh pass before production verification.
 - A real operating-system preference-change event was tested at the resolver/provider boundary, not by changing the host OS during browser automation.
 - Production deployment/browser smoke is not authorized/configured.
 
@@ -42,8 +43,8 @@ No backend, database, dependency, entitlement or production configuration change
 - Screenshots: `docs/audits/evidence/ux-002/`
 - Commands/results: `docs/audits/verification-log.md` V-111–V-113
 - Tests: `job-tracker-ui/src/theme-state.test.tsx`
-- Implementation commit: `11734ee`
+- Initial implementation commit: `11734ee`; canonical-store/contrast correction: pending this change set.
 
 ## Rollback
 
-Revert `11734ee`. No data migration is required; existing `themeMode:<user>` and `themeMode:anon` values remain compatible. Reversion restores the prior delayed-login theme and provider/router remount behavior.
+Revert the canonical-store correction to restore account-scoped lookup. No destructive data migration is required; old `themeMode:<user>` values remain untouched and the canonical key can be removed independently.
diff --git a/job-tracker-ui/src/theme-state.test.tsx b/job-tracker-ui/src/theme-state.test.tsx
index 750e642..cd10158 100644
--- a/job-tracker-ui/src/theme-state.test.tsx
+++ b/job-tracker-ui/src/theme-state.test.tsx
@@ -10,6 +10,7 @@ import {
   resolveEffectiveThemeMode,
   setThemeModePref,
   subscribeToThemePreferenceChanges,
+  THEME_MODE_KEY,
 } from "./themePrefs";
 
 function setSystemDark(matches: boolean) {
@@ -36,7 +37,7 @@ describe("deterministic theme state", () => {
     setSystemDark(false);
   });
 
-  it("uses user preference, then anonymous preference, then the documented System default", () => {
+  it("uses one browser preference and falls back to System", () => {
     expect(getThemeModePref()).toBe("system");
     setThemeModePref("light");
     expect(getThemeModePref()).toBe("light");
@@ -47,12 +48,12 @@ describe("deterministic theme state", () => {
     expect(getThemeModePref()).toBe("dark");
 
     setAuthUserKey("user-b", false);
-    expect(getThemeModePref()).toBe("light");
-    window.localStorage.removeItem("themeMode:anon");
+    expect(getThemeModePref()).toBe("dark");
+    window.localStorage.removeItem(THEME_MODE_KEY);
     expect(getThemeModePref()).toBe("system");
   });
 
-  it("switches to the correct scoped preference on login and logout without a refresh", () => {
+  it("does not change theme on login or logout", () => {
     window.localStorage.setItem("themeMode:anon", "light");
     window.localStorage.setItem("themeMode:user-a", "dark");
     const observed: string[] = [];
@@ -61,11 +62,12 @@ describe("deterministic theme state", () => {
     setAuthUserKey("user-a", false);
     clearAuthClientState(false);
 
-    expect(observed).toEqual(["dark", "light"]);
+    expect(observed).toEqual([]);
+    expect(getThemeModePref()).toBe("light");
     unsubscribe();
   });
 
-  it("synchronizes relevant cross-tab storage changes without writing them back", () => {
+  it("synchronizes only the canonical cross-tab preference", () => {
     setAuthUserKey("user-a", false);
     const sync = jest.fn();
     const unsubscribe = subscribeToThemePreferenceChanges(sync);
@@ -73,11 +75,20 @@ describe("deterministic theme state", () => {
     window.dispatchEvent(new StorageEvent("storage", { key: "themeMode:user-a", newValue: "dark" }));
     window.dispatchEvent(new StorageEvent("storage", { key: "unrelated", newValue: "value" }));
     window.dispatchEvent(new StorageEvent("storage", { key: "authUserKey", newValue: "user-b" }));
+    window.dispatchEvent(new StorageEvent("storage", { key: THEME_MODE_KEY, newValue: "dark" }));
 
-    expect(sync).toHaveBeenCalledTimes(2);
+    expect(sync).toHaveBeenCalledTimes(1);
     unsubscribe();
   });
 
+  it("migrates the previous account-scoped preference", () => {
+    setAuthUserKey("user-a", false);
+    window.localStorage.setItem("themeMode:user-a", "light");
+
+    expect(getThemeModePref()).toBe("light");
+    expect(window.localStorage.getItem(THEME_MODE_KEY)).toBe("light");
+  });
+
   it("uses system preference only for System mode", () => {
     expect(resolveEffectiveThemeMode("light", true)).toBe("light");
     expect(resolveEffectiveThemeMode("dark", false)).toBe("dark");
@@ -86,7 +97,7 @@ describe("deterministic theme state", () => {
   });
 
   it("applies the saved preference before the client application renders", () => {
-    window.localStorage.setItem("themeMode:anon", "light");
+    window.localStorage.setItem(THEME_MODE_KEY, "light");
     setSystemDark(true);
 
     new Function(THEME_BOOTSTRAP_SCRIPT)();
diff --git a/job-tracker-ui/src/theme.ts b/job-tracker-ui/src/theme.ts
index 68d03f2..9a0a7a3 100644
--- a/job-tracker-ui/src/theme.ts
+++ b/job-tracker-ui/src/theme.ts
@@ -306,6 +306,21 @@ export const getTheme = (_mode: "light" | "dark") => {
         }),
       },
     },
+    MuiAlert: {
+      styleOverrides: {
+        root: {
+          alignItems: "flex-start",
+        },
+        standardError: ({ theme }: any) => ({ backgroundColor: theme.vars.palette.error.lighter, color: theme.vars.palette.error.darker, "& .MuiAlert-icon": { color: theme.vars.palette.error.main } }),
+        standardWarning: ({ theme }: any) => ({ backgroundColor: theme.vars.palette.warning.lighter, color: theme.vars.palette.warning.darker, "& .MuiAlert-icon": { color: theme.vars.palette.warning.main } }),
+        standardInfo: ({ theme }: any) => ({ backgroundColor: theme.vars.palette.info.lighter, color: theme.vars.palette.info.darker, "& .MuiAlert-icon": { color: theme.vars.palette.info.main } }),
+        standardSuccess: ({ theme }: any) => ({ backgroundColor: theme.vars.palette.success.lighter, color: theme.vars.palette.success.darker, "& .MuiAlert-icon": { color: theme.vars.palette.success.main } }),
+        outlinedError: ({ theme }: any) => ({ borderColor: theme.vars.palette.error.main, color: theme.vars.palette.error.darker, "& .MuiAlert-icon": { color: theme.vars.palette.error.main } }),
+        outlinedWarning: ({ theme }: any) => ({ borderColor: theme.vars.palette.warning.main, color: theme.vars.palette.warning.darker, "& .MuiAlert-icon": { color: theme.vars.palette.warning.main } }),
+        outlinedInfo: ({ theme }: any) => ({ borderColor: theme.vars.palette.info.main, color: theme.vars.palette.info.darker, "& .MuiAlert-icon": { color: theme.vars.palette.info.main } }),
+        outlinedSuccess: ({ theme }: any) => ({ borderColor: theme.vars.palette.success.main, color: theme.vars.palette.success.darker, "& .MuiAlert-icon": { color: theme.vars.palette.success.main } }),
+      },
+    },
     MuiPopover: {
       styleOverrides: {
         paper: ({ theme }: any) => ({
diff --git a/job-tracker-ui/src/themeBootstrap.ts b/job-tracker-ui/src/themeBootstrap.ts
index 2434052..e8cc7a9 100644
--- a/job-tracker-ui/src/themeBootstrap.ts
+++ b/job-tracker-ui/src/themeBootstrap.ts
@@ -5,7 +5,9 @@ export const THEME_BOOTSTRAP_SCRIPT = `(() => {
       return value === "light" || value === "dark" || value === "system" ? value : null;
     };
     const userKey = window.localStorage.getItem("authUserKey") || "anon";
-    const preference = read("themeMode:" + userKey) || (userKey !== "anon" ? read("themeMode:anon") : null) || "system";
+    const legacyPreference = read("themeMode:" + userKey) || (userKey !== "anon" ? read("themeMode:anon") : null);
+    const preference = read("jobtracker.themeMode") || legacyPreference || "system";
+    if (!read("jobtracker.themeMode") && legacyPreference) window.localStorage.setItem("jobtracker.themeMode", legacyPreference);
     const mode = preference === "dark" || (preference === "system" && window.matchMedia("(prefers-color-scheme: dark)").matches) ? "dark" : "light";
     document.documentElement.setAttribute("data-color-scheme", mode);
     document.documentElement.style.colorScheme = mode;
diff --git a/job-tracker-ui/src/themePrefs.ts b/job-tracker-ui/src/themePrefs.ts
index 6a471d1..390392a 100644
--- a/job-tracker-ui/src/themePrefs.ts
+++ b/job-tracker-ui/src/themePrefs.ts
@@ -1,19 +1,16 @@
-import { AUTH_USER_CHANGED_EVENT, getAuthUserKey } from "./auth";
+import { getAuthUserKey } from "./auth";
 
 export type ThemeModePref = "system" | "light" | "dark";
 export type EffectiveThemeMode = "light" | "dark";
 
 export const DEFAULT_THEME_MODE: ThemeModePref = "system";
+export const THEME_MODE_KEY = "jobtracker.themeMode";
 const THEME_KEY_PREFIX = "themeMode:";
 
 export function getUserKeyFromToken(): string {
   return getAuthUserKey();
 }
 
-function k(base: string) {
-  return `${base}:${getUserKeyFromToken()}`;
-}
-
 function readThemeMode(key: string): ThemeModePref | null {
   try {
     const raw = window.localStorage.getItem(key);
@@ -24,19 +21,28 @@ function readThemeMode(key: string): ThemeModePref | null {
 }
 
 export function getThemeModePref(): ThemeModePref {
+  const savedMode = readThemeMode(THEME_MODE_KEY);
+  if (savedMode) return savedMode;
+
+  // Migrate the former account-scoped values once. Theme is a browser UI
+  // preference, so changing auth state must never change the visible scheme.
   const userKey = getUserKeyFromToken();
   const savedUserMode = readThemeMode(`${THEME_KEY_PREFIX}${userKey}`);
-  if (savedUserMode) return savedUserMode;
-  if (userKey !== "anon") {
-    const anonymousMode = readThemeMode(`${THEME_KEY_PREFIX}anon`);
-    if (anonymousMode) return anonymousMode;
+  const legacyMode = savedUserMode ?? (userKey !== "anon" ? readThemeMode(`${THEME_KEY_PREFIX}anon`) : null);
+  if (legacyMode) {
+    try {
+      window.localStorage.setItem(THEME_MODE_KEY, legacyMode);
+    } catch {
+      // The migrated value still applies for this render when storage is unavailable.
+    }
+    return legacyMode;
   }
   return DEFAULT_THEME_MODE;
 }
 
 export function setThemeModePref(v: ThemeModePref) {
   try {
-    window.localStorage.setItem(k("themeMode"), v);
+    window.localStorage.setItem(THEME_MODE_KEY, v);
   } catch {
     // Keep the in-memory selection even when storage is unavailable.
   }
@@ -49,12 +55,10 @@ export function resolveEffectiveThemeMode(preference: ThemeModePref, systemPrefe
 
 export function subscribeToThemePreferenceChanges(sync: () => void) {
   const onStorage = (event: StorageEvent) => {
-    if (event.key === "authUserKey" || event.key?.startsWith(THEME_KEY_PREFIX)) sync();
+    if (event.key === THEME_MODE_KEY) sync();
   };
-  window.addEventListener(AUTH_USER_CHANGED_EVENT, sync);
   window.addEventListener("storage", onStorage);
   return () => {
-    window.removeEventListener(AUTH_USER_CHANGED_EVENT, sync);
     window.removeEventListener("storage", onStorage);
   };
 }